[LS1] VZ Solve accelerator pedal position sensor issue or convert drive by wire to cable

[Fu Manchu]

I will get photos for you. Hold my beer...

 

[Fu Manchu]

Throttle body

Pedal and position sensor.

Throttle actuator control module.

 

[lmoengnr]

Ok, a separate actuator?

 

[Fu Manchu]

The TACM monitors the accelerator pedal position through the two APP sensors and forwards this signal to the PCM via
a dedicated serial data line. The PCM processes this information along with other system sensor inputs to command the
throttle plate to a certain position. This throttle position request is sent back the TACM along the same serial data line,
and the TACM sends a pulse width modulated signal to the throttle body.
A direct current motor called the throttle actuator control motor controls the throttle plate. The TACM can operate this
motor in the forward or reverse direction by controlling battery voltage and/or ground to two internal drivers. When there
is no current flowing to the actuator motor, the throttle plate is held at a rest position of 7 percent open using a constant
force return spring.
The TACM monitors the throttle plate angle through two TP sensors. Using this information, the TACM can precisely
adjust the throttle plate.
The TACM performs diagnostics that monitor the voltage levels of both APP sensors, both TP sensors and the throttle
actuator control motor circuit. It also monitors the spring return rate. These diagnostics are performed at different times
based on whether the engine is running, not running, or whether the TACM is currently in a throttle body relearn
procedure. This information is sent to the PCM for external diagnosis purposes.
Two sensors within the accelerator pedal assembly and throttle body assembly are used to provide redundancy. If a
malfunction is detected, the throttle plate is moved to a pre-determined position.
Every ignition cycle, the TACM performs a quick throttle return spring test to ensure the throttle plate can return to the 7
percent rest position from the 0 percent position. This is to ensure that the throttle plate can be brought to the rest
position in case of an actuator motor circuit failure.

 

[Jolls]

Which Gen 3 PCM drives an electronic throttle body?

The VZ Gen III is the only one that does it. The VY was cable actuated.

As outlined above the Throttle Acctuator Control Module (TACM) monitors the accelerator pedal position through the two APP sensors and forwards this signal to the PCM through a dedicated serial data line. The PCM processes this information along with other system sensor inputs to command the throttle plate to a certain position. This throttle position request is sent back the TACM along the same serial data line and the TACM sends a pulse width modulated signal to the throttle body.

The throttle actuator control motor controls the throttle plate. The TACM can operate the motor in the forward or reverse direction by controlling battery voltage and/or ground to two internal drivers. When thereis no current flowing to the actuator motor, the throttle plate is held at a rest position of 7 percent open using a constant force return spring.

The TACM monitors the throttle plate angle through two TP sensors. Using this information, the TACM can precisely adjust the throttle plate.
The TACM performs diagnostics that monitor the voltage levels of both APP sensors, both TP sensors and the throttle actuator control motor circuit. It also monitors the spring return rate. These diagnostics are performed at different times based on whether the engine is running, not running, or whether the TACM is currently in a throttle body relearn procedure.

This information is sent to the PCM for external diagnosis purposes. Two sensors within the accelerator pedal assembly and throttle body assembly are used to provide redundancy. If a malfunction is detected, the throttle plate is moved to a pre-determined position. Every ignition cycle, the TACM performs a quick throttle return spring test to ensure the throttle plate can return to the 7 percent rest position from the 0 percent position. This is to ensure that the throttle plate can be brought to the rest position in case of an actuator motor circuit failure.

So - the PCM doesn't drive the throttle body. The TACM does - the PCM interprets data from the TACM and other inputs and then signals the TACM to operate the throttle body as required.

Cheers n Beers
Jolls

 

[Jolls]

Sorry about the repeat post. There was no post showing when I added mine and then it appeared. Don't seem to be able to delete it though.

 

[Sexy_vx]

Which Gen 3 PCM drives an electronic throttle body?

Little bit of a late response but my dad just got a 04 vz ss and it’s dbw things in safety mode and trying to find some answers

 

[Fu Manchu]

Little bit of a late response but my dad just got a 04 vz ss and it’s dbw things in safety mode and trying to find some answers

That needs a new thread posted in the VZ section.
Your dad needs a high end scan tool onto the car that has bi-directional features to even start looking at the cause. Could be 100’s of things.

 

[Sexy_vx]

That needs a new thread posted in the VZ section.
Your dad needs a high end scan tool onto the car that has bi-directional features to even start looking at the cause. Could be 100’s of things.

We’ve already had it scanned and the tb is fucked and isn’t relaying any data back to the pcm about position or anything I was just saying that 04 Vzs have dbw

 

[lmoengnr]

Little bit of a late response but my dad just got a 04 vz ss and it’s dbw things in safety mode and trying to find some answers

Is it an LS1 or an L76?