1998 Chevrolet Silverado 2500. Security light will not go off so I the truck wont stay running. I replaced the starter and now the truck starts but shuts down within a couple of seconds. The security light flashes then stays on. Tried to reset by doing the 10 minute intervals but with no success. Any ideas please help

 

1. Momentarily rotate the ignition key to the CRANK position (Do NOT start the vehicle), then release it to the RUN position (Do NOT key OFF in the process).
2. Wait 10 minutes. Observe the SECURITY indicator.
3. The SECURITY indicator will transition from flashing to ON briefly to OFF after 10 minutes if remaining in the ignition ON position.
4. Turn the ignition switch to the OFF position and wait for 10 seconds.
5. Repeat steps 3-6 two more times. The new security code is ready to be communicated among the Passlock sensor, EVO/Passlock module and VCM/PCM. The new password is learned on the next ignition lock cylinder cycle from OFF to CRANK to ON (start attempt).

 

did you find out what it was I’m having the same exact issue. Changed starter now it won’t run.

 

@pooh_lundy
that was three years ago, so this person may never be back. For best results, you should make a new post and include all your vehicle details and troubleshooting.