View Full Version : BCM wiring differences?
Bullit
07-31-2017, 05:28 PM
I did a 1996 A4 to 1995 M6 swap.I used the 95 M6 harness and everything went together fine the ignition coil was the only thing I changed.I seen that the BCM wiring had a few different wires on the 96 from the 95 harness but did not concern me until now.Has anybody did this type of swap using a little older harness and keeping the PCM current? My issue is the fuel pump is not priming and I know, I have to get in there and check for power but I wanted to hear some thoughts or any experience on this or a similar issue.
Bullit
07-31-2017, 06:53 PM
and and no spark as well....
Injuneer
07-31-2017, 09:47 PM
The 95 doesn't have a BCM. First year was 96.
Or possibly you meant to type PCM?
You show two cars in your signature. Did you take the engine, trans and wiring harness out of the 95, and install all in a 96 chassis using the 96 PCM? If so the body connector pinouts on the 96 don't all match up to the 95 harness. Shoebox's tables allow you to identify the mismatches.
http://shbox.com/1/harness_connector_faces.htm
Bullit
08-01-2017, 03:23 PM
Yeah and that is what I did and I have been going through the schematics to find what I missed.
Everthing on the PCM is almost the same but the c100 plug is a little different but should be fine.I just haven't found the issue and was hoping someone out there had a similar issue.
Thanks for the info on the BCM.
Injuneer
08-01-2017, 05:01 PM
Does the fuel pump run if you apply 12V to the prime connector near the PCM?
The fuel enable signal is a dark blue wire to pin A25 both 95 and 96. But the 95 gets the fuel enable from the TDM (theft deterrent module) and the 96 gets the signal from the BCM (body control module). Both those pass thru C230 on pin E. But even without the fuel enable signal, the pump should do the initial prime. And the prime connector bypasses the PCM enable and the fuel pump relay. 95 and 96 prime wire passes through C210 pin D, but 95 wire is gray, 96 wire is red.
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