I own a 1998 Chevrolet C1500 Extended Cab PU. I have been having a issue for a couple of years now with it not starting on and off now. Security light flashes each time and I have to do the 15-20 minute waiting game while key turned on until light stops flashing and then starts up afterwards. No codes or check engine light ever comes on. Just security light flashing problem. Truck runs great when I can drive it. Been trying to to some research on why and how this is happening. It doesn’t do it all the time just on and off. The built in anti theft system that they put in these trucks is malfunctioning. I do not have a key with a chip or whatever you call it inside, just a regular key. Even took out module and put it back in and didn’t have issue for a year. Now it’s doing it more frequently again. What can I do to fix this issue permanently? Please help thank you!
Try your other key. Don't recall the years, but some of those charged a battery in the key when in ignition but with bad bat... can lead to that issue because initially the signal from key isn't good because the bat in it isn't of sufficient voltage yet but after a bit of time the charge circuit can bring it up enough to operate. But when removed, charge depletes rapidly because of bad bat. Gets worse over time...
Key pic?
Also bypasses aren't that hard as it usually just kills injector power and ign fire via a signal to ecm. Rewiring to a hot while on wire can take care of a bypass.
try to find some computer nerd who knows how to do that I've never personally done it but on the internet there are lots of guys that have various kits and ways of disabling the entire system
Sometimes if you have power locks it is recognized by the computer and will disable the immobilizer if you get out of the car and lock and unlock the door with the key. Now it doesn't always work but usually if it starts doing this its about a 50 50 shot.
