PLUG 5I7525 - Caterpillar

Illustration 1 g00793613
SchematicTest Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect ECM connector J1/P1 and machine connector J3/P3. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.Note: Refer to the Electrical System Schematic for further information about the machine wiring.Expected Result:All connectors, pins, and sockets should be completely inserted and coupled. The harness and wiring should be free of corrosion, abrasion, and pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 2. Check for Shorts in the Harness
Illustration 2 g00715687
ECM connector P1
Disconnect ECM connector J1/P1.
Disconnect all modules from the CAT Data Link.
Disconnect ET from the service tool connector.
Measure the resistance between P1:3 (CAT Data Link -) and P1:9 (Cat Data Link +).
Measure the resistance between P1:9 (Cat Data Link +) and chassis ground.
Measure the resistance between P1:3 (CAT Data Link -) and chassis ground.Expected Result:The resistance should be greater than 20,000 Ohms for each measurement.Results:
OK - Proceed to Test Step 3.
Not OK - There is a short circuit in the harness or connectors.Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 3. Check the Resistance Through the Harness
Illustration 3 g00715687
ECM connector P1
Use a suitable piece of wire to short J42:D (CAT Data Link +) and J42:E (CAT Data Link -) at the service tool connector.
Measure the resistance between P1:9 (CAT Data Link +) and P1:3 (CAT Data Link -).
Measure the resistance across the CAT Data Link at the other modules.Expected Result:The resistance should be less than 10 Ohms for each measurement.Results:
OK - The CAT Data Link is OK.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent. Stop.
Not OK - There is an open circuit or excessive resistance in the harness or connectors.Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.