Chosen Solution
When I start my truck it starts and immediately stops. What would cause this?
I had the same problem , I changed the fuel pump and it has not turned off since
Passlock/passkey sensor needs to be replaced. This is the cylinder housing your key switch goes into.
Check antitheft passlock module-located behind ashtray compartment. My circuit board was burnt in 3 places
It is the pass lock security system
You may have inadvertently turned the key on and left it on for just the right amount of time then turned it off where-by starting the key learn sequence in GM’s Vehicle Anti Theft System or VATS . The VATS may not be programed to the key now and all you have to do is go to this link and follow the directions. My ignition on my 1999 Tahoe was vandalized, and the Anti-theft is Good luck and I hope it works.
