What it means
Fuel pressure sensor B signal voltage above expected range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Fuel pressure sensor B measures pressure at its assigned point in the fuel system and reports it to the engine control module. P018D sets when the sensor signal is above the expected electrical range; an open signal circuit or a wire contacting battery voltage can produce that condition.
Common causes
Most likely first.
- Signal wire open
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
How to diagnose it
- Review freeze-frame data and live pressure sensor B readings for an implausibly high or fixed value and note the conditions when it appears.
- Locate sensor B using service information and inspect its connector and harness for an open, corrosion, pin damage, or contact with a power source.
- Check the signal circuit for continuity and for a short to voltage, following the manufacturer's wiring test procedure.
- Verify sensor B's power and ground connections and compare circuit readings with the manufacturer's specification.
- If the wiring and connections are sound, test fuel pressure sensor B and replace it only if its output is out of specification.
Common fixes
- Repair an open in the sensor B signal wire.
- Separate and repair a signal wire pinched against a voltage source.
- Clean or replace corroded or damaged connector terminals.
- Replace fuel pressure sensor B if it produces an excessive signal with a sound circuit.
Can I keep driving?
Treat hard starting, stalling, or reduced power as a reason to avoid driving in fast traffic or under heavy load. Stop if the engine stalls or loses enough power to make continued driving unsafe.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.