Code 47 Fault

[COOLVS]

Hi all yesterday whilst rushing to hopsital with my gf
anyway after arrival of our new son i jumped in the the VS and noticed the engine light was on what the car now is not getting 1st and 4th gear and wont change from 2nd to 3rd unless done manually
done the code test and came up with code 47 which is Crank angle reference signal (no signal)
so will the CAS affect the auto some how??
the car starts fine no dramas there
noticed also yesterday when the engine light dissappeared the auto was fine (though now the light stays on all the time
any suggestions on whats happening here

cheers

[SUSVS]

Not selecting them gears sounds like gear solenoids but I don't see how the Cas has anything to do with that?

[db_notso]

if there is no engine rpm signal recieved by the ecm then it doesnt send one to the auto to calculate shift patterns
it should still change anyway due to hydraulic pressures....
suggest that maybe you need to take your car somewhere to get codes read on a propper scan tool,
as some cheaper items wont show ALLL computer codes stored...

and also if work has recently been done around the trans or motor check the wiring harness's havent been knocked loose at the plugs on the auto especially

[BlackVXGTS]

VS Service Maintenance CD says that DTC47 doesn't illuminate the "Check Powertrain" lamp. Are you sure you checked the code correctly? Suggest you reset the codes, drive the car around, and read the codes again.

18X REFERENCE SIGNAL MISSING
Circuit Description:
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”.

[greenacc]

Code 47 can be a real bastard. On my VS it always ended up being a dead or dying DFI Module.
TIP - don't by an aftermarket one, i went through 2 in 3 years.

[Brett_jjj]

I was getting error code 47 setting not long ago on my VSV6.First up I replaced the DFI module which made it run way better,but it was still getting code 47 setting every now and then.Next I bought a new crank angle sensor (CAS) from holden, ($120), and when I went to replace it,I found that whoever had fitted the old CAS before I got the car,didnt use loctite on the 2 CAS bolts and they had come loose and the CAS was moving about,luckily not enough to hit the interruptor blades at the rear of the balancer that pass through the CAS though.The workshop manual specifies using loctite or similar on the 2 CAS bolts..I fitted the new CAS with loctite on the bolts and have not had the error code come back again..Anyway Id say it was because the CAS was loose that it was setting the code 47 every now and then ,the old CAS is probably still ok,anyway ,it can be worth checking that it hasnt come loose.The CAS has to have the right air gaps from the interruptor blades on the balancer where they pass through it,the older V6's needed the gap to be set,but the later models are non adjustable,no wonder it would never seem to run 100% right.I could never track down why until I found the loose CAS..

[COOLVS]

thx for the reply guys
i did a recheck on the codes and this time 47 and 81 popped up
so now i know the 2-3 soleniod is gone or so i thought cause now the engine light is off and theres no prob with the car and gears are back to normal
must of been somethin loose there somewhere
i will check the CAS and see if its tight

[hako]

I had a code 81 with engine light and LHM...went away for a few days then back again....got sick of this and had the solenoid replaced...about $200 including a oil change and service of trans. All good since then (4 years ago)