P0942Hydraulic Pressure Unit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- General fault of the unit that generates and stores hydraulic pressure for an automated gearbox or its auxiliary oil supply: motor-driven pump, accumulator and pressure control. Toyota sets P0942 on the 2001 to 2005 MR2 Spyder sequential gearbox together with the SMT warning light and a buzzing pump, or with gears that can no longer be changed; fluid seeping from the reservoir cap or the seal of the hydraulic power unit is a known cause, fixed with new seal rings. Ferrari reads P0942 on its DCT differently, as system pressure command signal too low. CARB requires functional checks of transmission outputs. P0943 and P0944 are the cycling and pressure-loss faults, P0945 to P0948 the pump control circuit.
- What you may notice
- Transmission or gearbox warning light on
- Pump buzzing or running for long periods
- Gears cannot be changed or shifts are delayed
- Auto stop-start disabled or engine restarts immediately
- Likely causes
- LikelyFluid loss at the reservoir cap or hydraulic power unit seals
- PossibleWorn pump motor or faulty pump relay
- PossibleDamaged wiring, connectors or power supply of the pump
- RareTransmission control module fault
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €150 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.