Car powers up but will not roll over

88THUNDER84

MEMBER
1999 CADILLAC SEVILLE
15,000 MILES

I replaced the ignition on a 99 sts and now the car powers up but will not roll over, the theft system comes on in the dash any suggestions. The car run fine until they lost the keys and I went and got a switch from the local salvage yard good switch and put it in making sure not to mess with any of the wires so its in and now nothing, the dash displays theft something dont remember, but the car will not roll over, did all the stuff they said to do like leave the car on for ten minutes and turn it on off 3 times after that but nothing. The dealer will not touch it cause it has a used ignition in it they wanted to put a new one in and well you know how that goes any suggestions

1 Reply

WRENCHTECH

MECHANIC
20,758 POSTS

You have to do a Passlock relearn after replacing the switch.

Disconnect the battery and hold the cables together for about 30 seconds then reconnect the cables before performing the procedure. Read it carefully if done incorrectly it won't work. If it helps let me know.
Turn ON the ignition, with the engine OFF.
Attempt to start the engine, then release the key to ON (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 through 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 CRANK).
Important
The vehicle learns the Passlock� Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. 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).