P0756 GMC 2-3 Shift Solenoid Valve Performance – No First or Second Gear

Possible causes

– Low transmission fluid level
– Dirty transmission fluid
– Faulty 2-3 Shift Solenoid Valve
– 2-3 Shift Solenoid Valve harness or connectors
– 2-3 Shift Solenoid Valve circuit is open or shorted

When is the obd code mean?

When the Powertrain Control Module (PCM) detects a 4-3-3-4 shift pattern, then DTC P0756 sets.

Symptoms

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

P0756 GMC OBD Code Description