30-Minute Learn Procedure
Important: Do not remove the key from the ignition during this procedure. If the key is removed, the procedure will have to be performed from the beginning.
Turn ON the ignition, with the engine OFF.
Attempt to start the engine, then release the key to ON. The vehicle will not start.
Observe the SECURITY telltale. After approximately 10 minutes, the telltale will turn OFF.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1-4 two more times for a total of 3 cycles/30 minutes. The vehicle is now ready to relearn the Passlock Sensor Data Code and/or passwords on the next ignition switch transition from OFF to RUN.
Important: The vehicle learns the Passlock Sensor Data Code and/or password on the next ignition switch transition from OFF to RUN. You must turn the ignition OFF before attempting to start the vehicle.
Start the engine. The vehicle has now learned the Passlock Sensor Data Code and/or password.
With a scan tool, clear any DTCs if needed. History DTCs will self clear after 100 ignition cycles.
My 2005 Trailblazer has starting problems ... it starts whenever it wants. I've had fuel pump replaced and ignition switch. Now six months later, several mechanics and garages ...still doing it. Nobody seems to be able to figure it out. Any thoughts? Thanks.