P018B: Fuel pressure sensor B not reading plausibly
Fuel pressure sensor B circuit range/performance
Severity: Inspect soon
GM's bulletin links P018B to hesitation or stalling in hot weather on some trucks, so it should be checked rather than ignored.
It gets more serious if:
- Stop: Treat it as urgent if the engine stalls while driving, because power steering and brake assist are reduced when an engine stops.
P018B in short
P018B means the fuel pressure sensor B signal is outside its expected range or did not change as it should when the fuel pump ran. A bad sensor, its wiring or a real pressure fault can cause it. Hesitation or stalling is possible, so have it checked soon.
On GM vehicles the fuel pump control module reads a fuel pressure sensor on the feed line. The module expects the pressure to rise when the pump runs.
GM service information (read via Saab) sets P018B when the module sees less than a 30 kPa (4.4 psi) change while the pump runs, with the engine on at least 5 seconds and at least 2 gallons in the tank.
If the wiring tests good, the sensor itself is replaced. TaT adds that the sensor may be accurately reporting a real pressure fault.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Fuel pressure sensor failed or stuck
Common general cause- Why it ranks here
- GM's procedure replaces the sensor if wiring tests good.
- What would change this
- Rises if wiring is fine and pressure does not change with the pump. Falls if a gauge shows pressure changes the sensor misses.
Cause 2: Sensor wiring, ground or reference circuit fault
Common general cause- Why it ranks here
- GM's procedure tests ground, reference voltage and signal circuits first.
- What would change this
- Rises if a circuit test fails. Falls if all circuits test good.
Cause 3: A real fuel pressure problem (pump or supply)
Possible — needs testing- Why it ranks here
- TaT says the sensor may be correctly reporting abnormal pressure; GM's PIP5411A ties P018B to hot-weather hesitation and stalling.
- What would change this
- Rises if a mechanical gauge shows low or unstable pressure. Falls if pressure is normal.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Read all codes and note P2635 and any stall history.
IfP2635 is also stored, on a 2015-2016 GM full-size SUV
It meansAsk a dealer about GM PIP5411A.
IfP018B alone
It meansHave the sensor circuits tested.
Step 2: Have a shop check the sensor ground, reference and signal circuits, and compare sensor pressure with a mechanical gauge.
Warning:Fuel system tests involve pressurised fuel; leave them to a shop.
IfCircuits fail the test
It meansRepair the wiring.
IfCircuits good but sensor wrong
It meansReplace the sensor.
IfThe gauge shows real low pressure
It meansTest the pump and supply.
Symptoms
- Check engine light
- Hesitation or stalling, especially in hot weather Gets more serious: stop and have it checked.
How to fix
On your vehicle
ChevroletYour car
2015–2016 · Tahoe
Supported by vehicle dataGM PIP5411A lists hesitation or stalling at 100 F or higher with P2635 and/or P018B on the Tahoe and related models. Only the cached summary was read.
PIP5411AStatus unverified
Hesitation or stalling at 100 F or higher with P2635 and/or P018B
2015–2016tahoe, suburban · NHTSA 10083180
GM preliminary information; GM said it was working on a solution.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Related codes
P018B questions
Why does P018B appear in hot weather?
GM has reported hesitation and stalling with this code at 100 F or higher on some 2015-2016 SUVs.
Sources and review
- DTC P018B-P018D (Saab 9-4X 2011)
- GM PIP5411A: hesitation or stalling in 100 F+ weather, P2635 and/or P018B
- P018B fault code entry
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error