Need Help 07 Chevy Tahoe Security Problem

[PGH STEELERS]

My wife's Chevy Tahoe came with a security system (I'm assuming that came from the factory) that works off of her factory key fob and at times her car won't start or she can't even use the key fob. When she goes to unlock the door with the key, the security systems turns on, but the car won't start. I can jump start the car. I took the car to Advanced Auto and the battery is good, the alternator is good and the starter is good. So, is there anyone out there that may know what's going on and can help. Yes, the warranty is out.

[bucd]

Does it do it with both key/keyfob? Maybe the one has a damaged transponder?

 

-D

[Rocky31186]

Dumb question, but have you checked the key fob battery with a volt meter?

[PGH STEELERS]

Great points and no I haven't checked out the key fob battery or the transponder. That will be the next thing to do. Someone at work asked me if the key fob got wet and I'll have to check this all out.

[BoostedAce]

Do you have the theft deterrent system option?

[Cordell]

I'm confused about your description, you mean when the key is used in the door it sounds the horn? and after that the vehicle won't start? or just sometimes it doesn't start randomly and the security light is on?

 

The best thing to do is scan the vehicle's theft deterent module for codes, but I'm not sure how to do that other then with a GM scan tool. As long as a factory key is used in the ignition the vehicle should start regardless of whether it has working fob or not.

[PGH STEELERS]

Ok, when my wife goes to hit the unlock button on the key fob, the vehicle does nothing, no sound, no lights flashing, nothing. When she goes to unlock the car door with the key, the alarm goes off. When she puts the key in the ignition, nothing happens period. Does this happen all the time, no, just once in a while, it usually happens when the temperature is around 100 degrees.

 

My friend loaned me his scanner and I checked for any type of code and I got nothing. I think I need to take her vehicle in to the dealership to get her key fob's battery replaced, and what ever else they do to it to program it?

 

I'm not sure what type of security system is on this vehicle, all I know the car came this way from the factory. Just the standard car alarm system that locks and unlocks the doors, a siren sound when you open the door with out the key. I'm not sure what systems the manufacturer installs or even if the manufacturer does this? I assume the manufacturer does these installs. I wish I knew what was going on with her car. Any help would be greatful.

[KillJoy]

The Grand Am does this.

 

The "quick" fix: Insert Key - Turn to ON (do not start) - Let it sit for 15 Mins - Remove Key - Reinsert Key and start

 

KillJoy

[bucd]

possible fix here?:

 

http://www.tahoeyukonforum.com/forum/showthread.php?t=8978

 

I don't know what exactly did the dealer do when he said that they reset the computer and it fixed the problem.

 

Maybe pulling the battery may work?

 

-D

[PGH STEELERS]

Thanks for this. I'll look at the manual to see about reprogramming (which I should have done but didn't). If not, I'll have to take it to the dealership. I can try disconnecting the battery to see if that does anything, but like one of the guys stated, it doesn't reset the bcm. Thanks guys, I appreciate this. I'll get back with results.

[PGH STEELERS]

Ok, here is the latest on this. I took my wife's car into Dan Tobin's cause this situation was getting out of control. So we take the Tahoe there, spend the $100.00 to get the Tahoe analyzed, and they can't find anything wrong. So at this point, I have changed the car battery just in case. I have not tried to reprogram the key fob as mentioned above, but I guess that is my next item to check off. I will change the battery in the key fob and go for it. I have a feeling it has something to do with the computer? I'm not sure if it needs reflashed?

 

Just to kind of back up here. When you now go to hit the key fob to unlock the Tahoe, now nothing happens. You go to unlock the door manually and no alarm sounds at all. You got to turn the key to turn the Tahoe on and nothing. Now, what I have been doing is turning the key to the on position, putting the gear shift into drive and then putting it back into park. Some how when I do this, the car will start? Really confused?