Faulty fuel pressure sensor B; Damaged, chafed or corroded wiring to the sensor (open circuit, short to earth or short to supply); Poor connection at the sensor or control unit connector (corrosion, bent or loose pins); Sensor supply voltage or reference earth fault; Genuine fuel pressure problem such as a weak pump, blocked filter or leaking regulator that makes the reading implausible; Fault inside the engine control unit.

P018A

Fuel Pressure Sensor B Circuit.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
1: AreaFuel and air metering
8A: FaultThe specific fault in that area

What it means

P018A is the generic code for a fault in the Fuel Pressure Sensor B circuit. The engine control unit has seen a signal from the second fuel pressure sensor that is outside the expected range, or an electrical fault such as an open or short circuit. Which part of the fuel system sensor B monitors (low-pressure feed or high-pressure rail) depends on the vehicle and engine, so check the manufacturer's information.

Symptoms

Engine warning light on
Hard starting or long cranking
Rough idle or misfire
Hesitation or loss of power under load
Engine running in limp mode with reduced power
Intermittent stalling

Possible causes

Faulty fuel pressure sensor Blikely
Damaged, chafed or corroded wiring to the sensor (open circuit, short to earth or short to supply)likely
Poor connection at the sensor or control unit connector (corrosion, bent or loose pins)likely
Sensor supply voltage or reference earth faultpossible
Genuine fuel pressure problem such as a weak pump, blocked filter or leaking regulator that makes the reading implausiblepossible
Fault inside the engine control unitrare

How to diagnose

Read all stored and pending codes and note any other fuel pressure or fuel system codes, then review the freeze frame data.
Inspect the sensor, its connector and the wiring for damage, fuel contamination, corrosion, chafing or heat damage.
Check the live fuel pressure reading from sensor B against sensor A (if fitted) and against the expected value at key on, idle and under load.
Measure the sensor supply voltage, reference earth and signal voltage at the connector against the manufacturer's specification.
Test the wiring for continuity and for shorts to earth or supply between the sensor and the control unit.
Check actual fuel pressure with a suitable mechanical gauge or approved procedure to see whether the sensor or the fuel system is at fault.
Check fuel filter condition and fuel pump delivery, following the manufacturer's procedure for your model.
Clear the code after repair and road test to confirm it does not return.

How to fix

Replace the fuel pressure sensor B if its readings are wrong when supply and wiring are good.
Repair or replace damaged wiring and fix any short or open circuit.
Clean or repair the connector terminals, or replace the connector if the pins are damaged or corroded.
Correct any supply or earth fault found on the sensor circuit.
Repair the fuel system fault, such as a failing pump, blocked filter or faulty regulator, if actual pressure is wrong.
Replace or repair the control unit only after all other causes are ruled out and the manufacturer confirms the fault.

Can I keep driving?

Medium severity

The car may be driveable, but it could run poorly, enter limp mode or stall, so get it checked soon. If it stalls, loses power badly or smells of fuel, stop driving and have it inspected.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.