HARNESS AS 1339992 - Caterpillar

Illustration 1 g02412237
Schematic of the J1939 (CAN) Data Link Network connections.This diagnostic code is associated with communication between the Machine ECM and the Machine Security System (MSS) key reader conducted over the J1939 (CAN) Data Link. The FMI 09 diagnostic code means that the Machine ECM has lost communication with the MSS key reader. The possible causes of this diagnostic code are listed below:
An open or a poor connection in the J1939 (CAN) Data Link circuit.
The MSS key reader has failed.
The Machine ECM has failed. This situation is unlikely.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure and in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure. Test Step 1. CHECK THE DATA LINK CIRCUIT FOR AN OPENNote: The two CAN resisters are connected in parallel in the CAN circuit. Each resister is a 120 ohm resister. When a resistance measurement is taken between the data link circuits, the resistance should be approximately 60 ohms.
Turn the key switch and the disconnect switch to the OFF position.
Refer to the illustration for J1939 (CAN) system connections. Disconnect the machine harness connectors with J1939 (CAN) connections from each component in the system except for the two CAN resisters. Leave the CAN resisters connected to the system.
Inspect each machine harness connector for J1939 (CAN) contacts that may be dirty, loose, or corroded. Ensure that all J1939 (CAN) connections are secured in the connector, the contacts are clean, and the contacts are in good condition.
At the disconnected harness connector for the MSS key reader, connect a jumper wire between contact 3 (wire F711-GN) and contact 4 (wire F712-GY).
At the harness connector J2 for the Machine ECM, measure the resistance between contact J2-67 (wire F711-GN) and contact J2-68 (wire F712-GY).Expected Result:The resistance measurement is approximately 60 ohms.Results:
OK - The resistance measurement is approximately 60 ohms. The CAN data Link circuit between the MSS key reader and the Machine ECM is not open. Proceed to Test Step 2.
NOT OK - The resistance measurement is greater than 60 ohms.Repair: There is an open or a bad connection in the CAN data link circuit in the machine harness. Refer to the Electrical System Schematic of the machine. Locate and examine all of the machine harness connections that are involved in the data link circuit. Check each wire section from connector to connector for an open or a bad connection. Ensure that all connections are clean, secure and in good condition. Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE STATUS OF THE DIAGNOSTIC CODE
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the data link circuit.
Reconnect all harness connectors. Make sure that the connectors are fully seated. Observe that the