Fuel Pump: Testing and Inspection

SYSTEM DESCRIPTION
The ECM activates the fuel pump for several seconds after the ignition switch is turned on to improve engine startability. If the ECM receives a 180 ° signal from the camshaft position sensor, it knows that the engine is rotating, and causes the pump to perform. If the 1800 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.




CONSULT Reference Value in Data Monitor Mode




ECM Terminals and Reference Value
Specification data are reference values and are measured between each terminal and 43 (ECM ground).







WIRING DIAGRAM

1 CHECK OVERALL FUNCTION:

2 CHECK POWER SUPPLY:

3 DETECT MALFUNCTIONING PART:

4 CHECK POWER GROUND CIRCUIT:

5 DETECT MALFUNCTIONING PART:

6 CHECK OUTPUT SIGNAL CIRCUIT:

7 DETECT MALFUNCTIONING PART:

8 CHECK FUEL PUMP:

9 CHECK FUEL PUMP:

10 CHECK INTERMITTENT INCIDENT:

DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION







FUEL PUMP RELAY
Check continuity between terminals 3 and 5.
If NG, replace relay.




FUEL PUMP
1. Disconnect fuel pump harness connector.
2. Check resistance between terminals 1 and 2.
Resistance: 0.2 - 5.0 Ohms [at 25 °C (77 °F)]
If NG, replace fuel pump.