Circuit Description
WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The 1-2 shift solenoid (1-2 SS) valve controls transmission fluid pressure acting on the 1-2 shift valves to position the valves for the appropriate gear. The 1-2 SS valve is a normally-open exhaust valve located on the control valve body. A fused circuit supplies ignition voltage to the 1-2 SS valve. The TCM commands the solenoid ON or OFF by switching the ground path. When the 1-2 SS valve is commanded ON, the TCM senses low voltage. When the 1-2 SS valve is commanded OFF, the TCM senses high voltage. Refer to Shift Solenoid Valve State and Gear Ratio .
If the TCM detects a continuous open or short to ground in the 1-2 SS valve circuit, then DTC P0973 sets. DTC P0973 is a type B DTC.