P0846 Volvo 2-4 or 2C Pressure Switch Rationality

Possible causes

– Faulty Pressure Switch Rationality
– Pressure Switch Rationality harness is open or shorted
– Pressure Switch Rationality circuit poor electrical connection
– Internal transmission damage
– Faulty Engine Control Module (ECM)
– Faulty Transmission Control Module (TCM)

Symptoms

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

P0846 Volvo Description

The Transmission Control Module (TCM) has detected a fault in the pressure switch assembly