Fuel Pump

OPERATION

Activates the fuel pump during engine cranking and while the engine is running. When the ignition switch is set to the START position, current flows, by way of the multiport fuel injection relay coil, from the ignition switch to ground. As a result, the multiport fuel injection relay switch is switched ON, and the power for activation of the fuel pump is supplied, by way of the multiport fuel injection relay switch, from the battery to the fuel pump.






INSPECTION

While the engine is running, the engine control module switches ON the power transistor, after which current flows to the multiport fuel injection relay coil, and the power for activation of the fuel pump is supplied to the fuel pump.

When the multi port fuel injection relay switch is switched ON, battery voltage is also applied to the engine control module, and so the engine control module detects the fact that the power for activation of the fuel pump is being supplied to tne fuel pump.








Harness Inspection


Multiport Fuel Injection Relay

Fig. 1 Control Relay Test:

Fig. 1

COMPONENT TEST
1. Remove the control relay.
2. Using an ohm meter, check the resistance between the terminals as shown in FIG. 1.

Fig. 2 Control Relay Test:

Fig. 2

3. Using an ohm meter, check the resistance terminals 1 and 4, when voltage is supplied and not supplied between terminals 6 and 7 as shown in FIG. 2.

Fig. 3 Control Relay Test:

Fig. 3

4. Using an ohm meter, check the resistance terminals 2 and 4, when voltage is supplied and not supplied between terminals 6 and 8 as shown in FIG. 3
5. If not as specified, repalce multiport fuel injection relay.


Multiport Fuel Injection Relay operation and inspection can be found under ECM Power and Ground Supply Circuits. ECM Power and Ground Supply Circuits