How to conduct an Anti-theft system reset?

JOHN FULLILOVE

MEMBER
1999 CHEVROLET CAVALIER
2.4L
4 CYL
2WD
AUTOMATIC
150,000 MILES

I’m told that there is a fairly easy to do 30-minute reset for the theft system on my car listed above. Could you please run it down to me step by step? Thanks for your assistance and please remember that I am not a car enthusiast, so please be clear and overly precise in your explanation. Thanks again

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
47,513 POSTS

Yep, here is a guide that can help, and I found this information for your car:

Engineers design the Passlock TM system in order to prevent theft even if the various theft deterrent parts change. The Tamper mode will engage if any of the following components change:
- The Passlock TM lock cylinder
- The instrument cluster
- The powertrain control module (PCM)

If you replace any of the above components, 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, repeat the long tamper cycle from the beginning.

https://www.2carpros.com/articles/how-to-reset-a-security-system

To conduct an anti-theft system reset on a 1999 Chevrolet Cavalier, you can follow these general steps:

Check the Battery: Ensure that the vehicle's battery is fully charged. A weak battery can sometimes trigger the anti-theft system.

Turn Off Everything: Make sure all accessories, lights, and the ignition are turned off before starting the reset process.

Insert Key: Insert your key into the ignition and attempt to start the vehicle. If the anti-theft system is active, it may prevent the engine from starting or cut off the fuel supply.

Wait for 10 Minutes: Leave the key in the "On" position (do not turn it to start) for approximately 10 minutes. This waiting period allows the system to reset and reestablish communication between the key and the car's computer.

Turn Off the Ignition: After the 10-minute wait, turn the key to the "Off" position and remove it from the ignition.

Repeat the Process: Repeat steps 3 to 5 two more times for a total of three cycles. This ensures a thorough reset of the anti-theft system.

Start the Engine: After the third cycle, insert the key back into the ignition and start the engine. The anti-theft system should now be reset, allowing the vehicle to start normally.

Please go over these guides and get back to us.