OBD-II code · Powertrain (generic)
P0842 Transmission Fluid Pressure Sensor/Switch A Circuit Low
The transmission fluid pressure sensor A circuit reports voltage below threshold, indicating short to ground or sensor failure.
Is it safe to drive with P0842?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal shorted to ground
- PossibleSensor failed
- Less likelyConnector pins corroded - high contact resistance
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Usually unaffected
- Parts involved
- Transmission Fluid Pressure Sensor, Wiring Harness
Related codes
- P083CTransmission Fluid Pressure Sensor/Switch G Circuit Low
- P0847Transmission Fluid Pressure Sensor/Switch B Circuit Low
- P084CTransmission Fluid Pressure Sensor/Switch H Circuit Low
- P0872Transmission Fluid Pressure Sensor/Switch C Circuit Low
- P0877Transmission Fluid Pressure Sensor/Switch D Circuit Low
- P0989Transmission Fluid Pressure Sensor/Switch E Circuit Low
- P0994Transmission Fluid Pressure Sensor/Switch F Circuit Low
- P083FClutch Pedal Switch A/B Correlation
- P0840Transmission Fluid Pressure Sensor/Switch A Circuit Range/Performance
- P0841Transmission Fluid Pressure Sensor/Switch A Circuit Range/Performance
- P0843Transmission Fluid Pressure Sensor/Switch A Circuit High
- P0844Transmission Fluid Pressure Sensor/Switch A Circuit Intermittent
- P0845Transmission Fluid Pressure Sensor/Switch B Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.