P018C code meaning
Fuel Pressure Sensor B Circuit Low
Powertrain system Generic code P01xx codes Check engine light
What P018C means
Fuel pressure sensor B is a second fuel pressure sensor; which one is up to the manufacturer. On GM it is the low-pressure sensor in the supply line of direct-injection engines (0–743 kPa), read by the engine module or the fuel pump control module; on Ford engines with dual injection it is the sensor on the port-injection rail (0.5–4.5 V for about 0–70 psi). Sensor A is the high-pressure rail sensor (P0190–P0194). P018C means the signal voltage is below its lower limit – a signal wire shorted to ground, or an open signal or 5 V reference wire; a short on another sensor sharing the reference can also pull it down. GM sets it below 4 % of the reference (about 0.2 V), or below 0.14 V when the sensor is read by the fuel pump module, in 64 or 72 of 80 samples; two trips. Ford sets it below 0.049 V for 8 s. The control module then uses a fixed value or fixed pump control.
P018C at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P018C
- Check engine light on
- Starting problems
- Lack of power or stumbling
- Sometimes no symptoms
Common causes of P018C
- Most likelySignal wire shorted to ground or open
- Possible5 V reference missing or shorted (also by another sensor on the circuit)
- PossibleSensor faulty
- PossibleConnector corroded
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel pressure sensor bSensor wiringSensor reference voltage
What each part of P018C 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. |
| 8C | The exact fault in that area. |
What to do next
- Note P018C 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 P018C
What does P018C mean?
P018C means "Fuel Pressure Sensor B Circuit Low". Fuel pressure sensor B is a second fuel pressure sensor; which one is up to the manufacturer. It is a generic code, so it means the same on every make.
Is it safe to drive with P018C?
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 P018C fail an emissions test?
Yes, it can. P018C 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 P018C to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P018C 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.