PISTON 4397661 - Caterpillar

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 the Cat® 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. This information will not be available if communication fails between the ECM and Cat ET.
Illustration 1 g01390276
Schematic for the Cat Data Link
Illustration 2 g01380568
Connector locations for the Cat data link (rear engine view)
(1) P1 ECM connector
(2) Customer Connector
Illustration 3 g01380580
Connector locations for the Cat data link (top rear engine view)
(2) Customer Connector
(3) Service tool connector
Illustration 4 g01312112
Terminal locations at the P1 ECM connector that are associated with the Cat Data Link
(P1-8) Cat Data Link +
(P1-9) Cat Data Link −
Illustration 5 g01367380
Terminal locations at the Customer Connector that are associated with the Cat Data Link
(Terminal 6) Cat Data Link −
(Terminal 7) Cat Data Link +
Illustration 6 g01365685
Terminal locations at the service tool connector that are associated with the Cat Data Link
(D) Cat Data Link +
(E) Cat Data Link −
Table 2
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Remove electrical power from the ECM.
B. Thoroughly inspect connectors (1), (2), and (3). Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the Cat Data Link.
D. 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.
Connectors, Pins, and Sockets
Result: The harness and the connectors appear to be OK. Proceed to Test Step 2.
Result: The connectors and/or the wiring are not OK.
Repair: Repair