You need to get it programmed. The theft deterrent is likely locking you out. I don't know why you changed it in the first place but you still may have another problem that the computer didn't fix also.

Answered by Wrenchtech (expert)
14,713 answers provided

Hi guys. Let me butt in and add a tidbit. If your van has the factory anti-theft system, use the key to turn the lock cylinder in the lift gate. That will program the Engine and / or Body Computer to work with the anti-theft system and allow the engine to run. If your van doesn't have the factory anti-theft system and you installed a used Engine Computer with that programming, it can't be "unprogrammed". You have to use a computer from another van that did not have anti-theft programming.

When it's in theft mode, the engine will typically run for just two seconds, then stall.

Answered by caradiodoc (expert)
17,256 answers provided