Fuel Lift Pump Electrical Circuit

When the key is first turned ON without the engine running, the control module turns the fuel lift pump relay ON during the glow plug cycle. This builds up the fuel pressure quickly. If the engine does not start after the glow plug cycle, the control module shuts the fuel lift pump OFF and waits for the engine RPM. As soon as the engine is cranked, the control module turns the relay ON and runs the fuel lift pump.

For the location of the fuel pump relay, refer to Engine Controls Components. For diagnosis of the lift pump electrical circuit, refer to Fuel Pump Electrical Circuit Diagnosis. Component Tests and General Diagnostics