Possible causes

– Low transmission fluid level
– Dirty transmission fluid
– Faulty Secondary Pressure Solenoid Valve
– Secondary Pressure Solenoid Valve harness is open or shorted
– Secondary Pressure Solenoid Valve circuit poor electrical connection

When is the code detected?

Engine Control Module (ECM) detectes an open or shorted condition on the solenoid circuit

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Transmission shift shock

P0778 MITSUBISHI Description

The secondary pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in response to a signal sent from the Transmission Control Module (TCM).