V6 Calais ECU

[_R_J_K_]

31 shouldn't affect the key not starting a car.

Yeah it will, the ECU is looking for the theft deterrent signal from the BCM but can't find it, so it won't start. It's the reason you get no-VATS memcals and why it tried to start after 2 hours, wouldn't be much of a theft deterrent if it didn't. Same thing happens when you put a VR memcal in a VS or vice versa.

OP, it can't hurt to swap the BCM over (you shouldn't need to do the ECU as they don't need to be linked) but keep in mind you'll also need to swap the key barrel too.

What trouble shooting have you done so far? Have you checked your fuses and earths? When/how did this start occurring? Does the radiator fan turn on when you try to start it?

 

[losh1971]

Mine has code 31 and has no starting issues, except the key being a bit worn and not making contact occasionally. Other than that it's starts every time. Why would mine still fire if I have 31 and always have?

 

[_R_J_K_]

Seems it can go either way. People in this thread seem to say the same as you Losh:

Code 31 - Theft Deterrent Signal missing

Hi, Ive just started getting Code 31 - Theft Deterrent Signal missing error and i havnt a clue what it means, nothing has changed in my car except it was sitting for 2 weeks without starting it and now this error has come up. Can anyone shed some light on what causes it and how to get rid...

forums.justcommodores.com.au

That thread also says that this seems to be related to the key (and a number of others say it's related to the key being dead/on the way out). OP, does it change if you unlock the car with the remote before you try to start it? Does the car lock/unlock with the remote? Can you ensure that the metal dimple on the keyhead is making good contact with the metal rings around the barrel? You may need to pry them up ever so slightly.

 

[gtrboyy]

You have mace memcal...guessing vats turned off so when you click fob it looks for signal hence fault code...still works as matching key/bcm to crank & fuel.

That's my guess although most I've seen didn't throw up fault codes with vats off despite matching key fob/bcm

Most mail order tunes will be vats off to avoid that headache...

 

[Adza]

Yeah but to even get to that stage ive got to let the immobiliser time out for 120mins.
The problem is i can’t get a fob/key to code with the current bcm.

 

[Adza]

Seems it can go either way. People in this thread seem to say the same as you Losh:

http://[URL]https://forums.justcomm...ode-31-theft-deterrent-signal-missing.141023/

[/URL]

That thread also says that this seems to be related to the key (and a number of others say it's related to the key being dead/on the way out). OP, does it change if you unlock the car with the remote before you try to start it? Does the car lock/unlock with the remote? Can you ensure that the metal dimple on the keyhead is making good contact with the metal rings around the barrel? You may need to pry them up ever so slightly.

Brand new Holden key/fob nothing unlocks remotely. Metal piece is touching also. Had a new key made with fob but it will not code. Thats why i am wondering if the bcm is stuffed in it.

 

[_R_J_K_]

How were you trying to code the key?

 

[Adza]

Had a mobile locksmith come and make a new key and holden fob. He tried then to code it to the bcm but wouldnt work. I bought the car with no key as the owner had lost it.
Also when the key is in the ignition the dash lights up but when i go to start nothing as the key isnt coded to the bcm. Only cranks after the immobiliser is timed out after 120 mins.

 

[gtrboyy]

vr/s don't take 120mins to time out it's less than an hour so that so that weird issue there.

Borrow or buy another matching memcal/bcm/keyhead

 

[Adza]

vr/s don't take 120mins to time out it's less than an hour so that so that weird issue there.

Borrow or buy another matching memcal/bcm/keyhead

Yeah ok thats the answer i wanted thanks. Didn’t realise a Calais V6 auto bcm wouldnt work in a Acclaim auto V6