P0231 — Fuel Pump Secondary Circuit Low
The voltage on the secondary side of the fuel pump circuit is below the expected level when the pump is commanded on. Often caused by a failed pump motor, corroded ground, or wiring fault.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Fuel pump
- Fuel pump wiring
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Fuel pump motor failed or worn
- Pump ground point corroded
- Connector pins corroded - high contact resistance
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
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
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.