BCM UNIT 2009 FORD TRANSIT DIESEL DUAL CAB UTE

[Brigalow]

I have replaced the BCM 4 times in 6 months. Have checked all circuits found no faults. The last occassion was a brand new BCM from Ford Motor Company. The vehicle never got past the calibration stage before the CPU it fried . The technician said there was power backfeed from unidentifed source. Am at a loss as to what s the problem source. I am in Australia.

[knobby1]

I have replaced the BCM 4 times in 6 months. Have checked all circuits found no faults. The last occassion was a brand new BCM from Ford Motor Company. The vehicle never got past the calibration stage before the CPU it fried . The technician said there was power backfeed from unidentifed source. Am at a loss as to what s the problem source. I am in Australia.

If it is "frying" the BCM or PCM, there must be a short circuit in the system, full length of the wiring needs to be checked. BCM's and PCM's themselves rarely fail. If a short circuit is happening it should be blowing fuses. Obviously something strange going on.

Lord Knobrot

[Altransit]

Obviously something strange going on.

Could it be a spike from the alternator? If a diode or two from the rectifier pack has gone down, it could be supplying A/C current, or "dirty DC", which electronic circuits don't like much.


Just an idea

[knobby1]

Obviously something strange going on.

Could it be a spike from the alternator? If a diode or two from the rectifier pack has gone down, it could be supplying A/C current, or "dirty DC", which electronic circuits don't like much.
Just an idea

One would imagine it should still blow a fuse if over current or short circuit.

What sort of voltage do you have across the battery with engine running.

Lord Knobrot

[Radiofence]

I'd suggest checking earth's to alternator/ engibe. And for the cost of it, fit a genuine alternator.

[Airthies]

Check main engine earth and earth at seat base.
I had a van frying PCM and BCM which I think was the engine earth but ended up swapping out all dash and engine bay harnesses anyway.

Hope you get to the bottom of it.