I have found out some things along the way, and will summarize them here in case it helps anyone:
Firstly, the OEM dash trim piece above the glove box
does not have an LED in the silver strip. Some folks have removed that strip from the trim piece (which is difficult) and retrofitted an aftermarket one from Aliexpress with an LED (with mixed results). I didn't want to do that, but still wanted the trims to match, so I ordered 5GM-858-418-A-YOI. It was initially backordered, and I assumed it would remain in that state forever, but it eventually shipped. It perfectly matches the trim in the GSW SEL door cards (Cyclone Black), so there's that.
Next, my 2019 GSW S
does not have highline door control modules. I thought it did because it has blind spot monitoring and heated mirrors, but was wrong. As
@mr-fix indicates in the description in
his video, highline door control module part numbers should end with 592 and 593. Mine end with 392 and 393. The lowline DCMs are not able to control the ambient lighting in the trim strip, or the door handle pocket light. Bummer.
And of course, my first thought was, 'It is because the facelift BCM does not support long coding, and I haven't found the adaptation that corresponds to setting Bit 01 in Byte 17.' Imagine how much time I lost trying to find that. And I am still wondering if there is an additional step needed...
I will probably try to source the appropriate DCMs, but as
@where2 indicates in
this post, you can't just install new DCMs, or DCMs salvaged from a random car, as there is some car model-specific 'ODIS parameterization' that is needed, even though the part number is correct. I presume if I were to source DCMs salvaged specifically from a 2019 GSW SEL, they would work. Beyond that, I have no idea the car models from which a salvaged DCM would work on a plug and play basis with my car, e.g., with no additional ODIS config needed.
@Cuzoe have you replaced your DCMs? How difficult was that process (removal and replacement)? Did you have remote coders address the ODIS configuration?
Finally, splicing into my OEM wiring harness to make a ground connection was a really sucky feeling. I know there are other ways, but I didn't want to wait another 3-4 weeks for more stuff to arrive from Aliexpress.