Working with RedMist on this issue, but wanted to document here for others.
After a VCDS scan, I had a code for the Secondary Air Pump and decided to replace both at the same time. After installing both pumps, I now have no communication to the ECU and the car won’t start. I have full electronics, except the engine won’t even attempt to turnover.
I have checked all fuses, and replaced all of the relays related to the ECU, but still no luck. During the repair, I did have to remove the ground connection in the passenger side wheel well, but I have since checked that to make sure it was secure, but there was no change.
Currently, I have a code for the ABS Valve Supply Voltage (01200). Not sure that this is related, but just about the only thing I can see in the scan as I have no OBD function with no ECU communication.
Current dash lights: Stabilization control fault, TPMS, Sport diff Fault, ABS and Brake light, Parking brake Malfunction (but oddly enough this is still working as expected).
Has anyone had similar issues? Any insight here would be greatly appreciated as I’ve hit a dead-end.