Ford Focus>> Power supply system>> Search of malfunctions of the fuel pump
The relay of the fuel pump turns on the fuel pump, and fuel moves to nozzles. The safety relay works, when the engine does not work, and ignition is included (the control unit does not receive signals about number of turns). This relay is switched off in the control unit via the safety switch and interrupts pump power supply. So, for example, in case of failure gasoline cannot arrive in the engine. Check of the fuel pump — is work most likely for the service centers. In this regard for search of mistakes we will be limited to the following items:
- switch off ignition;
- disconnect топливопровод submitting highway on the distributor, thus prepare rags for the poured-out gasoline;
- already at the switched-off engine there can be a gasoline quantity as the system is under pressure;
- include for short time ignition, not including a starter;
- if the pump does not start to work, check once again a safety lock or the safety relay;
- if fuel does not arrive, check the pump relay;
- at serviceable relays the fuel pump should earn;
- otherwise uncover under a back seat and carefully knock on the pump case with a small hammer — sometimes helps;
- check correctness of connection of wires to the fuel pump;
- if the pump does not work, check tension by means of the diode bridge (the usual control lamp can damage the control unit). Do not forget to include ignition before;
- if tension is normal, means the pump is damaged or there is a break in a chain. It is necessary to replace the pump with the new.

Fig. 188. Design of the fuel pump: 1 — the bringing highway; 2 — the reduktsionny valve; 3 — the filter case; 4 — the fuel pump with the electric drive; 5 — the return valve; 6 — the submitting highway

- if the pump works, but on топливопроводу fuel does not arrive, means the fuel filter or itself топливопровода (fig. 188) is hammered .