P01C4 code meaning
Fuel Pressure Sensor A Circuit Range/Performance
Powertrain system Generic code P01xx codes Check engine light
What P01C4 means
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.
P01C4 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P01C4
- Check engine light on
- Hard starting or stalling possible
- Hesitation or lack of power under load
Common causes of P01C4
- Most likelySensor drifting or stuck
- PossibleGenuine supply fault: weak pump, clogged filter
- PossibleContact resistance at connector or ground
- Less likelyFuel pump control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel pressure sensor aFuel pump control moduleSensor wiringFuel pump
What each part of P01C4 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| C4 | The exact fault in that area. |
What to do next
- Note P01C4 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P01C4
What does P01C4 mean?
P01C4 means "Fuel Pressure Sensor A Circuit Range/Performance". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P01C4?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P01C4 fail an emissions test?
Yes, it can. P01C4 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P01C4 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P01C4 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.