P0785 GMC - 3-2 Shift Solenoid Circuit Electrical
- Dirty transmission fluid
- Faulty shifting solenoid valve
- Shifting solenoid valve harness is open or shorted
- Shifting solenoid valve circuit poor electrical connection
- Transmission may not shift to the next gear
The 3-2 Shift Solenoid (SS) valve assembly is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. The solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage through circuit 239. The Powertrain Control Module (PCM) controls the solenoid by providing a ground path. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The PCM varies the timing between the 3-4 clutch release and the 2-4 band apply depending on the vehicle speed and the throttle position.
When the PCM detects a continuous open, short to ground or short to power in the 3-2 SS valve assembly circuit, then DTC P0785 sets.