VS V6 complete and comprehensive DTC/Error codes list

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https://forums.justcommodores.com.au/threads/checking-error-codes-vr-vs-revised.22307/

DTC 12:
System pass. (OK)

DTC 13:
RIGHT HAND (RH) NO OXYGEN SENSOR SIGNAL

The exhaust oxygen sensor is mounted in the exhaust pipe with the sensing portion exposed to exhaust gases. After the sensor is hot (360 degrees C), it becomes a voltage generator, producing a "changing" voltage. This voltage ranges from approximately 100 millivolts with a "lean" exhaust, to 900 millivolts with a "rich" exhaust. When the sensor is cold (below 360 degrees C) it acts like an open circuit and produces almost no voltage. The PCM supplies a very small "bias" voltage between terminals D13 and D14, normally about 450 millivolts. If measured with the 10 megohm digital voltmeter, it may measure as low as 350 millivolts. When the sensor is hot, it's output overshadows this PCM supplied voltage.

When the fuel system is correctly operating in the closed-loop mode, the sensor output is changing several times per second, going above and below a mid-point range of 490-500 millivolts at a hot idle. The PCM compares the voltage between the sensor signal and sensor earth terminals and decides the needed fuel mixture correction. The PCM also monitors the changing voltage, watching for transitions above and below the mid-point range, to decide when to operate in the closed-loop mode. An open circuit, defective, or contaminated sensor could cause the voltage to stay within a 410-477 millivolt band too long, keeping the system in open-loop and setting a DTC 13.

DTC 13 will set if no DTC 19, DTC 21 or DTC 22 is active and all conditions exist for 26 seconds:
Engine has been running for at least 4 minutes and 10 seconds, and...
Engine coolant temperature is more than 85 degrees C, and
Throttle Position (TP) sensor voltage indicates the throttle is open more than 15% and RH O2 sensor voltage stays between 410-477 millivolts.

*When DTC 13 is active (MIL) ("Check Powertrain" lamp "ON"), the PCM will operate the fuel system in the open-loop mode.

DTC 14:
ENGINE COOLANT TEMPERATURE (ECT) (SIGNAL VOLTAGE LOW)

The Engine Coolant Temperature (ECT) sensor uses a thermistor to control the signal voltage to the PCM. The PCM applies about 5 volts on circuit 410 to the sensor. When the engine coolant is cold, the sensor (thermistor) resistance is high, therefore the PCM will see high signal voltage about 4.0 - 4.5 volts.
As the engine coolant warms, the sensor resistance becomes less, and the PCM sees a lower signal voltage. At normal engine operating temperature (85 degrees C to 95 degrees C), the voltage should measure about 2.2 to 1.8 volts.

A DTC 14 may enable TCC operation when cold.


Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. DTC 14 will set if:
Time since engine started is greater than 10 seconds and ECT sensor signal voltage is less than 0.3 volts, indicating an engine coolant temperature above 140 C for one second.
3. This test will determine if circuit 410 is shorted to earth which will cause the conditions for DTC 14.
4. If checking resistance at the engine coolant temperature sensor is difficult because of sensor location, disconnect the PCM connectors and check resistance between engine coolant temperature signal and sensor earth terminals.

DTC 15:
ENGINE COOLANT TEMPERATURE (ECT) (SIGNAL VOLTAGE HIGH)

The Engine Coolant Temperature (ECT) sensor uses a thermistor to control the signal voltage to the PCM. The PCM applies about 5 volts on circuit 410 to the sensor. When the engine coolant is cold, the sensor (thermistor) resistance is high, therefore the PCM will see high signal voltage, about 4 - 4.5 volts.
As the engine coolant warms, the sensor (thermistor) resistance becomes less, and the PCM sees a lower signal voltage. At normal engine operating temperature (85 degrees C to 95 degrees C), the voltage will measure about 2.2 to 1.8 volts.

A Diagnostic Trouble Code 14 may enable TCC operation when cold.


Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

1. DTC 15 will set if:
Time since engine started is greater then 10 seconds, and ECT input signal voltage is greater than 4.74 volts, indicating an engine coolant temperature less than -37 degrees C for one second
2. This test simulates a Diagnostic Trouble Code 15. If the PCM recognises the low signal voltage, (high temperature) and the Tech 1 "Scan" tool reads 130 C or above, the PCM and wiring are OK.
3. This test will determine if circuit 410 is open. There should be an open circuit voltage of 5 volts present at Engine Coolant Temperature (ECT) sensor harness connector if measured with a DVM. By jumpering this 5 volt signal to earth, the PCM should recognise this change.

DTC 16:
ENGINE COOLANT TEMPERATURE (ECT) (SIGNAL VOLTAGE UNSTABLE)

The Engine Coolant Temperature (ECT) sensor is a thermistor located in a coolant passage on the engine. When engine coolant temperature is cold, the sensor has a high resistance. As temperature increases, the resistance of the sensor decreases. The PCM provides a five volt signal to the engine coolant sensor, which is also connected to PCM earth. The PCM reads the voltage drop on the signal line to determine engine coolant temperature.

Test Description: Numbers below refer to step(s) on the diagnostic chart.

2. Diagnostic Trouble Code 16 will set if: The engine has been operating for more than 14 seconds, and ECT reading changes more than 400 mV in 200 milliseconds.

Diagnostic Aids:
When attempting to diagnose an intermittent problem, use the snapshot mode of the Tech 1 "Scan" tool, to review diagnostic information.
This DTC is more likely to set on a cold engine than on a hot engine because of the pull up resistors in the PCM.
When DTC 16 is set, the PCM will turn "ON" the engine cooling fan.
If DTC 16, 53 and 57 are set, check for short to voltage on "Diagnostic Test" line. circuit 451.

DTC 17:
PCM ERROR - ECT CIRCUIT

The PCM uses two different internal pull-up resistors to increase resolution throughout the entire range of engine operating temperatures. When the engine coolant temperature is less than 50 degrees C, the 4K ohm resistor is used. When temperature is above 50 degrees C, the PCM switches to the 348 ohm resistor. If the pull-up resistor does not switch, DTC 17 will set.

Test Description: Number(s) below refer to step(s) on the diagnostic chart.

2. DTC 17 will set if:
The engine has been operating for more than 10 seconds, and The pull-up resistor inside the PCM switches and there is less than a 60 mV change in the engine coolant temperature signal.

Diagnostic Aids:

DTC 17 is an internal fault within the PCM. The PCM must be replaced!
When DTC 17 is set, the PCM will turn "ON" the engine cooling fan.

DTC 19:
TP SENSOR STUCK

The Throttle Position (TP) sensor provides a voltage signal that changes relative to the throttle blade angle. Signal voltage will vary from about 0.25 to 1.25 volts at idle to about 4 volts at Wide Open Throttle (WOT).
The TP sensor signal is one of the most important inputs used by the PCM for transient fueling and transmission control and for most of the PCM control outputs.
Diagnostic Trouble Code (DTC) 19 is used to detect a stuck open or TP sensor. DTC 19 detects if the TP sensor does not return with the throttle blade when decelerating.

Diagnostic Trouble Code 19 will set if:
The Throttle Position (TP) sensor percentage of opening angle indicated is greater than the RPM that can be reached with a mass air flow reading of less than 301 mg/cyl for 20 seconds.
For example: If the TP sensor indicated that the angle of opening is greater than 20% and the engine is operating at 800 RPM or less, with a MAF sensor reading of 301 mg/cyl or less, then the TP sensor is stuck open.

DTC 21:
THROTTLE POSITION (TP) (SIGNAL VOLTAGE HIGH)

The Throttle Position (TP) sensor provides a voltage signal that changes relative to the throttle blade angle. TP sensor signal voltage will vary from about 0.25 to 1.25 volts at idle to about 4 volts at Wide Open Throttle (WOT).
The TP sensor signal is one of the most important inputs used by the PCM for fueling and transmission control and for most of the PCM control outputs.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. DTC 21 will set if:
TP sensor signal voltage is greater than 4.9 for two seconds.
3. With the TP sensor disconnected, the TP sensor signal voltage should go low if the PCM and wiring are OK.
4. Probing circuit 452 with a test light connected to 12 volts checks the sensor earth circuit. A faulty sensor earth will cause a DTC 21.

DTC 22:
THROTTLE POSITION (TP) (SIGNAL VOLTAGE LOW)

The Throttle Position (TP) sensor provides a voltage signal that changes relative to the throttle blade. Signal voltage will vary from about 0.25 to 1.25 volts at idle to about 4 volts at Wide Open Throttle (WOT).
The TP sensor signal is one of the most important inputs used by the PCM for transient fueling and transmission control and for most of the PCM control outputs.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. DTC 22 will set if:
TP sensor signal input voltage is less than about 0.2 volts for two seconds.
3. This test simulates a Diagnostic Trouble Code 21: (high voltage) If the PCM recognises the high signal voltage and the Tech 1 "Scan" tool reads over 4 volts or above, the PCM and wiring are OK.
4. This simulates a high signal voltage to check for an open in circuit 417. The Tech 1 "Scan" tool will not read up to 12 volts, but what is important is that the PCM recognises the signal on circuit 417.

DTC 23:
INTAKE AIR TEMPERATURE (IAT) (SIGNAL VOLTAGE HIGH)

The Intake Air Temperature (IAT) sensor uses a thermistor to control the signal voltage to the PCM. The PCM applies a voltage (about 5 volts) on circuit 472 to the sensor. When the intake air is cold, the sensor (thermistor) resistance is high, therefore, the PCM will sensor a high signal voltage. If the intake air is warm, the sensor (thermistor) resistance is low, therefore, the PCM will sense a low signal voltage.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. DTC 23 will set if:
IAT sensor signal voltage is more than 4.9 volts, indicating an intake air temperature below -38 C for one second.
3. A Diagnostic Trouble Code 23 will set, due to an open sensor, wire or connection. This test will determine if the wiring and PCM are OK.
6. This will determine if the IAT sensor signal (circuit 472) or the IAT sensor earth (circuit 469) is open.

DTC 24:
NO VEHICLE SPEED SIGNAL (AUTOMATIC TRANSMISSION)

The vehicle speed sensor circuit consists of a magnetic induction type sensor, and wiring. Gear teeth cut in the outside diameter of the output shaft alternately interrupt the permanent magnetic field inducing an alternating voltage in the sensor. This voltage is transmitted to the PCM to determine vehicle speed. The speedometer applies 12 volts on circuit 123. The PCM alternately earths circuit 123 when the drive wheels are turning. This pulsing action takes place about 6250 times per kilometre and the speedometer and BCM will calculate vehicle speed based on the time between "pulses."

Test Description: Number(s) below refer to Step number(s) on the diagnostic chart.

1. Diagnostic Trouble Code 24 will set if:
Range selected is not in park or neutral.
Engine speed is greater than 3000 RPM.
Transmission output is less than 250 RPM.
TP sensor between 10% and 100%.
All conditions above met for about 3 seconds.

DTC 24 Will set if the VSS circuit is open from a standing stop. As the vehicle is accelerated the transmission will shift from 1st to 2nd gear at approximately 54 km/h. If the VSS signal is not present, DTC 24 will be set.

4. Output voltage will vary with speed from a minimum of 0.5 volts AC at 100 RPM, to more than 100 volts AC at 8000 RPM, with no load on the circuit on the vehicle, with the engine at 4000 RPM and in 4th gear, the voltage will be approximately 25 volts AC.
6. Diagnostic Trouble Code 24 is being caused by a faulty PCM, faulty PROM or an incorrect PROM.

DTC 25:
INTAKE AIR TEMPERATURE (IAT) (SIGNAL VOLTAGE LOW)

The Intake Air Temperature (IAT) sensor uses a thermistor to control the signal voltage to the PCM. The PCM applies a voltage (about 5 volts) on circuit 472 to the sensor. When manifold intake air is cold (such as when the engine is first started on a cold day), the sensor (thermistor) resistance is high, therefore, the PCM will sense a high signal voltage. If the manifold intake air is warm, the sensor (thermistor) resistance is low, therefore, the PCM will sense a low signal voltage.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. DTC 25 will set if:
Engine has been operating for more than 60 seconds, and
Intake Air Temperature (IAT) signal voltage is less than 0.3 volts, indicating an intake air temperature above 147 degrees C for one second.

DTC 26:
INTAKE AIR TEMPERATURE (IAT) (SIGNAL VOLTAGE UNSTABLE)

The Intake Air Temperature (IAT) sensor is a thermistor located in the inlet manifold. When the intake air temperature is cold, the sensor has a high resistance. As temperature increases, the resistance of the sensor decreases. The PCM provides a five volt signal to the intake air temperature sensor which is also connected to PCM earth. The PCM reads the voltage drop on the signal line to determine intake air temperature.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. Diagnostic Trouble Code 26 will set if:
The engine has been operating for more than 10 seconds, and
IAT Sensor reading changes more than 140 mV in 100 milliseconds.

DTC 28:
TRANSMISSION FLUID PRESSURE SWITCH ASSEMBLY (PSA) CIRCUIT FAULT

The Pressure Switch Assembly (PSA) is actually five pressure switches combined into one unit and mounted on the valve body. The PCM supplies battery voltage to the Pressure Switch Assembly (PSA) on three separate wires. By earthing one or more of these circuits through various combinations of the pressure switches inside the pressure switch assembly the PCM detects what gear range has been selected by the vehicle operator.

Test Description: Number(s) below refer to step number(s) on the diagnostic table.

2.This test compares the indicated range to the range actually selected.

Diagnostic Aids:
A poor connection or open wire cannot cause DTC 28. When DTC 28 is set, the transmission will have TCC apply, harsh shifts and no 4th gear if in hot mode.
DTC 28 will set if the PCM detects an "Illegal" PSA combination for 5 seconds. Any fault in range signal "B" can not set DTC 28. For a complete diagnosis of the transmission fluid pressure switch assembly (PSA) refer to "Functional Checks" in Section 6C1-2C in this Volume.

DTC 31:
THEFT DETERRENT SIGNAL MISSING

When the ignition is turned "ON", the PCM will send a message on circuit 1221 to the BCM asking for permission to start. When the BCM receives this message, it instantly enables the starter and sends a message back to the PCM. The message says that the proper ignition key has been used to turn the ignition and that it is OK for the PCM to enable the fuel injectors to start the vehicle. If the BCM does not receive communications from the PCM when the ignition is switched "ON", then the starter motor will be enabled after a one second delay.

DTC 31 will be set, if the PCM sends 20 messages to the BCM and does not receive a message back saying it is OK to start.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. If the engine cranks after a one second delay it means the BCM did not see a message from the PCM when the ignition was turned "ON".
3. An open or short to earth on circuit 1221 will disable any communication of serial data.

DTC 32:
MASS AIR FLOW (MAF) OUT OF RANGE

The Mass Air Flow (MAF) sensor measures the flow of air which passes through it in a given time. The PCM uses this information to monitor the operating condition of the engine for fuel delivery calculations. A large quantity of air movement indicates acceleration, while a small quantity indicates deceleration or idle.
The MAF sensor produces a frequency signal which cannot be easily measured.
The MAF sensor can be diagnosed using the procedures on this chart.
With DTC 32 set, the PCM will use a default value for air flow based on throttle position, and engine speed and some vehicle performance will return. When DTC 32 is set the MIL "Check Powertrain Lamp" will be illuminated.

Test Description: Number(s) below refer to step(s) on the diagnostic chart.

2. DTC 32 will set if:
Engine running.
No MAF signal for over 2 seconds.
5. Verifies that both ignition feed voltage and a good earth circuit are available.
6. This step checks to see if PCM recognises a problem.
7. A voltage reading at sensor harness connector terminal "A" of less than 4 or over 6 volts indicates a fault in circuit 792 or poor connection.

DTC 35:
IDLE SPEED ERROR

Review the description of the Idle Air Control (IAC) valve operation, 1.5 Fuel Control System, Section 6C1-1 GENERAL INFORMATION - V6 ENGINE in this Volume.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

DTC 35 will set if:
Engine is idling.
TP sensor is less than 2% and VSS is less than
5 km/h for greater than 15 seconds.
IAT is less than 73 C.
IAC is at 0 or 255.
Engine speed is greater than 250 RPM (above requested idle speed) for 5 seconds.

DTC 41:
IGNITION ELECTRONIC SPARK TIMING (EST) OUTPUT CIRCUIT FAULT

There are two modes of ignition system operation: BYPASS mode, and ELECTRONIC SPARK TIMING mode. The Bypass mode is normally used while starting the engine, while the Electronic Spark Timing mode is used to allow the PCM to control the ignition system after the engine is running. The PCM controls a "Bypass control circuit", used to control the ignition module between the two different ignition system modes.
The PCM's Electronic Spark Timing (EST) output circuitry generates EST output pulses anytime crankshaft reference input pulses are received. The PCM also monitors it's EST output terminal, to monitor if and when EST pulses are present.

When the ignition system is operating in the Bypass mode (such as when the engine is cranking), the ignition module earths the EST pulses coming from the PCM. Because the EST pulses should be earthed through the ignition module during Bypass mode operation., the PCM should not detect EST pulses on it's EST output terminal.
If the EST output circuit wire between the PCM and the ignition module has an "open circuit" fault, then the ignition module can not earth the PCM's EST output pulses. If the PCM detects two EST pulses during the first 3 crankshaft reference input pulses, indicating the EST circuit is open, the PCM will set a DTC 41.

DTC 41 can also be set if the Bypass control circuit is shorted to voltage. If this where to happen, the PCM's EST monitor would not sense the EST signal being earthed in the ignition module while cranking , and DTC 41 would be set.

Test Description: Number(s) below refer to Step numbers on the Diagnostic Chart.

2. DTC 41 will set if:
Ignition switch is "ON", and
PCM had detected at least 2 EST output pulses, during the first 3 crankshaft reference signal pulses received from the ignition module, while cranking to start the engine.
4. This Step checks to see if circuit 424 is shorted to voltage.
8. This Step checks to see if circuit 423 is open.

Diagnostic Aids:
Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
Damaged Harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the ignition module, turn the ignition "ON". Connect and observe a voltmeter connected between the Bypass control circuit and B+, while moving connectors and wiring harness related to the ignition module. A change in voltage will indicate the location of the fault.

DTC 42:
IGNITION BYPASS CIRCUIT FAULT

There are two modes of ignition system operation: BYPASS mode, and ELECTRONIC SPARK TIMING mode. The Bypass mode is normally used while starting the engine, while the Electronic Spark Timing mode is used to allow the PCM to control the ignition system after the engine is running. The PCM controls a "Bypass control circuit", used to control the ignition module between the two different ignition system modes.
The PCM's Electronic Spark Timing (EST) output circuitry generates EST output pulses anytime crankshaft reference input pulses are received. The PCM also monitors it's EST output terminal, to monitor if and when EST pulses are present.

When the ignition system is operating in the Bypass mode (such as when the engine is cranking), the ignition module earths the EST pulses coming from the PCM. Because the EST pulses should be earthed through the ignition module during Bypass mode operation., the PCM should not detect EST pulses on it's EST output terminal.
When the engine is started, the PCM applies 5 volts to the Bypass control circuit. When received by the ignition module, this 5 volts control causes the ignition module to release the earth from the EST pulses coming from the PCM. The ignition module will then use the EST pulses to operate the ignition system. When this occurs, the PCM will correctly detect EST pulses at it's EST output terminal.

If the Bypass control circuit has as open fault or short to earth, or if the EST circuit has a short to earth or short to voltage, the PCM cannot control the ignition module to release the EST pulses from being earthed. Because the PCM also monitors it's EST output terminal for EST pulses, if it detects no EST pulses after it has "turned on" the 5 volts to the Bypass control circuit, and the engine speed goes above 1600 RPM, a DTC 42 will be set.

Test Description: Number(s) below refer to Step numbers on the Diagnostic Chart.

2.DTC 42 will set if:
Engine speed is greater then 1600 RPM.
PCM has detected no EST output pulses for 200 milliseconds.
4. This step checks to see if circuit 423 is shorted to voltage.
7. This step checks to see if circuit 423 is shorted to earth.
10. This step checks to see if circuit 424 is shorted to earth.
12. This step checks to see if circuit 424 is open.
13. This step checks to see if the ignition module is capable of switching from Bypass to EST mode.

Diagnostic Aids:
Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
Damaged Harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the ignition module, turn the ignition "ON". Connect and observe a voltmeter connected between the Bypass control circuit and B+, while moving connectors and wiring harness related to the ignition module. A change in voltage will indicate the location of the fault.

DTC 43:
KNOCK SENSOR CIRCUIT FAULT

The Knock sensor is used to detect engine detonation, and the PCM will retard the Electronic Spark Timing (EST) based on the signal being received. The Knock sensor produces an AC signal which the PCM receives, so that under a no Knock condition circuit 815 would measure about 29 millivolts AC when the engine is running at idle. The amplitude and signal frequency is dependent upon the Knock level.

Test Description: Number(s) below refer to Step number(s) on the Diagnostic Chart.

2. DTC 43 will set if:
Engine has been running longer then 10 seconds.
Engine Coolant Temperature is greater then 65 degrees C.
TP sensor signal is greater than 22%.
Engine speed is greater then 2000 RPM.
No Knock signal for 3 seconds.
This Step determines if conditions for DTC 43 still exist.
6. This Step determines if the Knock sensor resistance is between 50,000 ohms and 100,000 ohms.

NOTE: If the resistance is at 50,00 ohms, this means that both Knock sensor shunt resistors are OK. If the resistance is at 100,000 ohms, this means that one of the Knock sensor is open, but the Knock sensor system will still work properly with only one Knock sensor functioning.
Check each "Knock" sensor for an open circuit 815 between splice and sensor. If wiring is OK, replace "Knock" sensor.

7. The signal should be present at the Knock sensor terminal during these test conditions.

Diagnostic Aids:
If circuit 815 is not open or shorted to earth, the most likely cause is an open circuit in the PCM. It is possible that a faulty PCM could be the cause of the DTC 43, and it should be replaced.

 

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DTC 44:
RIGHT HAND (RH) LEAN EXHAUST INDICATION

The PCM supplies a voltage of about 450 millivolts between terminal "D14" and "D13". The Oxygen (O2) sensor varies the voltage within a range of about 1 volt if the exhaust is rich, down through about 100 millivolts, if exhaust is lean.
The sensor is like an open circuit and produces no voltage when it is below about 360 degrees C. An open sensor circuit or cold sensor causes "Open Loop" operation.

DTC 45:
RIGHT HAND (RH) RICH EXHAUST INDICATION

The PCM supplies a voltage of about 450 millivolts between terminal "D13" and "D14". The Oxygen (O2) sensor varies the voltage within a range of about 1 volt, if the exhaust is rich and down through about 100 millivolts if exhaust is lean.
The sensor produces no voltage when it is below about 360 degrees C. An open sensor circuit or cold sensor causes "Open Loop" operation.

DTC 46:
NO REFERENCE PULSES WHILE CRANKING

This DTC is intended to help in diagnosing a no-start condition. Any time the distributor is turning, the ignition module should generate the crankshaft reference pulses that the PCM should be receiving. Fuel injection pulses are "timed" from the crankshaft pulses, and without them no injection pulses will occur. The PCM can determine when these crankshaft pulses should be present, but aren't.
As with any engine while being cranked, there is a small amount of inlet manifold vacuum. Also while cranking, the battery voltage will be less than 11 volts. If the PCM's MAF sensor input detects manifold vacuum and the ignition voltage input detects less than 11 volts and there are no distributor reference input pulses, a DTC 46 will set.

NOTE: It is possible for the ignition system to provide spark, yet there may not be any distributor reference pulses at the PCM.
DTC 46 will set if all the following conditions are present for more than 2 seconds:
Voltage at PCM ignition voltage input terminal "A4" is below 1 volts, and
MAF sensor input is above 2048 Hz, and
No distributor reference input pulses at PCM terminal "D12".

DTC 47:
18X REFERENCE SIGNAL MISSING

The 18X signal (circuit 647) is used by the PCM to improve ignition timing accuracy during crank and at engine speeds of up to 2000 RPM. The 18X signal circuit allows the use of EST mode below 400 RPM, eliminating the need to utilise bypass mode during startup, and also allows the PCM to calculate true crankshaft position in 1/6 the time that use of the crankshaft reference signal would permit.
During normal operation, the PCM uses the 18X signal to control ignition timing until the engine speed exceeds 2000 RPM, at which time the crankshaft reference signal (circuit 430) is used. When conditions for setting DTC 47 exist, the crankshaft reference signal is used by the PCM to control EST. This condition will cause bypass mode to be used for ignition timing below 400 RPM and EST ignition timing to be degraded below 2000 RPM.

DTC 47 will set if:
The engine is running.
The PCM detects 240 (80 crank revolutions) crankshaft reference pulses, and no 18X signal pulses.
The engine RPM is below 1200.
DTC 47 does not illuminate the "Check Powertrain" lamp.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

4. If a window on the harmonic balancer is interfering with the 18X Hall-Effect switch, the ignition module will earth the 18X signal. Starter may have to be bumped several times to obtain a voltage reading.
5. Voltage reading should be lower than that obtained with engine not running, indicating a pulsed reference signal.
8. Verifies that circuit 647 is not shorted to earth or open in the harness.

Diagnostic Aids:
An intermittent may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation.

Check for:
Backed out connector terminals or broken down insulation in circuit 647.
If connections and harness check OK, try monitoring voltage on circuit 647 with DVM while moving the related wiring harness and connectors with the engine idling. This may help to isolate the location of the malfunction.

DTC 48:
CAMSHAFT POSITION SIGNAL MISSING

During cranking, the ignition module monitors the dual crank sensor 3X signal. The 3X signal is used to determine the correct cylinder pair to spark first. After the 3X signal has been processed by the ignition module, it sends a crankshaft reference pulse to the PCM. When the PCM receives this pulse it will command all six injectors to open for one priming shot of fuel in all cylinders. After the priming, all six of the injectors are left "OFF" until the next crankshaft reference pulses from the ignition module (two crankshaft revolutions). This allows each cylinder a chance to use the fuel from the priming shot. During this waiting period, a cam signal will have been received by the PCM. Now the PCM begins to operate the injectors in sequential fueling mode by energising each injector based on true camshaft position. However, if the camshaft position signal is not present at startup, a DTC 48 will set and the PCM will energise all six injectors at the same time and continue to operate like this until the fault is corrected.

DTC 48 is set when the following conditions are met:
The engine is running.
Camshaft position sensor signal is not received by PCM for last 5 seconds.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.
3. This step verifies proper operation of circuits 633, 644, and 645.
4. This step verifies the integrity of circuit 630 from ignition module to PCM. If the voltage reading of "D3" drops slightly from 4.7 volts to approximately 4.1 volts, the camshaft sensor is pulling the signal line low, therefore the connection to the PCM is not good or the PCM is faulty. If the voltage remains at approximately 4.4 volts and is steady, continue with diagnosis.

DTC 49:
CAM/CRANK SIGNAL INTERMITTENT

During cranking, the ignition module monitors the dual crank sensor 3X signal. The 3X signal is used to determine the correct cylinder pair to spark first. After the 3X signal has been processed by the ignition module, it sends a crankshaft reference pulse to the PCM. When the PCM receives this pulse it will command all six injectors to open for one priming shot of fuel in all cylinders. After the priming, the injectors are left "OFF" for the next six crankshaft reference pulses from the ignition module (two crankshaft revolutions). This allows each cylinder a chance to use the fuel from the priming shot. During this waiting period, a cam signal will have been received by the PCM. Now the PCM begins to operate the injectors by energising each injector based on true camshaft position. With the engine running, the PCM monitors the cam and 18X signal pulses it receives and expects to see 36 18X signal pulses for each cam pulse. If the sequence of pulses is not correct for 15 occurrences, DTC 49 will set, indicating an intermittent problem with the cam signal or 18X signal "reference" signal.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. Determines if conditions necessary to set DTC 49 exist on this ignition cycle.
3. If 5 volts are not present at PCM harness connector terminal "D3", the cam sensor may be interfacing with the magnet in the camshaft sprocket. Bumping the starter should correct this condition.
6. If a failure is induced in the 18X signal circuit, the 5 volts on the circuit should change when the faulty wiring or connection is manipulated.
NOTE: If DTC 48 is set along with DTC 49, use DTC 48 chart for diagnosis.

DTC 51:
PROM ERROR

1.Was the "On-Board Diagnostic" (OBD) System Check performed?
2. Check that PROM is fully inserted into the PCM.
3.Replace PROM.
4.Clear DTCs and recheck for DTC 51

DTC 52:
SYSTEM VOLTAGE TOO HIGH - LONG TIME

Diagnostic Trouble Code (DTC) 52 will set when the engine is running and PCM terminal A4 voltage is greater than 16 volts for about 109 minutes.
During the time failure is present, the pressure control solenoid is turned OFF, the transmission shifts immediately to 3rd gear and TCC operation is inhibited. Additional codes may also set.

Test Description:

2. Normal Battery voltage is between 9.6 and 14.5 volts.
3. Checks to see if the voltage reading is due to the generator or the PCM. With the engine running, check voltage at the battery. If the voltage is above 14.5 volts, the PCM is OK.
4. Checks to see if generator is faulty under load condition. If the voltage is above 14.5 volts, refer to Section 6D1-1, CHARGING SYSTEM - V6 ENGINE in Volume 11A of the VR Series Service Manual.

Diagnostic Aids:

If diagnostic trouble code 52 is set, the transmission will have no TCC, maximum line pressure and 3rd gear only.

DTC 53:
SYSTEM VOLTAGE TOO HIGH

Diagnostic Trouble Code (DTC) 53 will set when the ignition is ON and PCM terminal A4 voltage is greater than 19.5 volts for about 2 seconds.
During the time failure is present, the pressure control solenoid is turned OFF, the transmission shifts immediately to 3rd gear and TCC operation is inhibited. Additional codes may also set.

Test Description: Number(s) below refer to step(s) on the diagnostic chart.

2. Normal Battery voltage is between 9.6 and 14.5 volts.
3. Checks to see if the voltage reading is due to the generator or the PCM. With the engine running, check voltage at the battery. If the voltage is above 14.5 volts, the PCM is OK.
4. Checks to see if generator is faulty under load condition. If the voltage is above 14.5 volts.

Note on Intermittents:

Charging battery with a battery and jump-starting engine, may set Diagnostic Trouble Code 53. If Diagnostic Trouble Code sets when an accessory is operated, check for poor connections or excessive current draw.
Diagnostic Aids:
If diagnostic trouble code 53 is set, the transmission will have no TCC, maximum line pressure and 3rd gear only.
If DTC 16, 53 and 57 are set, check for short to voltage on "Diagnostic Test" line, circuit 451.

DTC 54:
SYSTEM VOLTAGE UNSTABLE

Diagnostic Trouble Code (DTC) 54 will set when the ignition is "ON" and PCM terminal "A4" voltage changed more than 2.5 volts in 100 milliseconds.

Test Description: Number(s) below refer to the step(s) on the diagnostic chart.

2. Diagnostic Trouble Code 54 will set if: The last 25% of the samples for ignition feed voltage changes more than 2.5 volts in 100 milliseconds.

DTC 55:
PROM - ANALOG to DIGITAL (A/D) CONVERSION error

Replace PCM

DTC 57:
INJECTOR VOLTAGE MONITOR FAULT

The injector voltage monitor line is used so that the PCM will know the exact voltage the fuel injectors are operating at. This voltage is used to control the pulse width modulation of the fuel injectors. If the injector voltage monitor line drops more than 2.2 volts for more than 3 seconds, Diagnostic Trouble Code (DTC) 57 will set. This DTC will not turn "ON" the "Check Powertrain" lamp, but will have a DTC set in the PCM memory that can be read with the Tech 1 "Scan" tool and can be displayed by flashing out codes.

Test Description: Number(s) below refer to the step(s) on the diagnostic chart.

2.The injector voltage monitor line voltage drops more than 2.2 volt in 3 seconds.

Diagnostic Aids:
When the injector voltage monitor line voltage drops more than 2.2 volts, the PCM will operate on an incorrected value for 3 seconds until the DTC 57 is set. After the DTC 57 is set, the PCM will use the battery feed as the voltage value to control the fuel injectors base pulse width. Check PCM terminal connections for proper mating.
If DTC 16, 53 and 57 are set, check for short to voltage on "Diagnostic Test" line, circuit 451.

DTC 58:
TRANSMISSION FLUID TEMPERATURE (TFT) (SIGNAL VOLTAGE LOW)

The Transmission Fluid Temperature (TFT) sensor is a thermistor that controls the signal voltage to the PCM. The PCM applies about 5 volts on circuit 1227 to the sensor. When the transmission fluid is cold, the sensor (thermistor) resistance is high, therefore, the PCM will see high signal voltage.
As the transmission fluid temperature warms, the sensor thermistor resistance becomes less and the PCM sees a lower signal voltage at normal transmission operating temperature (approximately 82-94 degrees C). The voltage will measure about 2.0 to 1.5 volts.

Test Description: Number(s) below refer to circled step(s) on the diagnostic chart.

3. Diagnostic Trouble Code 58 will set if:
TFT sensor signal voltage indicates a transmission fluid temperature above 150 degrees C for 1 second.
4. This test will determine if circuit 1227 is shorted to earth which will cause the conditions for Diagnostic Trouble Code 58.
5. In this Volume, CHART 2.1 will diagnosis the transmission internal wiring harness.

DTC 59:
TRANSMISSION FLUID TEMPERATURE (TFT) (SIGNAL VOLTAGE HIGH)

The Transmission Fluid Temperature (TFT) sensor is a thermistor that controls the signal voltage to the PCM. The PCM applies about 5 volts on circuit 1227 to the sensor. When the transmission fluid is cold, the sensor resistance is high, therefore, the PCM will see high signal voltage.
As the transmission fluid warms, the sensor (thermistor) resistance becomes less and the PCM sees a lower signal voltage. At normal transmission operating temperature (approximately 82-94 degrees C), the voltage will measure about 2.0 to 1.5 volts.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. Diagnostic Trouble Code 59 will set if:
TFT sensor signal voltage indicates a transmission fluid temperature below - 37 degrees C for 1 second.
3. This test simulates a Diagnostic Trouble Code 58. If the PCM recognises the low signal 0 voltage (high temperature), and the Tech 1 "Scan" tool reads 130 degrees C or above, the PCM and wiring are OK.
4. This test will determine if circuit 1227 is open. There should be open circuit voltage of 5 volts present at the transmission fluid temperature sensor harness connector if measured with a DVM. By jumpering this 5 volt signal to earth, the PCM should recognise this change.

DTC 63:
LEFT HAND (LH) NO OXYGEN SENSOR SIGNAL

The exhaust oxygen sensor is mounted in the exhaust pipe with the sensing portion exposed to exhaust gases. After the sensor is hot (360 degrees C), it becomes a voltage generator, producing a "changing" voltage. This voltage ranges from approximately 100 millivolts with a "lean" exhaust, to 900 millivolts with a "rich" exhaust. When the sensor is cold (below 360 degrees C) it acts like an open circuit and produces almost no voltage. The PCM supplies a very small "bias" voltage between terminals D15 and D16, normally about 450 millivolts. If measured with the 10 megohm digital voltmeter, it may measure as low as 350 millivolts. When the sensor is hot, it's output overshadows this PCM-supplied voltage.

When the fuel system is correctly operating in the closed-loop mode, the sensor output is changing several times per second, going above and below a mid-point range of 490-500 millivolts, at a hot idle. The PCM compares the voltage between terminals sensor signal and sensor earth terminals, and decides the needed fuel mixture correction. The PCM also monitors the changing voltage, watching for transitions above and below the mid-point range, to decide when to operate in the closed-loop mode. An open circuit, defective, or contaminated sensor could cause the voltage to stay within a 300-600 millivolt band too long, keeping the system in open-loop and setting a DTC 63.

*When DTC 63 is active ("Check Powertrain" lamp "ON") the PCM will operate the fuel system in the open-loop mode.
DTC 63 will set if no DTC 19, DTC 21 or 22 is active and all conditions exist for 26 seconds:
Engine has been running for at least 4 minutes and 10 seconds, and
Engine coolant temperature is more than 85 degrees C, and
Throttle Position (TP) sensor voltage indicates the throttle is open more than 15%, and LH O2 sensor voltage between 410-477 millivolts.

DTC 64:
LEFT HAND (LH) LEAN EXHAUST INDICATION

The PCM supplies a voltage of about 450 millivolts between terminals D16 and D15. The Oxygen (O2) sensor varies the voltage within a range of about 1 volt if the exhaust is rich, down through about 100 millivolts if exhaust is lean.
The sensor is like an open circuit and produces no voltage when it is below about 315 degrees C. An open sensor circuit or a cold sensor causes "Open Loop".

Test description: Number(s) below refer to step number(s) on the diagnostic chart.

2.DTC 64 is set when the O2 sensor signal voltage on circuit 412:
Remains below 200 millivolts for 46 seconds and
The system is operating in "Closed Loop" and
IAT sensor signal is below 75 degrees C.
4. DTC 64 or lean exhaust is most likely caused by one of the following:
O2 sensor wire. Sensor pigtail may be mispositioned and contacting the exhaust manifold.
Check for intermittent earth in wire between connector and sensor.
MAF sensor. A shifted MAF sensor could cause the fuel system to go lean.
Lean injector(s). Perform "Power Balance" test using Tech 1 "Scan" tool mode.
Fuel contamination. Water, even in small amounts, near the in-tank fuel pump inlet can be delivered to the injectors. The water causes a lean exhaust and can set a DTC 44 and/or DTC 64.
Fuel pressure. System will be lean if pressure is too low. It may be necessary to monitor fuel pressure while driving the vehicle at various road speeds and/or loads to confirm.
Exhaust leaks. If there is an exhaust leak, the engine can cause outside air to be pulled into the exhaust and past the sensor. Vacuum or crankcase leaks can cause a lean condition.
If the above are OK, it is a faulty Oxygen Sensor (O2S)

DTC 65:
LEFT HAND (LH) RICH EXHAUST INDICATION

The PCM supplies a voltage of about 450 millivolts between terminals "D14" and "D13". The Oxygen (O2) sensor varies the voltage within a range of about 1 volt, if the exhaust is rich, down through about 100 millivolts, if exhaust is lean.

The sensor produces no voltage when it is below about 360 degrees C. An open sensor circuit or cold sensor causes "Open Loop" operation.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

DTC 65 will be set if:
Throttle angle is between 9% and 30%.
The fuel control system is operating in the closed loop mode, and
O2 sensor signal voltage between PCM terminals D13 and D14 has remained above 780 millivolts (0.780 volts) for more than 35 seconds.
2. The O2 sensor MUST be at operating temperature before checking operation.
3. This step checks for a short to voltage on the O2 signal line.
7. Earthing circuit 412 causes a low O2 signal voltage. If the PCM and wiring are OK, the PCM should recognise the low voltage and confirm the lean signal.
8. A DTC 65 will most likely NOT be caused by a faulty O2 sensor. DTC 65 indicates a rich exhaust and diagnosis should begin with the items listed:
Fuel pressure. System will go rich, if pressure is too high. The PCM can compensate for some increase. However, if it gets too high, a DTC 45 or DTC 65 may be set.
Rich injector.
Leaking injector.
Check for fuel contaminated oil.
Short to voltage on circuit 412.
HEI shielding. An open earth circuit 453 (ignition system) may result in EMI, or induced electrical "noise." The PCM looks at this "noise" as reference pulses. The additional pulses result in a higher than actual engine speed signal. The PCM then delivers too much fuel, causing system to go rich. Engine tachometer will also show higher than actual engine speed, which can help in diagnosing this problem.
Canister purge. Check for fuel saturation. If full of fuel, check canister control and hoses.
MAF sensor. A shifted MAF sensor could cause the fuel system to go rich.
Check for leaking fuel pressure regulator diaphragm by checking vacuum line to regulator for fuel.
TP Sensor. An intermittent TP sensor output will cause the system to go rich, due to a false indication of the engine accelerating.

DTC 66:
3-2 CONTROL SOLENOID CIRCUIT FAULT

The 3-2 control solenoid is an "OFF - ON" type solenoid used to improve the 3-2 downshift by coordinating the apply rate of the 2-4 band with the release of hydraulic oil from the 3-4 clutch during a 3-2 downshift.
The PCM continually monitors the 3-2 control solenoid circuit for either a low or a high voltage depending on the commanded state of the circuit. When the transmission is in 1st gear the solenoid is normally "OFF". When the transmission is in 2nd gear or higher, the solenoid will be "ON". When the transmission downshifts, 3-2/4-2/3-1, the solenoid may be off.

For example: If the PCM commands the solenoid "ON," the voltage on that circuit should drop (approximately 0 volt) when the 3-2 control solenoid is earthed, if voltage stays up high (approximately 12 volts) for a period of time a DTC 66 will set.
If the 3-2 control solenoid is "OFF," the voltage on the circuit should remain high, if the voltage drops (approximately 0 volt) for some time, than DTC 66 will set. The 3-2 control solenoid feedback line must detect on inappropriate voltage status on the line for 4 seconds to set DTC 66.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.
2. Diagnostic Trouble Code 66 will set if:
Solenoid is commanded "ON", but the 3-2 control solenoid circuit voltage is high (approximately 12 volts).
OR
Solenoid is commanded "OFF", but the 3-2 control solenoid circuit voltage is low (approximately 0 volts).
Both conditions must be present for 4 seconds.
3. The first portion of the test checks for a shorted transmission internal harness or 3-2 control solenoid.
4. The second test verifies power supply to the 3-2 control solenoid.
5. This step checks circuit 897 for a short to earth. If circuit 897 is shorted to earth the 2-4 band would be slow to apply.
6. This test checks for a short to voltage on circuit 897.
7. The final test verifies that circuit 897 is not open.

Diagnostic Aids:
Be sure to check all connections especially those at the transmission pass-thru connector.
When DTC 66 is set, the transmission will have a soft landing into 3rd gear then stay in 3rd gear only. The 3-2 control solenoid resistance should be between 20-40 ohms at 20 degrees C.
Refer to "Intermittents" in Section Intermittents SYMPTOMS in this Volume.

 

[seq4x4]

DTC 67:
TORQUE CONVERTER CLUTCH "ON-OFF" CIRCUIT FAULT

The Torque Converter Clutch (TCC) "ON-OFF" solenoid is a normally open exhaust valve. The PCM activates the solenoid by earthing circuit 422 with an internal quad-driver. When the solenoid is energised it blocks the fluid from exhausting the TCC circuit and the TCC is applied.
The PCM continually monitors voltage on the TCC circuit connected to the "quad driver" for either low or high voltage depending on the commanded state of the torque converter clutch. Diagnostic Trouble Code (DTC) 67 will set if there is a fault detected on the TCC solenoid circuit. For example, if the TCC were "OFF," but voltage on the TCC circuit drops as if the solenoid were applied, then DTC 67 will be set. If the TCC were "ON" but voltage on the TCC circuit remains high (about 12 volts), as if TCC solenoid were not applied, then DTC 67 will be set.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. Diagnostic Trouble Code 67 will set if:
TCC signal circuit 422 is open or shorted to earth for 2 seconds.
This test checks to identify if the TCC circuit is currently open or shorted to earth.
3. This test checks for a short to voltage on circuit 422.
4. This test checks for resistance in the TCC solenoid and internal transmission harness.
5. This test checks for power to the Torque Converter Clutch (TCC) solenoid.
6. This test verifies that circuit 422 is not shorted to earth.
7. This test verifies that circuit 422 is not open.

Diagnostic Aids:
Be sure to check all connections especially those at the transmission pass-thru connector.
TCC solenoid resistance should be 20-40 ohms minimum when measured at 20 degrees C. Maximum solenoid current flow should not exceed 1.5 amps.
DTC 67 will only find an electrical fault with the torque converter clutch. DTC 69 will diagnosis mechanical faults with the torque converter clutch. Some slight TCC slip is normal. When diagnostic trouble Code 67 is set, the transmission will have no TCC and no 4th gear, if in the hot mode.

DTC 69:
TORQUE CONVERTER CLUTCH "ON-OFF" CIRCUIT FAULT

The Torque Converter Clutch (TCC) "ON-OFF" solenoid is a normally open exhaust valve. The PCM activates the solenoid by earthing circuit 422 with an internal quad-driver. When the solenoid is energised it blocks the fluid from exhausting the TCC circuit and the TCC is applied.
The PCM continually monitors voltage on the TCC circuit connected to the "quad driver" for either low or high voltage depending on the commanded state of the torque converter clutch. Diagnostic Trouble Code (DTC) 67 will set if there is a fault detected on the TCC solenoid circuit. For example, if the TCC were "OFF," but voltage on the TCC circuit drops as if the solenoid were applied, then DTC 67 will be set. If the TCC were "ON" but voltage on the TCC circuit remains high (about 12 volts), as if TCC solenoid were not applied, then DTC 67 will be set.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. Diagnostic Trouble Code 67 will set if:
TCC signal circuit 422 is open or shorted to earth for 2 seconds.
This test checks to identify if the TCC circuit is currently open or shorted to earth.
3. This test checks for a short to voltage on circuit 422.
4. This test checks for resistance in the TCC solenoid and internal transmission harness.
5. This test checks for power to the Torque Converter Clutch (TCC) solenoid.
6. This test verifies that circuit 422 is not shorted to earth.
7. This test verifies that circuit 422 is not open.

Diagnostic Aids:
Be sure to check all connections especially those at the transmission pass-thru connector.
TCC solenoid resistance should be 20-40 ohms minimum when measured at 20 degrees C. Maximum solenoid current flow should not exceed 1.5 amps.
DTC 67 will only find an electrical fault with the torque converter clutch. DTC 69 will diagnosis mechanical faults with the torque converter clutch. Some slight TCC slip is normal. When diagnostic trouble Code 67 is set, the transmission will have no TCC and no 4th gear, if in the hot mode.

DTC 72:
VEHICLE SPEED SIGNAL INTERMITTENT

The Vehicle Speed Sensor (VSS) circuit consists of a magnetic induction type sensor and vehicle speed sensor wiring. Gear teeth pressed on the output shaft of the transmission induce an alternating current in the vehicle speed sensor. This alternating current is transmitted to the PCM.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.

2. Diagnostic Trouble Code 72 will set if:
Two successive speed readings have a difference of more than 1000 RPM in any drive range (difference must be more than 2048 RPM in park or neutral).
This test checks the vehicle speed sensor signal to the PCM.
3. This test checks the vehicle speed sensor signal to the powertrain control module.

Diagnostic Aids:
DTC 72 is used to detect an intermittent failure. If a hard VSS fault exists, it will set DTC 24.
DTC 72 will set if the vehicle is operating at a road speed and something happens to the VSS signal.
Check all connections for proper retention. When Diagnostic Trouble Code 72 is set, the transmission will have maximum line pressure and command 3rd gear only. If DTC 72 is set while in 4th gear, the vehicle will stay in 4th gear. However, as the vehicle is coasting to stop the transmission will downshift normally from 4 to 3. Once the downshift into 3rd gear has occurred, the vehicle will stay in 3rd gear.

Check that wiring harness for VSS are not routed near high voltage sources such as spark plug cables which could induce a false signal onto the VSS signal.
DTC 72 could possibly be set by rapidly accelerating the vehicle in a loose material (such as sand or gravel) where the wheels can be spinning faster than actual vehicle speed then having the spinning wheel rapidly decrease when it contacts a hard surface. Review DTC history to identify when DTC 72 was set.

DTC 73:
PRESSURE CONTROL SOLENOID (CURRENT ERROR)

The pressure control solenoid is a PCM controlled device used to regulate transmission fluid line pressure. The PCM looks at TP sensor voltage, engine RPM and other inputs to determine the line pressure appropriate for a given load, then regulates the pressure by applying a varying amperage to the pressure control solenoid. The applied amperage can vary from 0.1 to 1.1 amp. The PCM then monitors the amperage at the pressure control solenoid low line and if the low line amperage varies more than 0.16 amp from the commanded amperage for a duration of about 1 second, Diagnostic Trouble Code (DTC) 73 is set. Once DTC 73 is set, the pressure control solenoid is disabled and full line pressure will be applied until the next time the ignition key is cycled. If upon restart, the current error does not exist, DTC 73 will remain stored but the pressure control solenoid will resume normal function.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.
2. This procedure verifies an amperage difference of more than 0.16 amp between the actual pressure control solenoid current and the desired pressure control solenoid current, the PCM's ability to control amperage to the pressure control solenoid.
3. This part of the test checks the pressure control solenoid for internal shorts and integrity.

Diagnostic Aids:
Check for poor connections at PCM and especially at the transmission pass-thru connector.
Pressure control solenoid resistance should be between 3.5-4.8 ohms at 20 degrees C.
When Diagnostic Trouble Code 73 is set, the transmission will have harsh shifts and maximum line pressure.
The PCM controls the pressure control solenoid by commanding current between 0 and 1.1 amps. 1.1 amps corresponds to minimum line pressure, and 0 amps is maximum line pressure (if solenoid loses power, transmission will still have maximum line pressure).

DTC 75:
SYSTEM VOLTAGE LOW

Diagnostic Trouble Code (DTC) 75 will set when the ignition is "ON" and PCM terminal "A4" voltage is less than 8.6 volts for about 4 seconds. Minimum voltage allowed for Diagnostic Trouble Code 75 to set is on a graduated scale and will change with temperature. Minimum voltage at - 40 degrees C is 7.3 volts, minimum voltage at 152 degrees C is 11.4 volts, 8.6 volts is the minimum voltage at 90 degrees C.
During the time the failure is present: the pressure control solenoid is turned "OFF," maintaining 3rd gear only, and inhibiting 4th gear and TCC operation and line pressure will be at its maximum.

Test Description: Number(s) below refer to step(s) on the diagnostic chart.

2. Normal battery voltage is between 9.6 - 14.5 volts.
3. Checks to see if the low voltage reading is due to the generator, circuit 39 or PCM, with engine running check voltage at the battery. If the voltage is below 8.6 volts, the PCM is OK.

Diagnostic Aids:
If Diagnostic Trouble Code 75 sets when an accessory is operated, check for poor connections or excessive current draw.
When Diagnostic Trouble Code 75 is set, the transmission will have no TCC, high line pressure and third gear only.

DTC 76:
SHORT TERM FUEL TRIM (STFT) DELTA HIGH

The PCM controls left to right cylinder bank fuel delivery separately based on their respective oxygen sensor signals. If the PCM detects too great a difference between the left to right cylinder bank Short Term (ST) Fuel Trim values, it will set DTC 76.
DTC 76 will set when the left bank Short Term Fuel Trim value differs from the right bank Short Term Fuel Trim by more than 63% for 32 seconds while in closed loop.
With a current DTC 76 set, the PCM will not illuminate the MIL (Check Powertrain Lamp). DTC 76 will clear when the fault no longer exists and the ignition switch is cycled "OFF" and "ON".

Test Description: Number(s) below refer to step number(s) on the diagnostic table.

2. Check and repair other DTC(s) first
3. Checking for other mechanical problems causing DTC to set.
4. The bank that is the farthest from the neutral value of 0% is the bank which is out of fuel control.

Diagnostic Aids:
Lean or faulty injector(s) on one side of the engine.
Cracked or fouled spark plug(s).
Exhaust or inlet manifold leak.
Make sure oxygen sensor leads are not swapped.

DTC 78:
LONG TERM FUEL TRIM (LTFT) DELTA HIGH

The PCM controls left to right cylinder bank fuel delivery separately based on their respective oxygen sensor signals. If the PCM detects too great a difference between the left to right cylinder bank Long Term Fuel Trim values, it will set DTC 78.
DTC 78 will set when the left bank Long Term Fuel Trim value differs from the right bank Long Term Fuel Trim by more than 59% for 32 seconds while in closed loop.
With a current DTC 78 set, the PCM will not illuminate the MIL (Check Powertrain Lamp). DTC 78 will clear when the fault no longer exists and the ignition switch is cycled "OFF" and "ON".

Test Description: Number(s) below refer to step number(s) on the diagnostic table.

2. Check and repair other DTC(s) first.
3. Checking for other mechanical problems causing DTC to set.
4. The bank that is the farthest from the neutral value of 0% is the bank which is out of fuel control.

Diagnostic Aids:
Lean or faulty injector(s) on one side of the engine.
Cracked or fouled spark plug(s).
Exhaust or inlet manifold leak.
Make sure oxygen sensor leads are not swapped.

DTC 81:
2-3 SHIFT SOLENOID "B" CIRCUIT FAULT

The PCM continually monitors voltage on each circuit connected to the "quad driver" module looking for either low or high voltage depending on the commanded state of the devices connected to it. Diagnostic Trouble Code 81 will set if there is a fault detected on the 2-3 shift solenoid "B" circuit. For example, if 2-3 shift solenoid "B" is commanded "ON" by the PCM, then voltage on that circuit should drop when the solenoid is earthed, if the voltage remains high for at least 2 seconds after the "ON" command is given, then Diagnostic Trouble Code 81 will be set. The opposite is also true if 2-3 shift solenoid "B" is "OFF" then the voltage on the circuit should remain high, if voltage drops for more than 2 seconds, then Diagnostic Trouble Code 81 will be set.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.
2. This test checks the PCM's ability to provide a earth for control of 2-3 shift solenoid "B".
3. This procedure checks 2-3 shift solenoid "B" and the transmission internal wiring harness for shorts.
4. This test checks for power to the 2-3 shift solenoid "B" from the ignition through the Fuse F12.
5. This test verifies that circuit 1223 is not shorted to earth.
6. The final test verifies that circuit 1223 is not open.

Diagnostic Aids:
Check all connections especially those at the transmission pass-thru connector. 2-3 shift solenoid "B" resistance should measure 20-40 ohms minimum when measured at 20 degrees C.
2-3 shift solenoid "B" current flow should not exceed 0.75 amps.
The shift solenoid should energise at a voltage of 7.5 volts or more (measured across the terminals). The shift solenoid should de-energise when voltage is one volt or less.
When Diagnostic Trouble Code 81 is set, the transmission will have no TCC, high line pressure and second or third gear only depending upon when the fault occurred.

If both solenoids lose power, third gear only will result, unless manual 2nd gear is selected.

DTC 82:
1-2 SHIFT SOLENOID "A" CIRCUIT FAULT

The PCM continually monitors voltage on each circuit connected to the "quad driver" module looking for either low or high voltage depending on the commanded state of the devices connected to it. Diagnostic Trouble Code 82 will set if there is a fault detected on the 1-2 shift solenoid "A" circuit. For example, if 1-2 shift solenoid "A" is commanded "ON" by the PCM, then voltage on that circuit should drop when the solenoid is earthed, if the voltage remains high for at least 2 seconds after the "ON" command is given, then Diagnostic Trouble Code 82 will be set. The opposite is also true if 1-2 shift solenoid "A" is "OFF" then the voltage on the circuit should remain high, if voltage drops for more than 2 seconds, then Diagnostic Trouble Code 82 will be set.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.
2. This test checks the PCM's ability to provide a earth for control of 1-2 shift solenoid "A".
3. This procedure checks 1-2 shift solenoid "A" and the transmission internal wiring harness for shorts.
4. This test checks for power to the 1-2 shift solenoid "A" from the ignition through the Fuse F12.
5. This test verifies that circuit 1222 is not shorted to earth.
6. The final test verifies that circuit 1222 is not open.

Diagnostic Aids:
Check all connections especially those at the transmission pass-thru connector. 1-2 shift solenoid "A" resistance should measure 20-40 ohms minimum when measured at 20 degrees C.
1-2 shift solenoid "A" current flow should not exceed 0.75 amps.
The shift solenoid should energise at a voltage of 7.5 volts or more (measured across the terminals). The shift solenoid should de-energise when voltage is one volt or less.
When Diagnostic Trouble Code 82 is set, the transmission will have no TCC, maximum line pressure and second or third gear only depending upon when the fault occurred.

If both solenoids lose power, third gear only will result, unless manual 2nd gear is selected.

DTC 83:
TORQUE CONVERTER CLUTCH (TCC) SOLENOID "PWM" CIRCUIT FAULT

The TCC" PWM" solenoid is used in combination with the TCC "ON - OFF" solenoid to regulate fluid to the torque converter, and is attached to the control valve body within the transmission. The Powertrain Control Module (PCM)supplies a earth allowing current to flow through the solenoid coil according to the duty cycle (percentage of "ON" and "OFF" time). This current flow through the solenoid coil creates a magnetic field that magnetises the solenoid core. The magnetised core attracts the checkball to seat against spring pressure. When the checkball is seated, it essentially changes actuator feed limit (AFL) fluid to converter clutch signal (CC SIGNAL) fluid, that is directed to the base of the Isolator Valve. Depending on the PCM controlled duty cycle, the TCC PWM solenoid determines the value of the CC SIGNAL fluid pressure.

By having an electronically controllable, variable fluid pressure acting on the end of the Isolator Valve, the force controlling the position of the Regulated Apply (REG APPLY) Valve is also variable.
This means that the Regulated Apply Valve can now vary the regulated apply (REG AP) fluid pressure that is directed to the Converter Clutch Valve.
The use of the Torque Converter Clutch Pulse Width Modulated, (TCC PWM) solenoid provides the ability of being able to control more precisely, the rate of Torque Converter Clutch (TCC) apply and release.

Test Description: Number(s) below refer to step number(s) on the diagnostic table.
2. DTC 83 will set if:
The PCM commands the solenoid "ON" and voltage remains high (B+).
or
The PCM commands the solenoid "OFF" and voltage remains low (zero volts).
All conditions met for 4 seconds.
This test will check if the PCM is commanding the TCC "PWM" solenoid "ON".
4. This test will check for voltage to the TCC "PWM" solenoid.

Diagnostic Aids:
Check all connections at the transmission pass-thru connector.
When DTC 83 is set, the PCM will inhibit TCC operation and 4th gear if in hot mode.
Under light throttle with the vehicle in gear, the TCC "PWM" will go from 0% to 90% in anticipation of applying the TCC when 3rd gear is achieved.

DTC 92:
LOW SPEED FAN NO BCM RESPONSE

The PCM determines operation of the two speed engine cooling fan based on A/C request signal input, engine coolant temperature and vehicle speed.
The engine cooling fan low speed relay (labelled LO FAN in relay housing) is energised by the BCM. When the PCM determines that the engine cooling fan low speed relay should be turned "ON", the PCM will send a message on circuit 1221 to the BCM. This message will ask the BCM to earth circuit 473 and energise the engine cooling fan low speed relay. After the BCM provides the earth for circuit 473, the BCM will send a message back to the PCM saying that the earth circuit was commanded. The DTC 92 will set if the PCM sends out the message to the BCM to turn "ON" the engine cooling fan low speed relay and the BCM does NOT send a message back to the PCM.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.
3. An open or short to earth on circuit 1221 will disable any communication of serial data between the PCM and BCM.

Diagnostic Aids:
Dirty, Damaged, or Loose Connections or Damaged Harness - Check for any damage to the harness which could cause an intermittent open or short to earth or backed out terminals at the BCM module connectors, broken locks, improperly formed or damaged terminals.
The engine will not start if circuit 1221 is open or earthed, therefore if DTC 92 is set and the engine will start, DTC 92 is intermittent. Review DTC history data to determine when DTC 92 set.

DTC 93:
SNEF CIRCUIT FAULT

The Knock sensor is used to detect engine detonation, and the PCM will retard the Electronic Spark Timing (EST) based on the signal being received The Knock sensor produces an AC signal which varies in signal amplitude and frequency depending upon the amount of Knock being experienced.
The PCM monitors the output of the SNEF (Signal To Noise Enhancement Filter) circuit. The PCM determines wether Knock is occurring by comparing the Knock sensor signal level with the voltage level on the SNEF circuit. The SNEF circuit allows the PCM to reject only false Knock signals by indicating the amount of normal engine mechanical noise present. Normal engine noise varies depending on engine speed and load. A normal Knock condition could result in a Knock sensor signal from a few milliseconds to possibly as high as 100 milliseconds in length.

When the SNEF circuit output is significantly longer than the longest expected "Normal" output it is assumed the SNEF circuitry has failed and DTC 93 will set.
DTC 93 will set if:
Engine has been running longer then 10 seconds
SNEF circuit indicates Knocking condition for greater than 10 seconds

Test Description: Number(s) below refer to step number(s) on the diagnostic chart.
2. This step checks to see if the Tech 1 "Scan" tool is displaying Knock signal at all times.
3. This step checks to see if a audible Knock is being caused by the engine or transmission.

DTC 94:
NO VEHICLE SPEED SIGNAL (MANUAL TRANSMISSION)

The Vehicle Speed Sender (VSS) has a 10-pole magnet rotated by the transmission output shaft. Attached to the sender is a Hall Effect circuit that interacts with the magnetic field created by the rotating magnet.
A 12 volt operating supply for the speed sender Hall circuit is supplied from fuse #12. An 8 volt signal voltage pulsed by the speed sender is supplied by the speedometer. This 8 volt signal is pulsed to earth 10 times per sender revolution, and is used by the speedometer, PCM, BCM and trip computer.

The VSS pulses to earth the 12 volt signal voltage sent from the PCM on circuit 123. The PCM interprets vehicle speed by the number of pulses to earth per second on circuit 123.
DTC 94 will set if no DTC 19, 21, 22, or 32 is active, and all following conditions are met for at least 4 seconds:
Circuit 123 voltage is constant - that is, NOT pulsing, and
Engine RPM between 1400 and 3000 RPM, and*
Throttle is closed < 1% (TP sensor), and*
Engine load very low (MAF sensor) 95 mg/cyl.*

*For these 3 conditions to happen during the same 4-second period of time, and in-gear, closed-throttle deceleration from road speed must occur.

DTC 97:

CANISTER PURGE CIRCUIT FAULT

Quad Driver Modules (QDMs) are used by the PCM to turn "ON" many of the current-driven devices that are needed to control various engine and transmission functions. Each QDM is capable of controlling up to 4 separate outputs by applying earth to the device which the PCM is commanding "ON".
The Quad Driver Modules (QDMs) used has the capability of diagnosing each output circuit individually. DTC 97 set indicates an improper voltage level has been detected on the QDM fault line, which controls the Canister Purge Solenoid.

DTC 97 will set if:
Ignition "ON".
The QDM fault line has detected an improper voltage level on the Canister Purge Solenoid driver
When DTC 97 sets, the PCM will not illuminate the MIL (Check Powertrain Lamp) the first time the fault is detected and the PCM will store conditions which were present when the DTC set in DTC History Data.
DTC 97 will clear when:
The diagnostic test has been run and the fault is no longer present, OR After 50 consecutive ignition cycles have occurred without a fault, OR DTC 97 can be cleared by using the Tech 1 "Scan" tool.

Test Description: Number(s) below refer to step number(s) on the diagnostic chart:
2. Normally, ignition feed voltage present on the output driver circuit with the PCM disconnected and the ignition "ON".
3. Checks for a shorted component or a short to B+ or the Quad driver circuit. Either condition would result in a measured current of over 1.5 amps. Also checks for a component that is going open while being operated, resulting in a measured current of 0 amps.
4. Checks for a faulty Canister Purge Solenoid.

 

[RX25SE]

Solid post.

Maybe the mods could sticky this?

 

[seq4x4]

Cheers mate. Ill get started on the V8 one soon.

 

[skappascrap]

Regarding Code 32, where it says Test Description: Number(s) below refer to step(s) on the diagnostic chart.
Would someone be able to put up that particular chart?

 

[BlackVXGTS]

Code 12 doesn't mean System (OK). It means that the engine is stopped:

"With the ignition "ON", engine stopped and diagnostic "test" terminal earthed, the "Check Powertrain" lamp should flash a DTC 12, followed by any diagnostic trouble code(s) stored in memory."

 

[Immortality]

I'm going to sticky this as the original lists seem to be missing atm.

And I've added a link to the original how to check engine error codes thread.

 

[Habib22]

Hi,
Can anyone please explain what i need to change in following picture code error....?

 

[theburna57]

we had about 10 error codes and the orange light remained on. The plug in the back of the airbox wasn't seated. Always check everything is plugged in