The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine start ability. If the ECM receives a engine speed signal from the camshaft position sensor (PHASE), it knows that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents battery discharging, thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn controls the fuel pump.
Disconnect "fuel level sensor unit and fuel pump" harness connector.
Check harness continuity between IPDM E/R harness connector and "fuel level sensor unit and fuel pump" harness connector.
Is the Inspection result normal?
YES >> GO TO 13.
NO >> GO TO 12. 12.DETECT MALFUNCTIONING PART
Check the following.
Harness connectors B10, E29
Harness for open or short between "fuel level sensor unit and fuel pump" and IPDM E/R >> Repair open circuit or short to power in harness or connectors.
13.CHECK FUEL PUMP GROUND CIRCUIT
Disconnect "fuel level sensor unit and fuel pump" harness connector.
Check the continuity between "fuel level sensor unit and fuel pump" harness connector and ground.
Is the Inspection result normal?
YES >> GO TO 15.
NO >> GO TO 14. 14.DETECT MALFUNCTIONING PART
Check the following.