SHOE-TRACK 8E4496 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the electrical system if a problem is suspected with the Cat Data Link or if another procedure has sent you here.Note: This procedure checks for an open circuit or for a short circuit in the Cat Data Link. If you are experiencing problems with communications between Caterpillar Electronic Technician (ET) and the Electronic Control Module (ECM), refer to Troubleshooting, "Electronic Service Tool Does Not Communicate" before you use this procedure.The Cat Data Link is the standard data link that is used by the ECM to communicate with Cat ET. The ECM communicates with Cat ET in order to share status information and diagnostic information. Cat ET can also be used to configure the ECM parameters.
Illustration 1 g01421618
Typical schematic for the Cat Data Link
The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.
Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the ECM.
Illustration 2 g01385856
Location of the ECM connectors for the Cat Data Link (typical left side engine view)
(1) J1/P1 ECM connectors
Thoroughly inspect connectors (1) and (2). Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01312112
Terminal locations at the P1 ECM connector for the Cat Data Link
(P1-8) Cat Data Link +
(P1-9) Cat Data Link −
Illustration 4 g01388995
Terminals at the customer connector that are associated with the Cat Data Link
(7) Cat Data Link +
(6) Cat Data Link −
Illustration 5 g01388996
Terminals at the service tool connector that are associated with the Cat Data Link
(Terminal G) Cat Data Link +
(Terminal F) Cat Data Link −
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the Cat Data Link.
Check the allen head screw on each ECM connector for the proper torque. Also, check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values. 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 harness and the connectors appear to be OK. Proceed to Test Step 2.
Not OK - The connectors and/or the wiring are not OK.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 original problem is resolved.STOPTest Step 2. Check for a Short Circuit
Disconnect the P1 ECM connector.
Disconnect Cat ET from the service tool connector.
Disconnect any other control modules from the Cat Data Link. Refer to the electrical schematic in order to identify other control modules on the Cat Data Link.
Measure the resistance between the points that are listed in Table 1. Be sure to wiggle the wires in the harnesses as you make each resistance measurement.
Table 1
Resistance Measurements for the Cat Data Link
Connector and