Possible causes

– Low transmission fluid level
– Dirty transmission fluid
– Faulty High & Low Reverse Clutch Solenoid valve
– High & Low Reverse Clutch Solenoid valve harness or connectors
– High & Low Reverse Clutch Solenoid valve circuit is open or shorted

When is the code detected?

The P0766 code is detected when the ECM has detected a mechanical fault with the solenoid energized, valve stuck off

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Transmission will not shift gears

P0766 KIA Description

High & Low Reverse Clutch 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.