BCM Replacement
03-29-2021, 10:07 PM
#1
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BCM Replacement Looking to replace my BCM but having a hard time finding one. My is a Integrated Body Control Module DE: 09353691 and Ive already reflowed solder on the trouble relay. Thanks for any help!
03-30-2021, 09:34 AM
#2
Let's start with what makes you consider that a BCM replacement is necessary? BCMs can fail but other than the RAP circuit fix (the solder joint), they are often blamed for things when the fault turns out to be something else. BCMs are pretty sturdy (again, other than the solder problem) and very seldom fail. That's why they've been long discontinued - there simply wasn't enough demand to keep producing them.
If you describe the symptoms you're experiencing, perhaps we can give you alternatives and save you some money.
If you describe the symptoms you're experiencing, perhaps we can give you alternatives and save you some money.
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fucter (03-30-2021)
03-30-2021, 10:40 AM
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Problems Let's start with what makes you consider that a BCM replacement is necessary? BCMs can fail but other than the RAP circuit fix (the solder joint), they are often blamed for things when the fault turns out to be something else. BCMs are pretty sturdy (again, other than the solder problem) and very seldom fail. That's why they've been long discontinued - there simply wasn't enough demand to keep producing them.
If you describe the symptoms you're experiencing, perhaps we can give you alternatives and save you some money.
If you describe the symptoms you're experiencing, perhaps we can give you alternatives and save you some money.
03-30-2021, 02:15 PM
#4
Well, the fact that the window motors aren't related to the BCM except for using the Retained Accessory Power (RAP) circuit, which is what the solder fix is for, it certainly appears that the BCM might not be the issue. Does your radio work? If so, you can eliminate the RAP circuit since the radio and windows share that.
Have you checked the obvious - a blown fuse? In this case, the COURTESY fuse is the one which powers the door locks. Always check a fuse with a multimeter or fuse tester, not just by a visual inspection. A fuse (especially a 20+ year old one) can look fine but still be blown. Actually, for the few cents they cost, it's usually better to just replace a suspect old fuse.
If that doesn't solve the problem, I can walk you through electrical tests to diagnose it if you have a test light or multimeter and want to spend some time on it.
As far as the indicator light... which one isn't working? The BCM controls only the seat belt and security lights so any other indicator lights are unrelated.
Have you checked the obvious - a blown fuse? In this case, the COURTESY fuse is the one which powers the door locks. Always check a fuse with a multimeter or fuse tester, not just by a visual inspection. A fuse (especially a 20+ year old one) can look fine but still be blown. Actually, for the few cents they cost, it's usually better to just replace a suspect old fuse.
If that doesn't solve the problem, I can walk you through electrical tests to diagnose it if you have a test light or multimeter and want to spend some time on it.
As far as the indicator light... which one isn't working? The BCM controls only the seat belt and security lights so any other indicator lights are unrelated.
03-31-2021, 01:45 PM
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Sorry for the late return. I did meter the courtesy fuse it was good but went ahead and replaced it. When I hit the unlock switch on the drivers door, I can hear the relay clicking in the BCM but no movement on the door lock actuator. Thanks for the help!
04-01-2021, 09:19 AM
#6
The lock relays clicking is a good sign.
Do you have electrical diagnostic equipment (multimeter and/or test light, or even a device like a PowerProbe) and how far do you want to go with diagnostics?
Here's something you can try even without equipment... The power door locks are entirely dependent on the BCM whether using the switches in the doors or the remote key fob. We can assume that the wiring from the switches to the BCM is okay since you hear the relays click. So the thing we want to test next is the connection from the BCM to the lock actuators. Of the three connectors in the BCM, the green 6-pin is the one with all the door lock wires. Unplug it from the BCM. You'll need a couple of pieces of wire long enough to reach a power source and a ground (a test light is excellent for the power side because the light bulb prevents accidentally creating a short circuit). There is a stud behind the right kick panel which makes a good ground... you'll find a couple of ground wires already connected there. Once you have your power and ground wires, you can insert the other end of the wires into the pin openings in the green connector to see what response you get. It's okay to insert the ground side and leave it there but it's best to just touch the power side momentarily to avoid burning out the actuator.
Gray to power, tan to ground... lock driver's door
Gray to power, gray/black to ground... lock passenger's door
Tan to power, gray to ground... unlock driver's door
Gray/black to power, gray to ground... unlock passenger's door
Assuming you don't get those results, then it would be time to remove a door panel and test the actuators directly to determine if it's a wiring problem or an actuator problem.
If you do get the correct results then you will want to test the signal from the switches. These are grounding switches so you would use your meter or test light to check that you get ground on the red/black wire when pressing either door switch to lock, and ground on the orange/black wire when pressing either switch to unlock.
Do you have electrical diagnostic equipment (multimeter and/or test light, or even a device like a PowerProbe) and how far do you want to go with diagnostics?
Here's something you can try even without equipment... The power door locks are entirely dependent on the BCM whether using the switches in the doors or the remote key fob. We can assume that the wiring from the switches to the BCM is okay since you hear the relays click. So the thing we want to test next is the connection from the BCM to the lock actuators. Of the three connectors in the BCM, the green 6-pin is the one with all the door lock wires. Unplug it from the BCM. You'll need a couple of pieces of wire long enough to reach a power source and a ground (a test light is excellent for the power side because the light bulb prevents accidentally creating a short circuit). There is a stud behind the right kick panel which makes a good ground... you'll find a couple of ground wires already connected there. Once you have your power and ground wires, you can insert the other end of the wires into the pin openings in the green connector to see what response you get. It's okay to insert the ground side and leave it there but it's best to just touch the power side momentarily to avoid burning out the actuator.
Gray to power, tan to ground... lock driver's door
Gray to power, gray/black to ground... lock passenger's door
Tan to power, gray to ground... unlock driver's door
Gray/black to power, gray to ground... unlock passenger's door
Assuming you don't get those results, then it would be time to remove a door panel and test the actuators directly to determine if it's a wiring problem or an actuator problem.
If you do get the correct results then you will want to test the signal from the switches. These are grounding switches so you would use your meter or test light to check that you get ground on the red/black wire when pressing either door switch to lock, and ground on the orange/black wire when pressing either switch to unlock.
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04-07-2021, 06:16 PM
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I have 11.4 VDC at each door panel switch. orange w black stripe and red with black strip is power black is ground. I get 11.5 vdc at the actuator connector gray and gray with black stripe. my grounds seem little high. The actuators act like they want to work but don't have enough power. Thanks for any help!
04-08-2021, 08:32 AM
#9
Unfortunately, that isn't the testing I suggested and those results are essentially meaningless. 11.4 volts is a common battery level voltage when the engine isn't running so there is nothing unusual there.
The orange/black and red/black wires are simple grounding signals for unlock and lock respectively. The gray, gray/black, and tan wires are the reversing power/ground for the actuators. They should have nothing when the switches are at rest (although the BCM may leave them at ground potential at rest).
As long as you're in the door anyway, try applying independent power to one side and ground to the other to check if the actuators work. Gray to power and tan to ground will lock the driver's door. Gray to power and gray/black to ground will lock the passenger's door. Tan to power and gray or gray/black to ground will unlock the corresponding door. Doing that will eliminate the BCM, switches and wiring from the test and let you know if the actuators work. Then you can start back with the tests already described.
The orange/black and red/black wires are simple grounding signals for unlock and lock respectively. The gray, gray/black, and tan wires are the reversing power/ground for the actuators. They should have nothing when the switches are at rest (although the BCM may leave them at ground potential at rest).
As long as you're in the door anyway, try applying independent power to one side and ground to the other to check if the actuators work. Gray to power and tan to ground will lock the driver's door. Gray to power and gray/black to ground will lock the passenger's door. Tan to power and gray or gray/black to ground will unlock the corresponding door. Doing that will eliminate the BCM, switches and wiring from the test and let you know if the actuators work. Then you can start back with the tests already described.