OBD-II code · Powertrain (generic)
P084D Transmission Fluid Pressure Sensor/Switch H Circuit High
The transmission fluid pressure sensor/switch H reports a circuit high fault. Hydraulic pressure feedback for shift control is unreliable on this channel.
Is it safe to drive with P084D?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to B+
- PossibleOpen sensor
- 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
- Tfp Sensor H, Wiring Harness, Tcm
Related codes
- P083DTransmission Fluid Pressure Sensor/Switch G Circuit High
- P0843Transmission Fluid Pressure Sensor/Switch A Circuit High
- P0848Transmission Fluid Pressure Sensor/Switch B Circuit High
- P0873Transmission Fluid Pressure Sensor/Switch C Circuit High
- P0878Transmission Fluid Pressure Sensor/Switch D Circuit High
- P0990Transmission Fluid Pressure Sensor/Switch E Circuit High
- P0995Transmission Fluid Pressure Sensor/Switch F Circuit High
- P084ATransmission Fluid Pressure Sensor/Switch H Circuit
- P084BTransmission Fluid Pressure Sensor/Switch H Circuit Range/Performance
- P084CTransmission Fluid Pressure Sensor/Switch H Circuit Low
- P084ETransmission Fluid Pressure Sensor/Switch H Circuit Intermittent
- P084FPark/Neutral Switch Output Circuit
- P0850Park/Neutral Switch Input Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.