COUPLING 0995534 - Caterpillar

Illustration 1 g01042502
Schematic of the harness code receptacleThis diagnostic code is associated with the harness code receptacle. This diagnostic code is recorded when the Power Train/Chassis Electronic Control Module (ECM) receives information from the Caterpillar Monitoring System. The harness code information has changed while the machine is running. This information is not correct.
Table 1
Troubleshooting Chart for Harness Codes (1)    
Connector Contact for the Main Display Module    31    3    12    22    16    Unused    
Wire Identification     270-BK     271-BK     272-BK     273-BK     274-BK     201-BK    
Contacts for the Harness Code Plug (2)     1     2     3     4     5     6    
   
Machine Code     Specified Status    
41     O (3)     G (4)     G     O     G     G    
( 1 ) The main display module is in the Harness Code Mode (Mode 1).
( 2 ) For machines without a harness code plug, permanent harness code connections are in the machine harness.
( 3 ) Open status
( 4 ) Grounded statusBefore you perform this procedure, determine the proper machine code. The main display module must have the correct part number for the particular machine. If the machine code is not shown correctly, this procedure determines the component that is malfunctioning. This failure could be caused by a failure in the Caterpillar Monitoring System display, a wrong harness code receptacle or a harness that has failed. Note: The harness code and the machine code are similar terms. The codes describe the particular machine. The harness code is the status (open or ground) of the six harness code inputs (connector contacts 3, 6, 12, 16, 22 and 31). The Caterpillar Monitoring System ECM assigns a number to a machine. This number is the machine code. The machine code is shown during harness code mode. Each machine model has a specific harness code.Note: The following procedure checks for incorrect harness codes on the inputs for the Caterpillar Monitoring System ECM. Compare the status of the harness code that is found in the test "Determine the machine code" to the status at the inputs for the Caterpillar Monitoring System display. The table identifies the connector contacts and wire identification of the harness code circuits. Contacts that are specified as grounded contacts should be checked for opens in the harness. Contacts that are specified as open contacts should be checked for shorts in the harness.System Response:The identification code from the Caterpillar Monitoring System has changed. This would indicate an impending failure that is related to the harness code inputs for the Caterpillar Monitoring System. If the diagnostic code remains active, cycle the key start switch. This allows the ECM to receive the signal for the identification code from the Caterpillar Monitoring System.Test Step 1. CHECK FOR OPENS
Turn the battery disconnect switch to the OFF position.
Disconnect the machine harness from the Caterpillar Monitoring