[Cujo98]

99 Silverado 5.3l 1500 is displaying the passlock security issues. Starts, runs for a second or two then stall out. Security is displayed in the message center 24/7 truck on or off. With key in on position it does the usual flash between it and battery. Also key fob has stopped responding (also tried with new battery), no dome lights/tail lights or gauge backlighting. No present dtc’s. Also have checked all fuses(good).

Truck has had zero past issues and was running fine when it was last driven about a week ago.

have tried the passlock key 10x3 relearn, left the key in the on position after it stalled out for over and hour and tried to no avail, unhooked battery and let sit for a couple hours. No matter how long I leave it the security light will no go off. Probably renders the 10x3 relearn useless

would love some insight into this as it’s got me puzzled

 

[Vegas Avy Guy]

Could be a bad body control module. Mine did that a while back too. Went into anti-theft mode and would only start for a second. I cant remember exactly what I did but here's what I found on the web from GM for resetting it:

Exit the vehicle and unlock the car using the key fob. Insert the key into the outside door handle and turn it right and then left to lock and unlock. This can be done to either the driver's or passenger door. Insert the ignition key and crank the engine over. Hold the panic button down to disable the alarm. Push unlock button and try starting it. If that doesn't work disconnect the car battery by removing the negative cable end.

Though I think I just unplugged the BCM and plugged it back in.

 

[Cujo98]

Reading up I feel like it may be the bcm that has gone out on me. My drl’s went out a while ago despite good fuses and relays and now with all interior lights, tail lights out and it not responding at all to the key fob (means I can’t use your solution above but appreciate it) makes me think the bcm **** the bed. Or I have a broken power wire to the bcm but I’m having a hard time finding a wiring diagram for it.

 

[brian c lindsey]

could be passlock control module went out, if so you will have to replace it, i think rock auto has them , if not they are avail on ebay

 

[Cujo98]

I’m starting to think it’s the bcm given all the associated outages but I can’t find a single way of testing it online. Also can’t get the security light to turn off at all. It’s on 24/7 key on or off

 

[redvett]

Use a scanner and interrogate the BCM also clear all codes current and history for a starter, if you cannot talk to the BCM ist most likely fried. Have you been jumping vehicles with a pair of jumper cables? This procedure is not recommended any more due to reverse polarity chances or current spikes.

 

[Cujo98]

Problem solved

Found corroded wires on the plug harness that connects to the underside of the fuse block in the engine bay. Changed the wiring harness (burnt/corroded) plug and fixed the broken ends and now the truck is back to normal operation.

 

[Vegas Avy Guy]

Good to hear.

I'll remember to check that too if I ever have this issue again.

 

[Topkicktrucker]

Reading up I feel like it may be the bcm that has gone out on me. My drl’s went out a while ago despite good fuses and relays and now with all interior lights, tail lights out and it not responding at all to the key fob (means I can’t use your solution above but appreciate it) makes me think the bcm **** the bed. Or I have a broken power wire to the bcm but I’m having a hard time finding a wiring diagram for it.

I have that trouble with a 99 5.7 Tahoe runs for a second and shutdown been a long road to fix still down since last October sitting in snow now Minnesota weather