Fuel Pump: Testing and Inspection
Fuel Pump Circuit CheckDescription
SYSTEM DESCRIPTION
System Description:
The ECM activates the fuel pump for 1 second 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.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the fuel tank.
Diagnosis Procedure
Step 1-2:
Step 3-5:
Step 6-8:
Step 9-12:
Component Inspection
FUEL PUMP
1. Disconnect "fuel level sensor unit and fuel pump" harness connector.
2. Check resistance between "fuel level sensor unit and fuel pump" terminals 1 and 3.
Resistance: 0.2 - 5.0 ohms [at 25 °C (77 °F)]