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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29427
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I have an old 98 5 speed 2.2 L Chevy cavalier. Every time I

Customer Question

Hi, I have an old 98 5 speed 2.2 L Chevy cavalier. Every time I start the heifer it runs for 2-3 seconds then the antitheft system shuts it down and th light blinks. I was able to get ahold of a tech 2 scanner and it says it's a code P1629 which is the anti theft ignition crank malfunction. I have tried every relevant process I could find with no success. Idk the finer details of a tech 2 scanner so I'm not sure if I can fix it or not
Submitted: 1 year ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 1 year ago.

Hello there, I am Cam. Sorry to hear about this issue. Can I get your first name please?

With your Car, have you tried a theft relearn? Having the scanner helps and we will try to use it, but for now, lets start with a theft relearn.

Turn the key on and attempt to start the car, It may crank, it may start and stall or it may do nothing at all, this is fine, still cycle the key to start then release the key back to run.
Wait 10 minutes with the key in run. The passlock light should be flashing and the DIC will say "Service Vehicle" or "Security" or have a picture of a car with a lock during that 10 minute span.
After 10 minutes has passed, turn off the car, count to 10, and try to start it again and release the key back to run.
Wait another 10 minutes.
After 10 minutes, turn car off 10 seconds and try to start again and release the key to run.
Wait another 10 minutes.
After 10 minutes, turn car off 10 seconds and try to start again.
It should start up this time. The passlock has been learned.

During this process, turn the fans off, radio off and cycle the headlights off so the battery will not go dead. If needed, use a battery charger.

Can you run through this and let me know what you find?

Customer: replied 1 year ago.
Ran through the whole process and got no change at all.
Expert:  GM Tech (Cam) replied 1 year ago.

Ok, then we may have a bad ignition cylinder housing. It has a sensor in it that measures the rotation of the cylinder to determine its actually rotating. When it fails or the connections to it, this is the result.

Customer: replied 1 year ago.
I should recheck all the wiring or get a new housing?
Expert:  GM Tech (Cam) replied 1 year ago.

Check the wiring, use dielectric grease on the connector and if no change, replace the housing and do the relearn again .

Customer: replied 1 year ago.
Would I have to purchase a brand new housing? Or are they interchangeable off of similar vehicles?
Expert:  GM Tech (Cam) replied 1 year ago.

Interchangeable between vehicles, but know that the replacement may not have much of a life itself. Consider new if the car is still in good shape.

Customer: replied 1 year ago.
Tried this and didn't work.all connections are sound but after trying the 30 min relaearn it still locks itself up
Expert:  GM Tech (Cam) replied 1 year ago.

I fear its the security module then, the Body Control Module (BCM) that has failed.