Fuel Pump B Low Flow/Performance
The second fuel pump runs but does not deliver expected volume or pressure. Worn pump, restricted filter, or leaking pressure regulator.
Affected components
- Fuel pump b
- Fuel filter
- Fuel pressure regulator
Common causes
- High likelihood: Worn impeller reduces volumetric efficiency
- Medium likelihood: Restricted in-tank or in-line fuel filter
- Medium likelihood: Pressure regulator leaks back to tank
Possible 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
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.