Conditions for Setting the DTC: P0606
WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects that the TAC system has a process sequence error, clock error, and 2 motor processor errors, or ETC Internal Processor is not operating correctly. Each test runs in 12.5, 25, 50, 100 and 250 milliseconds. This DTC runs continuously.