Circuit Description
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition is turned on and the transmission control module (TCM) is powered up or when DTCs are cleared, the TCM performs a self-test to determine if the calibration is valid.
DTC P0602 is a type C DTC.