Cant start my 2005 Grand Am GT

[Hawkeye1980]

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[Hawkeye1980]

OK where is the PCM on this car please? I have looked in the car and engine compartment. Unbelievably there are no pics or videos to show where its located anywhere on the internet. This is nuts. Thanks.

[Vegeta]

I could only see if it can read and write. If an injector driver was bad, I wouldn't know. Just an example. The computer is located under the driver side dash, against the fender area.

[Madness10]

Originally Posted by Hawkeye1980

I guess. If I sent you my original could you tell if it is bad? I just dont want to spend money a bad PCM to remove the VATS.

Otherwise I will see if I can find one that you could flash and remove VATS.

What is the SERV# on your pcm. I am going to have one coming out of a 2004 that might work that I can sell you.

[nivek98]

Originally Posted by Hawkeye1980

OK where is the PCM on this car please? I have looked in the car and engine compartment. Unbelievably there are no pics or videos to show where its located anywhere on the internet. This is nuts. Thanks.

Under dash drivers side...

https://www.justanswer.com/pontiac/2...ated-1999.html

[Hawkeye1980]

Originally Posted by Madness10

What is the SERV# on your pcm. I am going to have one coming out of a 2004 that might work that I can sell you.

I actually got my hands on one cheap on eBay. Going to plug it in and see if it fixes all the other issues, door locks, etc. At this point I think my PCM is bad.

The seller is programing it to my VIN. Thanks man!

[Hawkeye1980]

Originally Posted by nivek98

under dash drivers side...

https://www.justanswer.com/pontiac/2...ated-1999.html

thank you !

[Hawkeye1980]

Originally Posted by Vegeta

I could only see if it can read and write. If an injector driver was bad, I wouldn't know. Just an example. The computer is located under the driver side dash, against the fender area.

Well I got my hands on one from eBay and it will be coded to my VIN. I am hoping this will get the car going. If so then I will look at your service to get the stupid VATS disabled.

[sugar ray]

I may be able to assist here!
You mentioned after market radio?

I have a 2002 SE 3.4 (original owner) and went through your exact head ache. Fortunately I didn’t have to battle long to find it. About 7 years back I removed the STOCK monsoon radio/CD deck for a fancy touch screen. I was NOT a fan of having to hack into the stock harness so I purchased a very expensive GMOS-04 module. It allows you to plug and play your aftermarket stereo deck without hacking your harness and you still retain all factory chimes and onstar if so equipped. It also retains the factory amp.

Anyways....after 2 years of use one day I go to get into my Grand Am and went to start it.
NOTHING! Solid security light! Turn key no crank. Some accessories work others won’t?

GM got too fancy with these cars. The DATA BUSS is tied into the radio harness!
In my case.....my first GMOS-04 Stereo adapter had failed. The data buss tying into the now failed stereo circuit was preventing anything from working.

I simply took the trim plate around the radio out. Disconnected the stock stereo harness that went into the aftermarket GMOS-04 Wire block. Turned the key to ON and
The security light had disappeared, the car started, and everything ran Normal!

I put the stock monsoon CD deck back in for tunes. I then ordered replacement GMOS-04 module so I could go back to my aftermarket stereo. I’ve had the replacement module over 5 years and it’s been good ever since

I’m NOT saying this will be your problem but it sure sounded like mine!
Sadly the databuss is within the stereo wiring.
You’ve got nothing to lose

Give that a shot

[Hawkeye1980]

Originally Posted by sugar ray

I may be able to assist here!
You mentioned after market radio?

I have a 2002 SE 3.4 (original owner) and went through your exact head ache. Fortunately I didn’t have to battle long to find it. About 7 years back I removed the STOCK monsoon radio/CD deck for a fancy touch screen. I was NOT a fan of having to hack into the stock harness so I purchased a very expensive GMOS-04 module. It allows you to plug and play your aftermarket stereo deck without hacking your harness and you still retain all factory chimes and onstar if so equipped. It also retains the factory amp.

Anyways....after 2 years of use one day I go to get into my Grand Am and went to start it.
NOTHING! Solid security light! Turn key no crank. Some accessories work others won’t?

GM got too fancy with these cars. The DATA BUSS is tied into the radio harness!
In my case.....my first GMOS-04 Stereo adapter had failed. The data buss tying into the now failed stereo circuit was preventing anything from working.

I simply took the trim plate around the radio out. Disconnected the stock stereo harness that went into the aftermarket GMOS-04 Wire block. Turned the key to ON and
The security light had disappeared, the car started, and everything ran Normal!

I put the stock monsoon CD deck back in for tunes. I then ordered replacement GMOS-04 module so I could go back to my aftermarket stereo. I’ve had the replacement module over 5 years and it’s been good ever since

I’m NOT saying this will be your problem but it sure sounded like mine!
Sadly the databuss is within the stereo wiring.
You’ve got nothing to lose

Give that a shot

you know, there has been this little voice in my head about the radio. I too have the same setup as you do. I remembered putting in something with the aftermarket radio and couldnt remember what it was. Did this several years ago as well.

I am going to try this later today and update. thank you!!

[Hawkeye1980]

oh well, pulled all the radio equip out along with the GMOS-04, same thing, NO START, solid security. I really loathe the folks who designed this security system! I cant even start my own D@MN car.

My last hope is the replacement PCM. Will be in this week. Otherwise maybe I will just torch this junk.

[sugar ray]

That’s unreal!!
You must have accidentally fried something when jump started?
Sure hope your new PCM solves the issue! What a piss off, most may have walked away a long time ago

[Hawkeye1980]

Originally Posted by sugar ray

That’s unreal!!
You must have accidentally fried something when jump started?
Sure hope your new PCM solves the issue! What a piss off, most may have walked away a long time ago

At this point that's all I have left. Very frustrating indeed. I hope the replacement PCM works as well. Will update when done. thanks for the help!

[Hawkeye1980]

well the replacement PCM came in today, and of course didn't fix anything.

At this point I have just about given up. I just don't get it.

[Vegeta]

Did they delete the VATS?

[Hawkeye1980]

Originally Posted by Vegeta

Did they delete the VATS?

no they didn't offer that service. It doesn't matter at this point. Something else is going on. Why are several electrical items not working as well. cant seem to find that answer.

Extremely aggravating.

[Vegeta]

Originally Posted by Vegeta

If it cranks over, then flashing the computer to disable VATS might be the easiest fix.

Good luck.

[Hawkeye1980]

Originally Posted by Vegeta

Good luck.

appreciate the well wishes but all I have left is a GM dealership at this point. I cant believe there are no articles on why some car features that are dont work are available.

[T50]

Did you check EVERY fuse? with a meter to test the resistance. might look good but may be bad, could be a relay as well...

No lights inside just seems off.

[Hawkeye1980]

Originally Posted by T50

Did you check EVERY fuse? with a meter to test the resistance. might look good but may be bad, could be a relay as well...

No lights inside just seems off.

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.