OK, I'm new here. I'm rebuilding a 2004 silverado 2500 out of 2 trucks. I had to do a cab swap because the truck was a rollover. Both trucks are 2004's. the truck I'm building is a 5 speed and the cab I'm using was an automatic. I used the dash harness that came on the cab because it has power door locks. I used the ecm, bcm, column, instrument cluster, and engine harness from the roll. The instrument cluster appears to be working correctly, other than the battery light stays on reguardless of the key position. The truck stalls after a second or 2 like the theftlock is kicking in, but the light is only flashes a couple times then goes out. It showed 1 code for throttle position that I cleared and never came back. I tried the relearn procedure with no luck. I could sure use some suggestions. thanks, Travis

Go back to the basics, find spark and fuel then go from there. You might need somebody with a tech 2 to unlock your security.

OK, I'm new here. I'm rebuilding a 2004 silverado 2500 out of 2 trucks. I had to do a cab swap because the truck was a rollover. Both trucks are 2004's. the truck I'm building is a 5 speed and the cab I'm using was an automatic. I used the dash harness that came on the cab because it has power door locks. I used the ecm, bcm, column, instrument cluster, and engine harness from the roll. The instrument cluster appears to be working correctly, other than the battery light stays on reguardless of the key position. The truck stalls after a second or 2 like the theftlock is kicking in, but the light is only flashes a couple times then goes out. It showed 1 code for throttle position that I cleared and never came back. I tried the relearn procedure with no luck. I could sure use some suggestions. thanks, Travis

if the engine starts then dies I say fuel pressure test....

Random ideas. We had a customer switych out steering columns on his chevy had to have Dealer re-program ignition key. Had a lexus do the start then die thing, MAF sensor. Had a Mitsubishi do the start and die, after market theft system. Just random thoughts. Hope one might help.

Random ideas. We had a customer switych out steering columns on his chevy had to have Dealer re-program ignition key. Had a lexus do the start then die thing, MAF sensor. Had a Mitsubishi do the start and die, after market theft system. Just random thoughts. Hope one might help.

bad MAF will throw dtc...if OEM security issue it will do nothing....no crank ,no fuel pump,computer stops all engine controls..

From all the other posts I read, it appeared that a security issue like swapping the bcm or lock cylinder will disable the fuel injectors and your vehicle will not run. But you will still be able to crank it and sound like it's going to run for a second or 2.

From all the other posts I read, it appeared that a security issue like swapping the bcm or lock cylinder will disable the fuel injectors and your vehicle will not run. But you will still be able to crank it and sound like it's going to run for a second or 2.

i second Twrecks. if it starts and dies right on, and security light flashes few times - BCM is disabling your fuel system. you can bypass it by rigging harness. i had post posted here on how to do this, but got chastized for that. maybe just click on my user name and go for "all posts". was about 2 mths ago.

ok, here it is:
http://www.automotiveforums.com/vbulletin/showthread.php?t=921090

are you using the key that is for the ecm,bcm? if the key your using is not in sync with the ecm or bcm then it ain't gonna run. try both keys . it should run with the correct key.

It's alive! I finally figured it out. There was 2 things wrong. For some reason it was in security but was not throwing the code causing the indicator light to come on. So I unpluged some stuff while cranking and forced it into security. Secondly the ignition cylinder was out of sequence with the harness and would not allow it to be turned fully to the off position, causing the battery light to stay on. after forcing it into security and fixing the ignition. I performed the relearn process and it fired up. Wow, what a mess. Thanks for all the help guys.

Here's the next question. I used the bcm from the truck with the power door locks, so they would work. But with that bcm my odometer dosen't show up. Do I need to have the cluster or bcm programed so that will work? thanks, Travis

Here's the next question. I used the bcm from the truck with the power door locks, so they would work. But with that bcm my odometer dosen't show up. Do I need to have the cluster or bcm programed so that will work? thanks, Travis

I believe that the vcm/bcm must be programmed to work with each other...the vcm and the odometer store mileage...separately...so I don't know how that can be resolved if the two units came from separate vehicles..


the schematics of the odometer circuits is not available but I believe that the illumination is sent from the bcm....connector c2 ppl /wht wire...pin a12...

The vcm and the cluster came from the same vehicle. just the body control came from another vehicle. everything on the cluster appears to work correctly even the message center, where the mileage is shown. other than it just dosen't show the mileage. It shows the mileage with the other bcm but the power door locks doen't work.