The shift/timing solenoids allow the automatic transmission to achieve seamless shifting according to driving needs. The Transmission Control Module (TCM) is responsible for monitoring and controlling the operation of these solenoids.
The purpose of the shift/timing solenoids is to help the transmission shift properly. The system is usually equipped with a variety of solenoids, which is why you should consult your vehicle’s information source to identify the “A” shift/timing solenoid in your vehicle.
When the DTC P0785 OBDII code is stored, it is because the Engine Control Module (ECM) found a general malfunction of the shift/time “A” solenoid circuit. This malfunction can be caused by electrical or mechanical problems.