P027B
Fuel Pump Module B Control Circuit Range/Performance
Fuel delivery
Generic OBD-II
High
What it means
P027B means the fuel-pump module 'B' control circuit isn't behaving within its expected range — the module commands the pump but the circuit's response is out of spec. Because this circuit governs fuel delivery, the fault can leave the engine hard to start, stalling, or short on power, so it should be treated as a potential no-start until diagnosed.
High
Can I keep driving? Because it involves fuel-pump control, fuel delivery can be unreliable — the engine may be hard to start, stall, or lack power, so treat it as a potential no-start.
Common symptoms
What you'll notice
- Check-engine light on
- Hard starting or a no-start condition
- Rough idle, stalling, or hesitation under load
- Loss of power at higher demand
Common causes
Most likely first
- Poor connection or damaged wiring in the fuel-pump module 'B' control circuitLikely
- Faulty fuel-pump relay or blown fuel-pump fuseCommon
- Failed fuel-pump (driver) moduleCommon
- Faulty fuel pump or its feedback/monitor circuitLess often
- Damaged control module (ECM/PCM) driverLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and inspect the fuel-pump module control wiring and connectors for damage or corrosion.
- Check the fuel-pump fuse and relay, and the control-circuit continuity.
- Verify the fuel-pump (driver) module supply, ground, and control signal.
- Measure fuel pressure to confirm actual pump performance.
- Replace the faulty relay, module, or pump as identified, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P027B?+
Not reliably — a fuel-pump control fault can cause a sudden stall or leave you unable to restart. Address it before longer trips.
Can I just clear P027B?+
It returns as soon as the module sees the control circuit out of range. The wiring, relay, or module fault has to be repaired.
Related codes
Often seen with P027B
Read & clear P027B 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