Possible causes

– Low transmission fluid level
– Dirty transmission fluid
– Faulty line pressure solenoid valve
– Line pressure solenoid valve harness is open or shorted
– Line pressure solenoid valve circuit poor electrical connection

When is the code detected?

The gear required by the Engine Control Module (ECM) does not match the actual gear when driving

Symptoms

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

P0746 GMC Description

The line 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).

GMC Technical Service Bulletins for P0746 code