Possible causes

– Low transmission fluid level
– Dirty transmission fluid
– Faulty shifting solenoid valve
– Shifting solenoid valve harness is open or shorted
– Shifting solenoid valve circuit poor electrical connection

When is the code detected?

Code P0788 is detected when the Engine Control Module (ECM) ECM detects open in solenoid valve ST circuit 4 times when solenoid valve ST is not operated

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0788 SCION Description

Shift solenoid valve ST is switched ON OFF by a signal from Engine Control Module (ECM) so that let in or out timing of 2nd brake is adjusted by operating orifice control valve. Therefore, shift solenoid valve ST operates when letting in or out reverse clutch.