BOLT 6F7036 - Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with the Cat Data Link. Also, use this procedure if the diagnostic code in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table    
Code and Description    Conditions which Generate this Code    System Response    
247-9 SAE J1939 Data Link : Abnormal Update Rate     The Electronic Control Module (ECM) detects a loss of communication over the data link for two or more seconds.     The code is logged.    The Cat Data Link is used for the communication between the electronic modules. The Cat Data Link is used to communicate information from the ECM to the Electronic Monitoring System (EMS). The Cat Data Link is used for programming and troubleshooting the ECM.The ECM communicates with the EMS in order to share engine information and diagnostics that may affect engine operation.The ECM communicates with the Cat® Electronic Technician (Cat ET) in order to share status and diagnostic information. The Cat ET can also be used to configure the ECM parameters on the engine. This information will not be available if communications fail between the ECM and the Cat ET.
Illustration 1 g03360087
Typical schematic
Illustration 2 g03360115
Terminal locations at the P1-J1 connector (P1-8) Cat Data Link + (P1-9) Cat Data Link -
Illustration 3 g03360118
Terminal location of the service tool connector (Terminal D) Cat Data Link + (Terminal E) Cat Data Link -
Table 2
Troubleshooting Test Step    Value    Result    
1.Active Codes and Logged Codes
A. Establish communication between Cat Electronic Technician (ET) and the engine ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Determine if the 247-9 code is active or logged.
   
Codes    
Result: A Diagnostic code is present.
Repair: Troubleshoot any codes before proceeding with this procedure. Verify that the repair eliminated the problem.
Result: A diagnostic code is not present.
Proceed to Test Step 2.
   
2. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Thoroughly inspect the ECM connectors. Inspect all other connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect"
C. Perform a
45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
D. Check the ECM connector (allen head screw) for the proper torque of
6.0 N m (55 lb in).
E. Check the customer connector (allen head screw) for the proper torque of
2.25 0.25 N m (20 2 lb in).
F. Check the harness and the wiring for abrasion and for pinch points.    
Connectors    
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 3.
Result: The connectors and/or wiring are not OK.
Repair: Repair the wiring and/or connectors. Replace parts, if necessary. Ensure that all of the seals are properly in place and ensure that the connectors are coupled.
Verify that the repair eliminated the problem.
STOP
   
3. Check for Shorts in the Harness
A. Disconnect the P1 ECM connector.
B. Disconnect any module that is connected to the Cat Data Link.
C. Measure the continuity between the P1-9 and every terminal