SEAL-O-RING 6V5134 - Caterpillar

Use this procedure if a fault is suspected in the CAN data link. Also, use this procedure if the following diagnostic code is active:
Table 1
Diagnostic Trouble Codes for CAN Data Link
J1939 Code Code Description Comments
639-9 J1939 Network #1 : Abnormal Update Rate Another controller has incorrectly stopped transmitting data or another controller has incorrectly started transmitting data.
The ECM will log the diagnostic code.
The engine will not start.
Follow the troubleshooting procedure to identify the root cause of the fault. Note: Refer to Troubleshooting, "Sensors and Electrical Connectors"for the locations of the components listed in this procedure.The following background information is related to this procedure:The CAN data link is also known as the J1939 data links. A data link is an industry standard for sending data between different devices in the same application.High speed data is transferred via the data link. The data link cannot be accurately tested without complicated equipment. The data link requires a resistance of 60 Ohms between the two wires to transmit the data correctly. This resistance is made up of two 120 Ohm resistors. The two resistors are known as "Terminating Resistors". The terminating resistors should be at opposite ends of a data link circuit. If this resistance is not present, then the data will be intermittent or unreadable.Note: The wiring for a J1939 data link is a shielded twisted pair cable. If the wiring is damaged, the replacement type must be shielded twisted pair cable.
Illustration 1 g06108329
Schematic for the CAN data link
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the isolator switch to the OFF position.
B. Inspect the connectors in the circuit for the CAN data link.
Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the CAN data link.
D. Check the screw for the ECM connectors for correct torque of 6 N m (53 lb in).
E. Check all the wiring associated with the CAN data link for abrasions and pinch points.
Connector and/or wiring Result: The connector and/or wiring is NOT OK.
Repair: Repair the damaged wire or the damaged connector.
Use the electronic service tool to clear all logged diagnostic codes. Verify that the repair eliminates the fault.
Result: A damaged wire or damaged connector was not found.
Proceed to Test Step 2.
2. Check the Data Link Terminating Resistance
A. Disconnect the P1 connector from the ECM.
B. Measure the resistance between J1:46 and J1:47.
Between 50 Ohms and 70 Ohms
Result: The resistance is less than 50 Ohms - there is a short circuit in the harness.
Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all the seals are correctly in place and ensure that the connectors are correctly connected.
Use the electronic service tool to clear all logged diagnostic codes and then verify that the repair eliminates the fault.
Result: The resistance is between 110 and 130 Ohms - one of the terminating resistors may have failed.
Repair: Locate the