[Robby]

The new part has to be 'introduced' to the BCM in so many words.

The replacement part currently can't be identified because the BCM does not recognize the parts new broadcast code.
A 'Lost Communication' code results.....the BCM does not recognize the new code coming through the system.....it is looking for the previous code that was assigned to the old part.

For whatever it is worth, the level of complexity is more aggravating by the day.......all in the name of reducing the amount of secondary switches and wiring.....ugh.

Rob

 

[NickD]

I find this difficult to believe also, just a form C switch that grounds the BCM one way or the other depending on whether the door is locked or unlocked. Switch can be tested with an ohmmeter, and anything that feeds the BCM has practically zero current, no power arching like in a real power switch. So must be a very clean switch, just the slightest bid of corrosion on it will prevent its operation.

Ha, never was a problem back then, zero wires went to the doors, today have a ton of them, windows, locks, mirrors, child safety, speakers... Also use to use the minimum of 16AWG wire, not because of the current flow, because it was far more robust. But now finding 28 AWG wire, cheap, and the current flow is next to zero.

Major problem is in sub zero weather, would very carefully open the doors and close them and just wide enough to get in or out, with that cheap plastic insulation in cold weather, those wires can snap into two, and its a very long ride from those doors to the BCM. On some vehicles, had to replace all that crap with 16 AWG neoprene wire that is not subject to cold weather, talk about an all day job.

Did anyone check the continuity of those wires clear to the BCM? Could well be your problem. Another problem is using insulation displacement terminals, sure made the bean counters happy, didn't have to strip the ends of the wires anymore, but just a tiny point contact from a brass terminal to bare copper.

Ha, use to have to hand crank down the window to adjust the side view mirrors, and push a button to lock the doors, but now we have convenience or do we? Aribags kicked out the speakers to the doors. Only good to 25 mph if you are not wearing your safety belt, but good for under 40 mph if you are.

 

[NickD]

Wires terminate on pins 15 and 19 on BCM plug X2 for the drivers sides lock/unlock switch.