What it means
Fuel pump module B control 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
- The engine or gearbox may go into limp mode
How it works
Fuel pump module B is the second pump module in systems that use more than one pump or module. The control module monitors its electrical control signal and sets this code when the signal is higher than expected, which can result from a short to battery voltage; it does not alone show that the pump is delivering too much fuel.
Common causes
Most likely first.
- Wiring shorted to battery
- 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 module B control or fuel-pressure information to identify when the high signal occurs.
- Inspect the module B harness and connector for pinched insulation, chafing, water intrusion, or damaged terminals.
- Check the module B control circuit for a short to battery voltage using the vehicle wiring diagram and the manufacturer's procedure.
- Check connector contact and module supply or ground connections, comparing circuit readings with the manufacturer's specification.
- If the external circuit is sound, test module B and its control input before replacing the module.
Common fixes
- Repair a pinched or chafed control wire shorted to a power source.
- Repair corroded, loose, or damaged module B connector terminals.
- Secure or reroute wiring away from a battery-voltage source.
- Replace module B only if testing confirms an internal fault.
Can I keep driving?
Avoid heavy loads and unnecessary trips if starting or fuel delivery is unreliable; the fault can lead to stalling or power loss. Stop driving if the engine stalls or loses power in a way that makes the vehicle 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.