BCM? Or??? HELP!
Thread Starter
Teching In
Joined: Apr 2009
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BCM? Or??? HELP! Hey guys, I need help here.
98 Camaro SS
I recently started putting my car Back together, had the dash out etc.. so after getting the harness back in the car I had to replace the power window module, everything back together, put power to it to make sure everything was working properly and it did. I put the dash back in.
Next day I go out to test the starter/ignition wire and make sure I have power with switch on and I hook power(battery) up and notice the BCM clicks, but no door chime, no power locks, no power windows. I took the BCM out, soldered the T joint, same issue. Checked all my grounds, checked all fuses everythings good. I do start getting a click from the BCM about every 10 seconds. I unplugged the green connector to the BCM to eliminate it being the window switches. I have checked to make sure the dash didn’t pinch any wires and made sure everything’s still plugged in.
next I unhooked the battery, and BCM for a few hours hook it all back up. BCM clicks once, but still nothings working. I have tested resistance to ground on every wire going to the BCM. Everything’s good. I have 12.9 volts at all the power wires (Red,brown,orange on black plug) and 0 blown fuses.
i tried using a jump box hooked straight to the stud
on the fuse block and grounded to chassis, nothing. But if I wiggle the power lead on the jump box a little I will get a cycle of the door locks locking and the door chime will go off once. I’m stumped and have no idea what’s going on. Any info or ideas would be greatly appreciated.
also car has no VATS. It’s on Holley efi.
98 Camaro SS
I recently started putting my car Back together, had the dash out etc.. so after getting the harness back in the car I had to replace the power window module, everything back together, put power to it to make sure everything was working properly and it did. I put the dash back in.
Next day I go out to test the starter/ignition wire and make sure I have power with switch on and I hook power(battery) up and notice the BCM clicks, but no door chime, no power locks, no power windows. I took the BCM out, soldered the T joint, same issue. Checked all my grounds, checked all fuses everythings good. I do start getting a click from the BCM about every 10 seconds. I unplugged the green connector to the BCM to eliminate it being the window switches. I have checked to make sure the dash didn’t pinch any wires and made sure everything’s still plugged in.
next I unhooked the battery, and BCM for a few hours hook it all back up. BCM clicks once, but still nothings working. I have tested resistance to ground on every wire going to the BCM. Everything’s good. I have 12.9 volts at all the power wires (Red,brown,orange on black plug) and 0 blown fuses.
i tried using a jump box hooked straight to the stud
on the fuse block and grounded to chassis, nothing. But if I wiggle the power lead on the jump box a little I will get a cycle of the door locks locking and the door chime will go off once. I’m stumped and have no idea what’s going on. Any info or ideas would be greatly appreciated.
also car has no VATS. It’s on Holley efi.
Last edited by nthaworx; May 13, 2020 at 04:15 PM.
Joined: Nov 2003
Posts: 11,328
Likes: 346
From: Jacksonville, FL (originally from Toronto Canada)
First, if you have a BCM, you have VATS. It can be bypassed with resistors and the fuel enable signal can be programmed to be ignored in a stock PCM (or not used in an aftermarket unit) but you can't program out the other parts of the VATS system in the BCM (e.g. starter relay control) because the BCM is not programmable.
I'm not clear on exactly what is not working other than the chimes, locks, and windows. Do any of the BCM functions work? Courtesy lights, hatch release, seat belt warning light, or radio (retained accessory power)? Does the starter engage? If none of those things are working then you apparently have a dead BCM. If so, replacement is the only option.
I'm not clear on exactly what is not working other than the chimes, locks, and windows. Do any of the BCM functions work? Courtesy lights, hatch release, seat belt warning light, or radio (retained accessory power)? Does the starter engage? If none of those things are working then you apparently have a dead BCM. If so, replacement is the only option.
Thread Starter
Teching In
Joined: Apr 2009
Posts: 10
Likes: 0
First, if you have a BCM, you have VATS. It can be bypassed with resistors and the fuel enable signal can be programmed to be ignored in a stock PCM (or not used in an aftermarket unit) but you can't program out the other parts of the VATS system in the BCM (e.g. starter relay control) because the BCM is not programmable.
I'm not clear on exactly what is not working other than the chimes, locks, and windows. Do any of the BCM functions work? Courtesy lights, hatch release, seat belt warning light, or radio (retained accessory power)? Does the starter engage? If none of those things are working then you apparently have a dead BCM. If so, replacement is the only option.
I'm not clear on exactly what is not working other than the chimes, locks, and windows. Do any of the BCM functions work? Courtesy lights, hatch release, seat belt warning light, or radio (retained accessory power)? Does the starter engage? If none of those things are working then you apparently have a dead BCM. If so, replacement is the only option.
Door chime, windows, and locks aren’t working, the hatch did work. I have no stock gauge cluster so none of the other stuff applies. I also don’t have any power at the starter ignition wire (purple) I’ve also tried 2 different bcm’s with the same result.
I can wiggle the positive battery lead and it will eventually make the door chime go off and the locks will cycle once, and also the rear hatch will pop.
Joined: Nov 2003
Posts: 11,328
Likes: 346
From: Jacksonville, FL (originally from Toronto Canada)
No power on the purple wire to the starter is probably VATS blocking the starter relay. Are either of the two BCMs the original one that matches your ignition key?
VATS would not block the locks so you may want to start there with some detailed testing. It sounds like you have experience with electrical wiring so I won't go into great detail on the mechanics of testing these things. You want to unplug the green 6-pin connector from the BCM and then provide independent power and ground to the gray and tan wires. Depending on which gets power and which gets ground, the driver's door will either lock or unlock. Reversing polarity would produce the opposite action. If the door lock responds then you know the lock actuators and the wiring from the BCM to the door is okay. You haven't said if you tried the door locks with the key fob or just with the door switches. If only with the switches then plug the green connector back into the BCM and use a back probe in the connector to ground the red/black wire. This should make the doors lock. If it does then you have a problem with the switches or the wires from them to the BCM, If it doesn't then the BCM is faulty.
VATS would not block the locks so you may want to start there with some detailed testing. It sounds like you have experience with electrical wiring so I won't go into great detail on the mechanics of testing these things. You want to unplug the green 6-pin connector from the BCM and then provide independent power and ground to the gray and tan wires. Depending on which gets power and which gets ground, the driver's door will either lock or unlock. Reversing polarity would produce the opposite action. If the door lock responds then you know the lock actuators and the wiring from the BCM to the door is okay. You haven't said if you tried the door locks with the key fob or just with the door switches. If only with the switches then plug the green connector back into the BCM and use a back probe in the connector to ground the red/black wire. This should make the doors lock. If it does then you have a problem with the switches or the wires from them to the BCM, If it doesn't then the BCM is faulty.
