KlaroFault codeP0231
SEVEREFuel Pump Secondary Circuit Low
What this code means
Fuel Pump Secondary Circuit Low.
P0231 is a generic code: it means the same thing on every make. P0231 belongs to family P02xx — Injector circuit. Its page explains how to read a code and groups all its codes by part.
Type of fault
The control unit reads a voltage on this circuit below its expected range. Usual causes: a wire shorted to ground or broken, a corroded or loose connector, or the component itself. Check the wiring and connector before replacing the part — that is where many of these faults turn out to be.
Fuel pump
The fuel pump, usually inside the tank, sends fuel to the engine. The control unit switches it on through a relay or a control module, sometimes at several speeds, and may check its circuit.
What you notice
Hard starting, the engine cutting out under load, loss of power at high speed, or no start at all if the pump stops.
How to check it
Check the pump's fuse and relay first, then its connector, often on top of the tank under the rear seat or the boot floor. With ignition on, you should hear the pump run for a second or two. Klaro's fuel pressure reading, when the car reports it, shows whether pressure holds under load.
Watch it live in Klaro
With an OBD2 adapter plugged in, these live readings show the part at work, when your car reports them:
- Fuel pressure
- Fuel rail pressure (absolute)
- Fuel rail absolute pressure
What to do
Have it checked promptly. An injection, fuel-supply or boost fault can cost power, cause misfires and eventually damage the engine or the catalytic converter. If the light is flashing or the engine is overheating, stop driving.
Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →
How to read this code
- PPowertrain
- 0standardised code
- 2Injector circuit
- 31P0231
