Fuel pump control unit
There is a problem with my 2005 Rover 45. I failed to find a code reader to sort out the problem for myself, so had the fault diagnosed by the RAC, as I was concerned about using the car, and had it confirmed by my local garage, although they could not dig any deeper. The fault logged is ‘P0251 fuel pump control unit, signal out of range, too high’. Both the RAC and the garage confirmed it was OK to use the car, which I still do, even though the MIL is still on.
The car starts straight away and runs perfectly. I have checked all the sensors, changed the filters, completed an in-depth service and checked for corrosion in the connectors. The only fault I have found is that the maximum engine rpm is 4000 against a normal of nearer 6000 in the past.
It appears that the car is one of the last facelift models of the 45 Dti issued in 2005. As very few were made, there are no details recorded about them and hence the confusion. David Jones
The code ‘P0251’ is a generic code for the injection pump fuel metering control, circuit malfunction. This gives three areas that may be causing the problem: the fuel pump, the wiring loom or the ECU.
The first area to check would be the wiring loom between the fuel pump and ECU. Ensure that the terminals within the plugs are clean and dry and are not displaying any signs of corrosion. Checking the loom between the ECU and pump using an ohmmeter may highlight a problem within the loom.
If no problems can be found within the wiring loom, the next cheapest option may be to get the ECU tested. Either
ecutesting.com or bba-reman.com can carry this out and will give you a definitive answer. This will, of course, require the unit to be sent away, taking the Rover off the road for a few days.
One other possibility that would be worth checking out is the timing belt and injection pump drivebelt. If either of these belts is slack, it could also cause the symptoms you have.
If these two avenues do not resolve the problem, the final component left is the fuel pump itself, which would need to be tested by a specialist and possibly rebuilt.