P018C
Fuel Pressure Sensor B Circuit Low
Fuel & air metering (fuel pressure)
Generic OBD-II
High
What it means
P018C means the 'B' fuel pressure sensor is sending a signal that's too low — usually a short to ground, an open circuit, or a failed sensor rather than a true loss of fuel pressure. Because the ECM relies on this reading to manage the fuel system, some vehicles will limit power or enter limp mode until the sensor circuit is repaired.
High
Can I keep driving? Drivable but have it checked soon — losing a fuel-pressure signal can push the engine into reduced-power/limp mode on some vehicles.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power or limp/failsafe mode
- Hesitation or rough running under load
- Fuel pressure reads at or near zero on a scan tool
Common causes
Most likely first
- Faulty fuel pressure sensor 'B'Likely
- Signal circuit shorted to ground or openCommon
- Corroded or loose connector at the sensorCommon
- Poor sensor ground or reference voltageLess often
- Faulty ECM (rare — confirm sensor and wiring first)Less often
How to diagnose & fix
Work through it in order
- Read the live fuel-pressure 'B' value — a circuit-low fault typically shows an implausibly low or zero reading.
- Inspect the sensor connector and harness for a short to ground, an open, or corrosion.
- Check the sensor's 5V reference and ground with the key on.
- Back-probe the signal wire to decide whether the sensor or the wiring is at fault.
- Replace the fuel pressure sensor if it reads low with good wiring, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P018C?+
Short trips, yes, but the engine may limit power or enter limp mode because it can't trust the fuel-pressure reading. Get the sensor circuit diagnosed before extended driving.
Can I just clear P018C?+
It returns as soon as the ECM sees the low signal again. Repair the sensor or wiring before clearing.
Related codes
Often seen with P018C
Read & clear P018C yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX