I think I know the answer, but...GM ECM # 16229684
Customer told me the ECM he was providing was from a 1999 Chevy Suburban, but after he dropped it off I see it looks like the OLDer style and has Service Number 16229684. These don't even use HS CAN at all, just single wire CLASS 2 Data using PIN 2 of the DLC/OBD. I still tried anyways, and my old GM Tech 2 will communicate with it on the bench, but HP Tuners/VCM will not. When I 'google' this part number, it ONLY shows it fits 1997 models and nothing newer at all. So I'm thinking they're confused and this never came out of a 99 model at all.
Am I right that these are a no-go?
THANKS:)
JEFF