# Solved: 2003 Pontiac anti-theft problem?



## cwwozniak (Nov 29, 2005)

Without giving away any kind of company secrets, can somebody please explain to me how a part of GM's 2003 anti-theft systems operates?

Our daughter has been driving my old 2003 Pontiac with no starting problems for the last couple of months. She has a duplicate key that was copied from my factory original key. There are no security chips in the keys as far as I can tell. The car does not have On-Star.

The car would not start when she tried to go to work this morning. I went out with my key and could not start it either. All of the dash warning lights, daytime headlights and radio come on when the key is first put in the run position. Turning it to the start position does not get any kind of noise from the starter system (not even a relay click), the daytime headlights stay at the same brightness, and all of the dash warning lights, except for the "Check Engine" light, go off.

AAA could not get it started on our driveway and towed the car to a local repair shop (not a GM dealership). I gave them my original key.

The shop called me back about an hour later. They said the car started fine and could be driven into the service bay. They shut it off and then it would not start. The service guy said the problem was probably in the anti-theft hardware and asked me if I had another key. I dropped off a second key that was made at the same time as our daughter's key. 

They just called me back and said something about the security code in the ignition switch getting messed up. They will need to take it to a dealership on Monday for resetting or replacement.

Would either of these conditions be a cause of the problem?

1) She had the OEM stereo replaced with an after market one right after she got the car. Part of the installation included adding a combined On-Star / Chime module to replace the chime function of the OEM radio. The store didn't have a chime only module.

2) It was about 70 degrees this morning with near 100% humidity.


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## JohnWill (Oct 19, 2002)

I can't see either of those affecting the security system, but that doesn't mean it's not possible. I don't think it's likely...


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## cwwozniak (Nov 29, 2005)

Ended up replacing the lock cylinder assembly and that cured the problem.

Turns out repair shop was more concerned that the radio installer pinched a wire that may have been causing an intermittent short circuit rather than a mis-wired or failed chime module or radio.

I was asking about the temperature and humidity aspect just because I have seen some electronics assemblies temporarily malfunction if a little bit of dirt between conductors combines with a bit of condensation.


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## JohnWill (Oct 19, 2002)

Well, glad you got it sorted out.


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