Swapping OBC's as diagnostic - safe?

[kiev]

Wrong VIN is a show stopper.

If it were my car i would put everything back into the car it came out of, then pull DTCs and do troubleshooting with those.

This thread started with an off-hand question but has developed into a case of full blown car aids and the throwing of parts.

Swapping parts without knowing why is not troubleshooting and not diagnostics either. That should have been the answer to the OP.

 

[MickeyS70]

Wrong VIN is a show stopper.

Agreed, but I’m curious how far one can get before the show eventually stops

If it were my car i would put everything back into the car it came out of, then pull DTCs and do troubleshooting with those.

But what do you do if there aren’t any relevant DTCs?

Swapping parts without knowing why is not troubleshooting and not diagnostics either. That should have been the answer to the OP.

Like you, I’m old school and like to pinpoint a fault before replacing a part, however in the absence of a ‘smoking gun’ ruling out components by changing them is another strategy that is quite commonplace these days.

Also just unplugging and putting connections back can be surprisingly productive..

 

[pbui19]

The VIN block is so ridiculous and malicious. There are clever people out there who can program in the new VIN. Once I had to ship an ebay HMI (Human Machine Interface) unit from a Chevy Volt to an outfit in to Canada, may be Vancouver (can't recall exactly right now), to reprogram the VIN. Obviously it's only possible with the proper set up and VIN is stored on a flashable chip.

 

[MickeyS70]

The VIN block is so ridiculous and malicious. There are clever people out there who can program in the new VIN. Once I had to ship an ebay HMI (Human Machine Interface) unit from a Chevy Volt to an outfit in to Canada, may be Vancouver (can't recall exactly right now), to reprogram the VIN. Obviously it's only possible with the proper set up and VIN is stored on a flashable chip.

Dealers do this work regularly, it should be a quick job with a MUT3 or Diagbox diagnostics tool

 

[jpr]

Wrong VIN is a show stopper.

If it were my car i would put everything back into the car it came out of, then pull DTCs and do troubleshooting with those.

This thread started with an off-hand question but has developed into a case of full blown car aids and the throwing of parts.

Swapping parts without knowing why is not troubleshooting and not diagnostics either. That should have been the answer to the OP.

I initially wanted to swap OBC's because the initial diag (no relevant DTC's) led me to believe the OBC was faulty. That's doing it for a reason, IMO. I should probably have just swapped them, because in fact the OBC was fine.

I did list the DTC's in post #28 but again it seems like there are none relevant.

 

[jpr]

Oddly, the good car does charge fine with the bad car's EV-ECU, or battery control unit, or body control unit, installed. Didn't expect that, for a couple reasons.

 

[MickeyS70]

Oddly, the good car does charge fine with the bad car's EV-ECU, or battery control unit, or body control unit, installed. Didn't expect that, for a couple reasons.

Agreed, but at least we know now what isn’t causing the issue, no active components left as far as I can see therefore back to the wiring loom?

Might be worth swapping all the ECUs back and closely examine the corresponding connectors on the ‘bad car side’ while you’re at it.

What’s also intriguing is the B1108 fault that shouldn’t be there with the heater turned off? What dongle/app do you use to read DTCs? Do you see any fault codes on the ‘good’ car?