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JOHN aka Eauto
JOHN aka Eauto, The Car Guy
Category: Chevy
Satisfied Customers: 15076
Experience:  ase tech
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1999 Chevrolet Cavalier - Passlock issue - Key broke off in

Customer Question

1999 Chevrolet Cavalier - Passlock issue - Key broke off in ignition cylinder and car would not start. Replaced ignition cylinder with new one. Attempted the relearn procedure. Did not work after the first 10 minutes. Proceeded to do the 30 minute relearn procedure but after the first 10 minutes of the thirty minute procedure, it started, so we assumed it was fixed, and backed it out of the shop. However, it is once again starting and shutting off immediately. We attempted the relearn procedure but it is not accepting the relearn. We turn the key to the on position, crank and let off, engine starts and stops, waits full 10 minutes, then turn the switch to off, wait 20 seconds, then turn the switch back to on position, then crank it, and it will start and stall, and continue to do that. But, we've noticed the Theft light only flashes about 7 times, and then quits flashing, instead of continuing to flash for the 10 minutes of the relearn procedure. What is going on with this stupid car? We are getting a p1629c code that reads Anti-Theft device cranking signal
Submitted: 11 months ago.
Category: Chevy
Expert:  JOHN aka Eauto replied 11 months ago.

sometimes it takes 3 or 4 sometimes 5 relearns to get out of theft mode///

The following information was omitted from the Service Manual:

If you replace the ignition lock cylinder, the system will enter the long tamper mode. If the system enters the long tamper mode, ensure that the system completes a long tamper mode cycle. During the long tamper mode cycle, the THEFT indicator will flash for the full 10 minutes. The instrument cluster and the PCM require the full 10 minutes in order to complete the learn cycle. Ensure that the ignition switch remains in RUN until the indicator stops flashing. If you turn the ignition switch before the indicator stops flashing, ensure that you repeat the long tamper cycle from the beginning

Customer: replied 11 months ago.
That's not what happens. It only flashes 7 times and then stays on.
Expert:  JOHN aka Eauto replied 11 months ago.

and your performing a 30 minute relearn?

Expert:  JOHN aka Eauto replied 11 months ago.
  • Short Tamper Mode-Engine may start and stall quickly. THEFT SYSTEM telltale will flash on the IPC for 4 seconds.
  • Long Tamper Mode (More than three starting attempts or an invalid password ***** *****)-The engine is disabled for at least 10 minutes and the THEFT SYSTEM telltale will flash on the IPC for the 10 minutes.
Customer: replied 11 months ago.
We did the 30 minute relearn procedure 4 times at this point. After installing the lock cylinder, it started after the 10 minute relearn procedure, and then would not start again 2 hours later, doing what it did the first time.
Expert:  JOHN aka Eauto replied 11 months ago.

sometimes the relearn needs to be done repeated times... The other option is with a tech 2 or dealer laptop...

Customer: replied 11 months ago.
you don't think that it is a short in the tan wire going between the instrument cluster and the ignition switch
Expert:  JOHN aka Eauto replied 11 months ago.

I doubt it since it worked prior to switch replacement... id try a relearn a few more times before I started tracing wires from the switch to the ip

Customer: replied 11 months ago.
It did not work prior to switch replacement that's why we replace the switch
Expert:  JOHN aka Eauto replied 11 months ago.

thought you replaced the switch because the key broke?

Customer: replied 11 months ago.
The key had been broken for some time, and they continued to start the vehicle. However, when the vehicle engaged passlock, they had the vehicle towed to us. We attempted a relearn, and it would not accept it. So, we replaced the ignition switch. The subsequent relearn procedure worked, and we were able to start the vehicle and back it out of the shop. Fast forward two hours. Customer shows up to pick up vehicle. Vehicle won't start, and is back in passlock. We attempted relearn procedure, and it did not work. We tried the relearn procedure 3 more times, and no success. The theft light would blink 7 times, and then STAY ON CONSTANT. Even after waiting more than 10 minutes, the theft light never went off. Now, according to what you're saying, it's in short term theft lock. Great. But the 10 minute nor the 30 minute relearn are working. I suspected that through the wiggling of the wires when replacing the ignition switch, the tan wire that goes from the switch to the Instrument Cluster connected briefly enough to allow the passlock relearn to take place. But, I wasn't sure, so I am asking you if you think that's a possibility. I'd also like a wiring diagram of the UART system so that I can go about diagnosing the wiring problem.
Customer: replied 11 months ago.
I just got a request to rate your service. Does that mean you are finished helping me or are you opting out or what?
Expert:  JOHN aka Eauto replied 11 months ago.

no that's automated from the site ..here is your diagram

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