ACTUATOR-ROCKER 3E9326 - Caterpillar

Illustration 2 g03342141
View of the pin location on the P1 connector for the fuel lift pump relay
(53) Fuel lift pump relay
Table 1
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position
B. Check the fuses.
C. Check the harness for abrasion and pinch points from the relay back to the ECM and from the relay back to the battery.
D. Check the harness for abrasions and pinch points from the fuel lift pump back to the relay.
E. Thoroughly inspect the relay and the connector for the relay.
F. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the fuel lift pump relay.
Loose connector or damaged wire
Result: There is a fault with the harness and connectors
Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are correctly connected. Replace any blown fuses.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness and connectors are free of corrosion, abrasion, and pinch points. The fuses are OK.
Proceed to Test Step 2.
2. Override the Fuel Lift Pump Relay
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position.
D. Use the electronic service tool to activate the "Engine Fuel Supply Lift Pump Relay Override".
Note: The "Engine Fuel Supply Lift Pump Relay Override" activates the fuel lift pump relay for 10 seconds.
E. Turn the keyswitch to the OFF position.
Fuel lift pump
Result: The fuel lift pump operates when the "Engine Fuel Supply Lift Pump Relay Override" is activated. The fuel lift pump relay circuit is operating correctly at this time.
If there is an intermittent fault, refer to Troubleshooting, "Electrical Connectors - Inspect" in order to identify the fault.
Result: The fuel lift pump does not operate when the "Engine Fuel Supply Lift Pump Relay Override" is activated.
Proceed to Test Step 3.
3. Check the Application Wiring for a Short Circuit
A. Turn the keyswitch to the OFF position.
B. Disconnect the fuel lift pump relay.
C. Turn the keyswitch to the ON position.
D. Use a suitable multimeter to measure the voltage between the following points:
Test Point A on the harness connector for the relay and a suitable ground
Test Point D on the harness connector for the relay and a suitable ground
E. Turn the keyswitch to the OFF position.
11 V to 14 V
Result: The voltage is not within the expected range. The fault is in the battery supply wiring to the fuel lift pump relay.
Replace the faulty wiring. Reconnect the fuel lift pump relay.
Result: The measured voltage is within the expected range.
Proceed to Test Step 4.
4. Check the Wiring Between the Relay and the ECM
A. Turn the keyswitch to the OFF position.
B. Disconnect the fuel lift pump relay. Disconnect the P1 connector from the ECM.
C. Use a suitable multimeter to measure the resistance between Test Point B on the harness connector for the