Fuel Pump: Testing and Inspection

SYSTEM DESCRIPTION




Fuel pump ON-OFF control
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine start-up. If the ECM receives a 120° signal from the camshaft position sensor, it knows that the engine is rotating, and causes the pump to activate. If the 120° signal is not received when the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents the battery from 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.




WIRING DIAGRAM







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 (4) and (6).

Resistance: 0.2 - 5.0 Ohms at 25°C (77°F)

If NG, replace fuel pump.6/27

FPCM
With Consult
1. Start engine and let it idle.










2. Perform "FPCM" in "ACTIVE TEST" mode with CONSULT.




3. Make sure of the following.
4. If NG, replace FPCM.

OR

Without Scan Tools
1. Start engine and warm it up sufficiently.
2. Turn ignition switch "OFF" and wait for at least 5 seconds.
3. Start engine and let it idle.




4. Check voltage between terminals (1) and (2). The voltage should be within each of following ranges at least one time within 60 seconds of starting engine.




5. If NG, replace FPCM.