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[VT-VX] + [VY] How to set PCM properly after a reset

alien

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OK, because i searched and couldn't find any details and people are confused about what to do, this is the official guide (backed by Official Holden Manual).

This is for the VT to VY range of vehicles (V8's ONLY [Thanks Doctor Bob]). I'm not sure if it's the same for VZ and VE though.

Basically when you remove the PCM or disconnect the battery the PCM will forget certain things. One big thing is the IAC (Idle Air Control) valve pintle position is forgotten. This leads to an unstable idle and not the idle level that is usually stated on the vehicle placard.

So, to get the PCM to get it all good again, this is what is needed:

For AUTOMATIC transmissions:
  1. Turn OFF igntion
  2. Restore power to PCM (if needed)
  3. Turn OFF the A/C controls
  4. Set park brake and block the drive wheels
  5. Start Engine
  6. Place Transmission in D (Drive)
  7. Allow vehicle to idle for 10 minutes
  8. Turn ON the A/C controls
  9. Allow vehicle to idle for 10 minutes
  10. Place Transmission in P (Park)
  11. Allow vehicle to idle for 10 minutes
  12. Turn OFF the A/C controls
  13. Allow vehicle to idle for 10 minutes
  14. Turn OFF the engine for at least 30 seconds

For MANUAL transmissions:
  1. Turn OFF igntion
  2. Restore power to PCM (if needed)
  3. Turn OFF the A/C controls
  4. Set park brake and block the drive wheels
  5. Place transmission in Neutral
  6. Start Engine
  7. Turn ON the A/C controls
  8. Allow vehicle to idle for 10 minutes
  9. Turn OFF the A/C controls
  10. Allow vehicle to idle for 10 minutes
  11. Turn OFF the engine for at least 30 seconds

Last step for BOTH transmissions is to enjoy a beer or whatever you prefer.

Then just check how it idles for 1 minutes whenever you get in it next. Should be all good and fine.

As you can see, manual vehicles only take about half the time, but simply for the fact that the autos have a drive AND park that need the IAC set for properly. Whereas a manual only has neutral that it needs to be set for. And those states also need to be taught what it's like with A/C controls on and off.
 
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Doctor Bob

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this is valid for V8, the V6 PCM resets the IAC zero position at every ignition cycle
 

alien

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Thanks Doctor Bob, i forgot to mention that it is only for V8's. I have updated the first post now.
 
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