5031255 JOHNSON *BEARING

Illustration 1 g01183520
Schematic for the start relayTest Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01183529
J1/P1 ECM connector (typical left side engine view)
Thoroughly inspect the J1/P1 ECM connector, the connector for the keyswitch, the connector for the start relay, and any other connectors in the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01183521
P1 terminal locations for the start relay (P1-10) Start relay (P1-64) Keyswitch (start) (P1-67) Start relay return (P1-70) Keyswitch (run)
Perform a 45 N (10 lb) pull test on each of the wires in the connectors that are associated with the circuit.
Check the torque of the allen head screws for each of the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for corrosion, for abrasion, and for pinch points back to the ECM.Expected Result:All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The wiring and the connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the wiring and/or the connectors.Repair: Repair the connectors and/or the wiring. Replace parts, if necessary. 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. Check for Active Diagnostic Codes
Turn the keyswitch to the OFF position.
Connect Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Turn the keyswitch to the ON position.
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active.
Turn the keyswitch to the START position.
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active.
Look for these codes:
444-05
444-06
Turn the keyswitch to the START position in order to verify whether the starting motor cranks the engine.
Turn the keyswitch to the OFF position.Expected Result:There are no active diagnostic codes and the engine cranks.Results:
OK - No diagnostic codes are active and the starting motor cranks the engine.Repair: The problem appears to be resolved. The problem is probably related to a faulty connection in the harness or at a connector. Carefully inspect the connectors and the wiring that is related to the start circuit. Ensure that all connections are tight and ensure that all wires are crimped correctly. Refer to Troubleshooting, "Electrical Connectors - Inspect" for information that relates to the proper troubleshooting of intermittent electrical problems.STOP
444-05 - There is an active 444-05 diagnostic code. Proceed to Test Step 3.
444-06 - There is an active 444-06 diagnostic code. Proceed to Test Step 5.
Engine Will Not Crank - There are no active diagnostic codes, but the engine will not crank. Proceed to Test Step 7.Test Step 3. Create a Short Circuit at the Harness Connector for the Start Relay
Turn the keyswitch to the OFF position.
Disconnect the connector for the start relay.
Fabricate a jumper wire that is long enough to connect across the terminals at the connector for the start relay. Crimp connector pins to each end of the jumper wire.
Install the jumper wire across the terminals at the connector for the start relay.
Turn the keyswitch to the ON position.
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active.
Turn the keyswitch to the START position.
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active.
Turn the keyswitch to the OFF position. Remove the jumper wire from the connector for the start relay. Connect the connector.Expected Result:There is an active 444-06 diagnostic code.Results:
OK - A 444-06 code became active when the wires were short circuited at the connector for the start relay.Repair: The wiring between the start relay and the ECM is OK. The open circuit is in the relay. Replace the start relay. Clear any diagnostic codes. Verify that the problem is resolved.STOP
Not OK - A 444-05 code remained active when the wires were short circuited at the connector for the start relay. Proceed to Test Step 4.Test Step 4. Create a Short Circuit at the ECM
Turn the keyswitch to the OFF position.
Disconnect the J1/P1 ECM connectors.
Fabricate a jumper wire that is long enough to connect across the terminals at the ECM connector. Crimp connector sockets to each end of the jumper wire.
Remove terminal P1-10 (start relay) and terminal P1-67 (start relay return) from the ECM connector. Install the jumper wire into the terminal locations for the start relay.
Connect the J1/P1 ECM connectors.
Turn the keyswitch to the ON position.
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active.
Turn the keyswitch to the START position.
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active.
Turn the keyswitch to the OFF position.
Remove the wire jumper. Return all wiring to the original configuration.Expected Result:There is an active 444-06 diagnostic code.Results:
OK - A 444-06 became active when the jumper was installed at the ECM connector. The ECM is operating correctly.Repair: There is an open circuit in the harness between the ECM connector and the connector for the start relay. Repair the circuit or replace the harness. Verify that the problem is resolved.STOP
Not OK - A 444-05 remained active when the jumper was installed at the ECM connector.Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM" for the correct procedure. Verify that the problem is resolved.STOPTest Step 5. Create an Open Circuit at the Harness Connector for the Start Relay
Turn the keyswitch to the OFF position.
Disconnect the connector for the start relay.