P01C4Fuel Pressure Sensor A Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Fuel pressure sensor A is a fuel pressure sensor without 'rail' in its name and without a bank – unlike the rail pressure sensors P0190–P0194 and P01BE–P01C2; which sensor it is depends on the manufacturer. The only documented case is FCA, where sensor A is the low-pressure sensor in the supply line, read together with the fuel pump control module. GM calls its low-pressure sensor 'sensor B' (P018A–P018E). P01C4 is the plausibility fault: the signal is valid but stuck or does not match pump control – GM checks its equivalent low-pressure sensor by briefly changing pump output and expecting the pressure to move. No manufacturer document using exactly this code was found; the description rests on CARB's circuit monitoring requirement, the FCA sibling code P01C6 and GM's equivalent low-pressure sensor checks.
- What you may notice
- Check engine light on
- Hard starting or stalling possible
- Hesitation or lack of power under load
- Likely causes
- LikelySensor drifting or stuck
- PossibleGenuine supply fault: weak pump, clogged filter
- PossibleContact resistance at connector or ground
- RareFuel pump control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €50 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.