BCM vs VCM?

[Sugar Ray]

2003 Silverado ran for 10 minutes then died. After several minutes restarted and ran fine. Next morning backed up the driveway then died. Opened hood, started, then as soon as hood was closed it died. Currently showing anti-theft light. Plan on replacing ignition cylinder, ignition housing and ignition starter switch. But I suspect more... Could I also need BCM? But that wouldn't cause it to die after it had started. Could it be VCM/PCM?

 

I've tried the 3 steps to reset anti-theft by turning key on and wait 10 minutes x 3 but the engine won't start at all now. The dash also shows --- mpg and ---range rather than being able to show an actual number. Also, the daytime running lights stay on and won't turn off; that might seem to be from BCM. Last, I hear a high pitched electric sound in the engine compartment. Could somehow both BCM and VCM gone out at the same time or is it something else?

Thanks...

[Sugar Ray]

I should clarify that I intended to perform the 3 steps to reset, but wasn't able to because the anti-theft light never goes off no matter how long I wait.

[Doug_Scott]

You need to stop thinking so much. Do one thing at a time, and proceed in a logical fashion instead of doing a number of incomplete procedures. The very first thing to do is remove both battery cables (negative first to remove any chance of having wrench slip and shorting positive cable to chassis or body). Clean both cable ends and posts of battery. Do not just assume they are clean because they look clean, actually clean them. Also take the ground cable off the at the other end, and inspect the cable end while bending and twisting the lug connector at the end, look for any powdery crap under the insulation where the lug connector and wire meet. If there is any stuff there, replace the entire cable. Connect cables back up again, doing the ground cable at the battery last in the order. Make sure connections are tight. Check each and every fuse in both fuse panels. Take the engine compartment fuse panel out and look at the underside. You are looking for any obvious corrosion on the connections.

 

Now start the security light procedure. Do each step completely, and use a time keeping device if you will not be able to count to 600 in 10 minutes without interruptions like the wife coming in offering sex, and making you lose where you were in the count.

 

Found this procedure online:

Need the use of a scanner as an OBDII will only get P codes you are looking for B codes
Ignition switch is more common to fail and need codes to conform suspicion
Try and do 30 Minute Learn Procedure
Turn ON the ignition, with the engine OFF.
Attempt to start the engine, and then release the key to ON, vehicle will not start.
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
Turn OFF ignition, and wait 5 seconds.
Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes, the vehicle is now ready to relearn the Passlock Sensor Data Code and/or Passwords on the next ignition switch transition from OFF to CRANK.
IMPORTANT: The vehicle learn the Passlock Sensor Data Code and/or Password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

Start the engine. The vehicle has now learned the Passlock Sensor Data Code and/or password.
With a scan tool, clear any DTCs if needed. History DTCs will self clear after 100 ignition cycles.

[Sugar Ray]

A couple of days ago I had to remove the battery cables because that was the only way I could get the daytime running lights to turn off. The cables are good. Are those daytime lights controlled by the BCM? Or are they controlled by something else?