Silverado Passlock Security Problem

I think that after you do that, it should just start the next time you try. If it doesn't, most likely there's something else wrong. In that case, you'd likely need a Tech 2 scan tool to diagnose it.

What parts did you replace exactly? The BCM and/or PCM?

The theft deterrent system has been incorporated into the body control module (BCM). The theft deterrent is provided in order to prevent the vehicle operation if the correct key is not used in order to start the vehicle. The ignition key turns the lock cylinder. The cylinder rotation produces an analog voltage code in the PasslockT sensor. This voltage code is received by the BCM. The BCM compares the voltage code to the previously learned voltage code. If the codes match, a class 2 message is sent from the BCM to the powertrain control module (PCM)/vehicle control module (VCM). The message enables the fuel injectors

That's a little snipper straight from the manual.. I do not know of any way to bypass it... you need to have the BCM awake and functioning... maybe you haven't finished putting the rest of the dash back together??? The system includes the PCM,BCM, and the passlock housing which is part of the ignition cylinder... If you want I can send you almost anything you want, but the diagnostics are useless without a scan tool, and I think it has to be a TECH II , dealer equipment... You can do some voltage checks.... oh ya the BCM is the plastic module directly under the column...

Thanks for the responses.

The BCM has been replaced, and the vehicle was taken to a mechanic who did a scan that supposedly reset the BCM. I've taken the vehicle to other mechanics who have been unable to start it successfully as well.

Since the security system is controlling the fuel injectors, would it be possible to bypass the security system (assuming I can get the wiring schematic) and apply power directly to the fuel injectors? Having a functional vehicle is more important than having this security system. Hopefully I can find the schematic and this is possible.

Thanks again.

There is no way to bypass it that I know of... The BCM doesn't take away power or anything, It has to see a valid passlock code before it will send an encoded password to the PCM via the class 2 data line.... I know of no way to mimic the password.. You may try some kind of stolen car web site or something???? lol If you have a mechanic who can reset????? the bcm then he should have been able to diagnose where the problem was.I can send you the schematics, but you have to start with the simple stuff... do a data check... does the bcm send a state of health message along the class 2??? does it read a valid passlock voltage?? It's actually simple with a Tech 2.Does your mechanic have access to one??? I will try and send you the schematic and/or pinouts of the bcm.. I would check all the powers and ground... Hopefully it's a simple problem...Bobo

replying to Bobo, bhalsdorf wrote: As far as I know there is no way to reset a BCM. It would have to be replaced and flashed by a dealer in order to work properly. And then the relearn for the ignition key needs to be done.