Fuel Pump Relay - From 99MY

The fuel pump relay is fitted in the engine compartment fusebox which is situated at the front right hand side of the engine compartment. The relay is a four-pin normally open type, encapsulated in a yellow plastic housing.

The fuel supplied to the injectors from the in-tank fuel pump is controlled by the ECM via the fuel pump relay. During engine cranking, the fuel pump relay is activated by the ECM allowing the fuel system to be pressurized to 3.5 bar (52 labor.sq.in). The pump relay is then deactivated until engine start has been achieved.

Battery voltage is supplied via the engine compartment fusebox and relay activation is achieved by ground path switching through the ECM.

If the fuel pump relay should fail, the following symptoms may be observed:
- Engine stalls or will not start
- No fuel pressure at the fuel injectors

A fuel pump relay failure is likely to occur for the following reasons:
- Relay drive open circuit
- Short circuit to vehicle supply or ground
- Component failure

If the fuel pump relay should fail, the following fault codes will be generated by the ECM diagnostics, which can be retrieved by Testbook:

- P1230 - Fuel pump relay open circuit - not the fuel pump itself
- P1231 - Fuel pump relay short circuit to battery supply - not the fuel pump itself
- P1232 - Fuel pump relay short circuit to ground - not the fuel pump itself