0338673 JOHNSON WATER TUBE

Illustration 1 g00839573
Typical schematic
Illustration 2 g01091113
P1 ECM connector (P1-29) Digital return (P1-34) Prelubrication relayTest Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF position.
Thoroughly inspect the ECM connector J1/P1. Inspect all of the other connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and the wiring for abrasion and for pinch points.Expected Result:The connectors and wiring are free of the following problems: damage, corrosion, abrasion and incorrect attachment.Results:
OK - The connectors and wiring are OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check for Active Diagnostic Codes
Connect the electronic service tool to the service tool connector.
Turn the keyswitch to the ON position.
Monitor the active diagnostic code screen on the electronic service tool. Check and record any active diagnostic codes.Note: Wait at least 15 seconds in order for the diagnostic codes to become active.Expected Result:No diagnostic codes are active.Results:
OK - No diagnostic codes are active.Repair: The problem may have been solved during the preceding inspection of the harness and connectors. The problem may be intermittent. If the problem is intermittent, refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - A 338-05 diagnostic code or a 338-06 diagnostic code is active. Proceed to Test Step 3.Test Step 3. Check for Voltage at the Prelubrication Motor
Turn the keyswitch to the OFF position.
Connect the Caterpillar Electronic Technician (ET) to the cab service tool connector J42. Start Cat ET.
Connect a voltmeter between the positive terminal of the prelubrication motor and ground.
Turn the keyswitch to the ON position. The engine should be off.
Access the override for the prelubrication system.
Enable the override for the prelubrication system.
Measure the voltage between the positive terminal of the prelubrication motor and ground.
Disable the override for the prelubrication system.
Turn the keyswitch to the OFF position. The engine should be off.
Replace all wires to the original configuration.Expected Result:The voltage is 24 3 VDC.Results:
OK - The voltage is 24 3 VDC. Proceed to Test Step 4.
Not OK - The voltage is not 24 3 VDC. Proceed to Test Step 5.Test Step 4. Check the Operation of the Prelubrication Motor
Turn the keyswitch to the OFF position.
Connect one side of a suitable piece of 10 AWG wire to the +Battery terminal.
For one second, connect the other end of the wire to the positive terminal of the prelubrication motor.Expected Result:The prelubrication motor starts while the wire is connected to the positive terminal of the prelubrication motor.Results:
OK - The prelubrication motor starts. There is a problem in the wiring harness at the prelubrication motor.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOP
Not OK - The prelubrication motor did not start.Repair: Verify that the wire to ground at the prelubrication relay has continuity to ground. If the wire to ground is OK, the problem is in the prelubrication motor. Install a new prelubrication motor. Verify that the problem is no longer present.STOPTest Step 5. Check the Output Voltage from the Prelubrication Relay
Disconnect wire 337-WH from terminal 87 of the prelubrication relay.
Connect a voltmeter between terminal 87 and ground.
Turn the keyswitch to the ON position. The engine should be off.
Access the override for the prelubrication system.
Enable the override for the prelubrication system.
Measure the voltage between terminal 87 and ground.
Disable the override of the prelubrication system.
Turn the keyswitch to the OFF position.
Replace all wires to the original configuration.Expected Result:The voltage is 24 3 VDC.Results:
OK - The voltage is 24 3 VDC. Proceed to Test Step 6.
Not OK - The voltage is not 24 3 VDC. Proceed to Test Step 7.Test Step 6. Check the Voltage to the Coil of the Pump Relay
Reconnect wire 337-WH to terminal 87 of the prelubrication relay.
Disconnect the wire from the pump relay to the prelubrication motor.
Connect a voltmeter between wire 337-WH on the pump relay and ground.
Turn the keyswitch to the ON position. The engine should be off.
Access the override for the prelubrication system.
Enable the override for the prelubrication system.
Measure the voltage between wire 337-WH on the pump relay and ground.
Disable the override of the prelubrication system.
Turn the keyswitch to the OFF position.
Replace all wires to the original configuration.Expected Result:The voltage is 24 3 VDC.Results:
OK - The voltage is 24 3 VDC.Repair: Verify that battery voltage is available to the normally open contacts of the pump relay. If voltage is not present on the normally open contacts of the pump relay, repair the wire between the pump relay and the +Battery.Verify that the wire from the pump relay to ground has continuity to ground. If the wire to ground is OK and voltage is present at the normally open contacts of the pump relay, replace the pump relay. Verify that the problem is no longer present.STOP
Not OK - The voltage is not 24 3 VDC. There is a problem in the wiring harness between the prelubrication relay and the pump relay.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 7. Check the Voltage to the Coil of the Prelubrication Relay
Disconnect wire F709-BU from terminal 86 of the prelubrication relay.
Connect a voltmeter between wire F709-BU from terminal 86 of the prelubrication relay and ground.
Turn the keyswitch to the ON position. The engine should be off.
Access the override for the prelubrication system.
Enable the override for the prelubrication system.