Cant start my 2005 Grand Am GT

[Vegeta]

VATS probably locked out the BCM functions so you can't get into the trunk. It thinks you stole the car. Putting another computer in doesn't make it think its all good now. You have to do a relearn with the key. If you disable the VATS, then there is no security system, and most likely everything works again.

[AaronGTR]

Originally Posted by Hawkeye1980

Its not just the lights

Key fob
Radio
Door locks
trunk release

All not working.

Power windows
power moon roof
headlights

All work

I just dont get it at all. Figured the PCM was the culprit.

Not likely. The PCM doesn't control any of that. It only controls the engine and transmission, nothing else. It communicates with the the BCM though (body control module) which controls that stuff. Could be a bad BCM, or could just be a security issue between the PCM and BCM. There is a security feature where if you swap PCM's without flashing or turning off the security feature, the car won't start. This is not related to the VIN, but an actual rotating security code between the BCM and PCM. I've had this happen before when swapping PCM's, but I have a tuner so I was able to turn it off. I don't know if this would cause the other issues you are talking about though ( I don't believe it would).

[Hawkeye1980]

Originally Posted by Vegeta

VATS probably locked out the BCM functions so you can't get into the trunk. It thinks you stole the car. Putting another computer in doesn't make it think its all good now. You have to do a relearn with the key. If you disable the VATS, then there is no security system, and most likely everything works again.

thats fine, but I have not been able to re train the password to from the BCM to the PCM, or however it works. Also, i put in teh 2200 ohm resistor and that did not help either. I do want to disable the VATS ultimately but only after I figure out how, why this happened what was is the root cost.

Plus I have a spare BCM with matching numbers and that did nothing either. At best I should be able to do the 10 or 30 minute re learn procedure, which I cannot. The stupid security light never blinks, just stays solid, and never goes out. No crank, and I hear to fuel pump prime.

I have tested everything for the most part, even the starter check out.

Both the check engine and service engine lights are on. But there are no codes with my reader.

[Hawkeye1980]

Originally Posted by AaronGTR

Not likely. The PCM doesn't control any of that. It only controls the engine and transmission, nothing else. It communicates with the the BCM though (body control module) which controls that stuff. Could be a bad BCM, or could just be a security issue between the PCM and BCM. There is a security feature where if you swap PCM's without flashing or turning off the security feature, the car won't start. This is not related to the VIN, but an actual rotating security code between the BCM and PCM. I've had this happen before when swapping PCM's, but I have a tuner so I was able to turn it off. I don't know if this would cause the other issues you are talking about though ( I don't believe it would).

Thats the crux of the issue. Why are other features turned off? Its odd I cant find anyone else having the same issue.

Something burned out, is my best guess. What it is, I dont know.

[Vegeta]

You want your car to run but not until you know why and how it doesn't run?

[Hawkeye1980]

Originally Posted by Vegeta

You want your car to run but not until you know why and how it doesn't run?

It doesnt run at all, it wont even crank. The fuel pump prime and nothing, no click, nothing.

I spoke with the supplier of the replacement PCM. he is saying it could be ground. That me using a replacement BCM with matching VAT number doesnt matter.

The bottom line is the stupid security light wont go off at all. No matter what I do.

I just cant believe I am the only person it seams who has this problem.

Is there a way to reprogram the BCM so it matches my PCM? What I am reading now, I am back to thinking I burned out my original BCM and need to somehow match a replacement to the PCM. If so what device will let me do this? What device can I use to KILL the VATS once and for all?

I just dont want to spend any more money until this is fixed normally. D@mn this GM VATS garbage.

[Hawkeye1980]

Originally Posted by AaronGTR

Not likely. The PCM doesn't control any of that. It only controls the engine and transmission, nothing else. It communicates with the the BCM though (body control module) which controls that stuff. Could be a bad BCM, or could just be a security issue between the PCM and BCM. There is a security feature where if you swap PCM's without flashing or turning off the security feature, the car won't start. This is not related to the VIN, but an actual rotating security code between the BCM and PCM. I've had this happen before when swapping PCM's, but I have a tuner so I was able to turn it off. I don't know if this would cause the other issues you are talking about though ( I don't believe it would).

what tuner do you have?

[Hawkeye1980]

have a look at this:

https://www.ebay.com/itm/FlashLogic-...4383.l4275.c10

[Hawkeye1980]

one more thing. I have not pulled the battery from my FOB, should I do that??

[Vegeta]

For $400 you can get hptuners and the credits you need to disable the vats.

[Madness10]

Originally Posted by Hawkeye1980

have a look at this:

https://www.ebay.com/itm/FlashLogic-...4383.l4275.c10

That is only for bypassing when you have an aftermarket alarm. Will do you no good in your case.

[Hawkeye1980]

Originally Posted by Madness10

That is only for bypassing when you have an aftermarket alarm. Will do you no good in your case.

too much for me. My back is up against the wall it seams. Wish I could find a decent repair place where I live. most of them are not that smart or charge to much.

[Vegeta]

Wouldn't it be cool if you tried deleting the VATS and it worked?

[Hawkeye1980]

Originally Posted by Vegeta

Wouldn't it be cool if you tried deleting the VATS and it worked?

yes it would. But how can I be sure it will work? Forgive me, but after all I have done I wonder now if that will even work.

[Hawkeye1980]

Originally Posted by Vegeta

Wouldn't it be cool if you tried deleting the VATS and it worked?

I have 2 PCMs, which one would I send to you? Original or the replacement one I just got?

[Vegeta]

Originally Posted by Hawkeye1980

I have 2 PCMs, which one would I send to you? Original or the replacement one I just got?

It shouldn't matter but send the replacement if its the same SERV# as your original.

[Hawkeye1980]

Originally Posted by Vegeta

It shouldn't matter but send the replacement if its the same SERV# as your original.

PM sent

[Hawkeye1980]

Originally Posted by Vegeta

It shouldn't matter but send the replacement if its the same SERV# as your original.

Ben sent you a PM.

[Madness10]

Any updates?

[Hawkeye1980]

Originally Posted by Madness10

Any updates?

Well, I sent my original PCM to Ben. The post office lost it, for about 3 weeks.\

after bugging them almost daily after opening a tracking ticket, it got to Ben. Ben sent it out about 4 days later and it arrived yesterday....

All I can say is.... THANK YOU BEN!!!!! IT STARTED RIGHT UP!!!

what a nightmare this car has been. But I cannot and I mean this to everyone who responded... THANK ALL OF YOU SO VERY MUCH. I would buy you all a cold one if I could.

Only issue left:
No radio
No internal overhead lights or review mirror lights
No door locks
no truck release.

May be some other things as well. Power windows work, wipers work, turn and emergency lights ok. Headlights work.

Also need to kill the security light, its still on solid. But the car RUNS!!!