just had the ORRS back after a week in garage. In for few little jobs, came out virtually rebuilt ! Well, £1800 worth of work, of which £1200 was parts.

After an engine management ECU update, the code P0231-00 displayed but didn't bring on the engine light. I know that it says there is an electrical fault of some sort on fuel pump, but anyone know the likely cause. Electrician looked at it all day and found nothing. Because the light isn't coming on, they say it should be OK . . . . . but . . . I'd rather know what may be causing it  RR Sport Supercharged Vesuvius Orange 4.2 V8 First edition

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P0231 - Fuel Pump Secondary Circuit Low

Possible causes
- Blown Fuel Pump fuse
- Open Fuel Pump Monitor Circuit
- Faulty Fuel Pump Relay
- Damaged Engine Control Module (ECM)

When is the code detected?
The code will be set if a low voltage on the control circuit of the fuel pump relay is detected by the ECM.

P0231 Description

The Engine Control Module (ECM) provides ignition positive voltage to the coil side of the fuel pump relay. When the ignition switch is first turned ON, the ECM energizes the fuel pump relay, which applies power to the fuel pump. The ECM enables the fuel pump relay as long as the engine is cranking or running, and crankshaft reference pulses are received. If no crankshaft reference pulses are received, the ECM de-energizes the fuel pump relay after 2 seconds. The ECM monitors the voltage on the fuel pump relay control circuit.

thanks. Wouldn't any of the above cause the engine management light on the dash to light up ? I'm assuming that if it doesn't, then the fault isn't critical or corrects itself  RR Sport Supercharged Vesuvius Orange 4.2 V8 First edition

Prefer RR Vouge S/C but they don't do Orange !

I would imagine any of the possible causes listed above would cause a non-start issue.

The only thing I can think of is a high resistance on one of the pump wires...
It may also be a weak battery, causing low volts on startup, but I imagine the electrician would have checked the battery was OK

Has this issue only started since the software update?

No, it's always been there. I have had problems starting in the past, twice actually. Well, the car started but wouldn't accelerate when in gear. Lasted a few minutes then back to normal. So may be something intermittent? Since yesterday, no problems. Travelling 200 miles today - so that should 'test' it out  RR Sport Supercharged Vesuvius Orange 4.2 V8 First edition

Prefer RR Vouge S/C but they don't do Orange !

It may be an underlying issue, just waiting to become a permanent fault...

I have seen fuel pump wiring issues, both in the O/S/F wheelarch, and above the fuel tank itself...