P0755 Kia - Underdrive Solenoid Valve System
- Dirty transmission fluid
- Faulty underdrive solenoid valve
- Underdrive solenoid valve harness is open or shorted
- Underdrive solenoid valve circuit poor electrical connection
- Transmission will not shift gears.
Underdrive solenoid valve is turned ON or OFF by the Transmission Control Module (TCM) in response to signals sent from the park/neutral position (PNP) switch, vehicle speed and Engine Control Module (ECM) (throttle opening). Gears will then be shifted to the optimum position.