0436976 JOHNSON PISTON & RING ASSY., Std.

Illustration 1 g00883575
Schematic for the relay of the fuel pump
Illustration 2 g00883653
Terminal locations for the ECM connector P1Test Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect the J1/P1 ECM connector and all other connectors in the circuit. Refer to Troubleshooting, "Electrical Connectors-Inspect" for details.
Perform a 45 N (10 lb) pull test on all the wires that are associated with the circuit for the fuel pump.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM.Expected Result:All connectors, pins and sockets should be completely coupled and/or inserted and the harness and wiring should be free of corrosion, abrasion or pinch points.Results:
OK - The connectors and the wiring is good. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and the wiring.Repair: Perform the following repair:Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Perform the "Fuel Pump Relay Command Override"
Turn the keyswitch to the OFF/RESET position.
Connect the Caterpillar Electronic Technician (Cat ET) to the service tool connector.
Turn the keyswitch to the ON position.
Go to the "Fuel Pump Relay Command Override" on Cat ET.
Start the test and listen for a click from the relay for the fuel pump.Note: Do not leave the "Fuel Pump Relay Command Override" on. Avoid unnecessary cycling of the fuel pump in order to prevent the battery from discharging. The fuel pump has a 120 second timer in order to disable the test when the time expires.Expected Result: The relay activates when the "Fuel Pump Relay Command Override" is turned on.Results:
OK - The relay is working properly. Proceed to Test Step 3.
Not OK - There is a problem with the relay circuit. Proceed to Test Step 6.Test Step 3. Check the Voltage Output at the Relay
Illustration 3 g00883663
Turn the keyswitch to the OFF/RESET position.
Disconnect the wire from terminal 4 (Fuel Pump) on the relay connector.
Connect a voltage test lamp between the disconnected relay terminal and chassis ground.
Turn the keyswitch to the ON position.
Go to the "Fuel Pump Relay Command Override" on Cat ET.
Start the test and watch the voltage test lamp.Note: Do not leave the "Fuel Pump Relay Command Override" on. Avoid unnecessary cycling of the fuel pump in order to prevent the battery from discharging. The fuel pump has a 120 second timer in order to disable the test when the time expires.Expected Result:The test lamp turned on and the test lamp turned off with the "Fuel Pump Relay Command Override".Results:
OK - The relay for the fuel pump and the +battery connection to the relay for the fuel pump are OK. Reconnect the wire from the fuel pump to the terminal on the relay for the fuel pump. Proceed to Test Step 4.
Not OK - The test lamp does not turn on or the test lamp stays on. Reconnect the wire from the fuel pump to the terminal on the relay for the fuel pump. Proceed to Test Step 9.Test Step 4. Check the Resistance of the Fuel Pump
Disconnect the connector for the fuel pump.
Measure the resistance of the fuel pump.
Reconnect the connector for the fuel pump.Expected Result:Resistance should be less than 10 Ohms.Results:
OK - The resistance of the fuel pump is OK. Proceed to Test Step 5.
Not OK - The resistance of the pump is out of specification.Repair: Replace the fuel pump.Verify that the repair eliminates the problem.STOPTest Step 5. Check the Supply Voltage to the Fuel Pump
Illustration 4 g00883621
Disconnect the fuel pump.
Turn the keyswitch to the ON position.
Proceed to the "Fuel Pump Relay Command Override" on Cat ET.
Activate the relay for the fuel pump.Note: The diagnostic override will only activate the relay for 120 seconds.
Use signal reading probes to measure the voltage across terminal 1 (Signal) and terminal 2 (Ground) of the connector for the fuel pump.Expected Result:The supply voltage should be greater than 22.0 VDC.Results:
OK - The relay is supplying the proper signal to the fuel pump, but the fuel pump is not working.Repair: Replace the fuel pump.Verify that the repair eliminates the problem.STOP
Not OK - The fuel pump is not receiving the correct signal. Proceed to Test Step 6.Test Step 6. Check the Resistance of the Relay
Illustration 5 g00883651
Relay Terminals
Turn the keyswitch to the OFF/RESET position.
Unplug the relay for the fuel pump.
Measure the resistance between terminal 86 (Fuel Pump Relay (Signal)) and terminal 85 (Solenoid Return) of the relay.Expected Result:The resistance should be between 250 Ohms and 500 Ohms.Results:
OK - The resistance is between 250 Ohms and 500 Ohms. Proceed to Test Step 7.
Not OK - The relay is faulty.Repair: Replace the relay.Verify that the repair eliminates the problem.STOPTest Step 7. Check the Signal Voltage to the Relay
Illustration 6 g00883664
Unplug the relay for the fuel pump.
Turn the keyswitch to the ON position.
Proceed to the "Diagnostic Overrides" screen on Cat ET.