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Another update in this slow epic. As of my last posts, I was trying to get the car running so I could move it to my new house. Unfortunately, despite some direct assistance from Bill Curlee, I didn't manage to get it running in time and ended up having it flat-bedded to my new place.
My final attempt to get the car started involved directly linking the body control computer to the PCM, bypassing the common trouble makers such as the door control modules and the seat control module. I did my best to follow Bill's instructions (both verbal and from another post) so I *think* I did it right. Since this didn't work, it leads me to suspect the body control module may be malfunctioning.
I have now removed the BCM from the passenger footwell and opened it up for examination. It is bone dry (and was at the time of my last post) but I believe it has been exposed to water before. What I'm not sure of is whether there's residual damage or any sort of build-up that might be causing it to malfunction.
Below is a picture of the most suspicious looking parts of the board. If you look closely you can see white streaking in some areas. One connector seems to have some sort of white-ish build up. Is this the sort of stuff that could cause a malfunction?
My plan at this point is to get some electronics cleaner and a soft brush and attempt to clean this up. Then I'll stick it back in the car, clear the codes and see what happens. Anyone have any other suggestions?
Thanks!!
Scott
BCM from 2002 Z06
See if you can remove that corrosion with some alcohol and a nylon brush (toothbrush) and see if that makes any difference.
Are you positive that ALL the BCM & PCM fuses are good and have the proper power being supplied to them????? Please measure those fuses with a volt meter.
Hi everyone,
time for another update. I ordered some Electronics cleaner and nylon brushes from Amazon. Last weekend I carefully scrubbed down the parts of the board that appeared to have corrosion, and I believe I got all of it off. I have a couple of pictures which I can post if anyone is interested in the before and after. I also gave the whole board a gentle wash with the electronics cleaner. I reinstalled the board in the housing for the body control module, and reinstalled that in the car. I also reconnected the star connectors so the full bus is hooked together as it should be. I turned the car on and it exhibited the same symptoms as before. After clearing all the codes I found that I currently have the same core set of codes showing up that I had before. No communication with the body control module, no communication with me HVAC or IPC, and a couple of codes from other modules indicating that they had lost communication with body control module. No codes for the door models now. At this point I really suspect that the BCM is bad. Oh, I also intend to double-check all of the fuses. But I did check all of those with a volt meter back in September, and they were all good.
Does anyone have any other suggestions for things that I should be checking, or ways that I can validate the hypothesis that the body control module is the problem. Assuming that the BCM is bad, what's the best way to go about getting one that is a match for my car? Also it sounds like installing a new BCM sometimes requires reprogramming but not always. Does anyone know what determines this? Finally, if I do have to replace the body control module are there any opportunities to make this an upgrade? For example are there any features or accessories that are controlled by the body control module which would require me to choose a slightly different version if I wanted to add them to the car?
Before you get too far into module replacement, please get a DC Volt meter and measure all the fuses at the fuse test points on top of each BCM/PCM fuse to ground. Make sure that you actually have proper (FULL BATTERY VOLTAGE) power to each fuse.
If there isn't proper power to each module, it will not work and report as NO COMMS.
REMEMBER! Some fuses are HOT AT ALL TIMES and some are only hot when the ignition switch is in the RUN/ON position
