3C8-03123-0 Nissan FLOAT CHAMBER (LOWER

Table 1
Diagnostic Codes for the EFLP Relay
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
1075-5 3666-5 Engine Electric Lift Pump for Engine Fuel Supply : Current Below Normal The Electronic Control Module (ECM) detects the following conditions:
There are no active 168 diagnostic codes.
The ECM is not attempting to power the relay.
The ECM has been powered for at least 2 seconds.
There is a low current condition in the EFLP relay circuit for more than 2 seconds.
The warning light will come on. The diagnostic code will be logged.
The ECM is unable to activate the relay for the EFLP. The EFLP will not operate or the EFLP will operate all the time. The engine will not operate.
1075-6 3666-6 Engine Electric Lift Pump for Engine Fuel Supply : Current Above Normal The ECM detects the following conditions:
There are no active 168 diagnostic codes.
The ECM is attempting to power the relay.
The ECM has been powered for at least 2 seconds.
There is a high current condition in the EFLP relay circuit for more than 2 seconds.
The warning light will come on. The diagnostic code will be logged.
The ECM is unable to activate the relay for the EFLP. The EFLP will not operate or the EFLP will operate all the time. The engine will not operate.
The ECM will continue to attempt to activate the relay. If the current is OK for 6 seconds, then the diagnostic code will be cleared. The following background information is related to this procedure:The EFLP is used to provide positive fuel pressure to the high-pressure fuel pump. When the keyswitch is turned to the ON position, the ECM will activate the EFLP. If the engine is not running, the ECM will deactivate the EFLP after 2 minutes.
Illustration 1 g06102446
Schematic for the Electric Fuel Lift Pump (EFLP) relay
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position.
B. Thoroughly inspect the connectors between the EFLP relay and the engine ECM. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the EFLP relay.
D. Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in).
E. Check the harness and wiring for abrasion and for pinch points from the injectors to the ECM.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair:Repair any faulty connectors or replace the wiring harness. Ensure that all the seals are properly in place and ensure that the connectors are correctly coupled.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points.
Proceed to Test Step 2.
2. Check for Active Diagnostic Codes
A. Connect the electronic service tool to the diagnostic connector.
B. Turn the keyswitch to the ON position. Do not start the engine.
C. Make a note of any active diagnostic codes.
D. Wait for at least 2 minutes for the Electric Fuel Lift Pump (EFLP) to deactivate. Make a note of any active diagnostic codes.
Diagnostic codes
Result: Diagnostic code 1075-5 or 3666-5 is active when the EFLP is switched off.
Proceed to Test Step 3.
Result: Diagnostic code 1075-6 or 3666-6 is active when the EFLP is switched on.
Proceed to Test Step 5.
Result: An active diagnostic code or a recently logged diagnostic code was not displayed. There may be a fault with the switched power circuit for the EFLP. The ECM does not monitor the status of this condition.
Proceed to Test Step 7.
3. Create a Short Circuit at the EFLP Relay
A. Turn the keyswitch to the OFF position.
B. Disconnect the harness connector for the Electric Fuel Lift Pump (EFLP) relay.
C. Fabricate a jumper wire that is 150 mm (6 inch) long.
D. Use the jumper wire to connect Test Point 1 to Test Point 2 on the harness connector for the EFLP relay. Refer to Illustration 1. Refer to the appropriate electrical schematic.
E. Turn the keyswitch to the ON position. Do not start the engine.
F. Use the electronic service tool to check for an active 1075-6 or 3666-6diagnostic code.
G. Wait for at least 2 minutes for