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.
The transmission control module (TCM) provides voltage to shift solenoid 1, 2, and 3 (SS1, SS2, and SS3) and pressure control solenoid 2 (PCS2) through a separate solid-state device called high side driver 2 (HSD2). HSD2 is continuously ON during normal operation, except during a brief circuit test. The TCM regulates control current to the solenoids by switching the appropriate low side driver ON and OFF.
DTC P2670 is a type A DTC.