OBD-II code · Powertrain (generic)
P01A4 Alternative Fuel Rail Pressure Sensor Performance
Alt fuel rail pressure sensor reading implausible.
Is it safe to drive with P01A4?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor reading drifted
- Less likelySensor element aged beyond calibration window
- Less likelySensor element contaminated by oil, soot or coolant
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Alt Fuel Rail Pressure Sensor
Related codes
- P01A1Alternative Fuel Tank A Pressure Sensor Circuit High
- P01A2Alternative Fuel Tank A Pressure Sensor Circuit Intermittent/Erratic
- P01A3Alternative Fuel Rail Pressure Sensor Circuit
- P01A5Alternative Fuel Rail Pressure Sensor Circuit Low
- P01A6Alternative Fuel Rail Pressure Sensor Circuit High
- P01A7Alternative Fuel Rail Pressure Sensor Circuit Intermittent/Erratic
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.