SEAL-O-RING 4J0520 - Caterpillar

Use this procedure if the electronic service tool will not communicate with the ECM through the data link.The following background information is related to this procedure:The data link is the standard data link that is used by the ECM in order to communicate with the electronic service tool.The ECM provides multiple connections for the data link. The technician must ensure that the correct connector is being tested. The connection that is used is dependent on the application.The positive data link signal is from P1:8 to pin "D" of the diagnostic connector. The negative data link signal is from P1:9 to pin "E" of the diagnostic connector.The following information refers to the pin number. Ensure that the correct connector is used.CommunicationThe electronic service tool may indicate the following error message:The version of the ECM is not recognized and the integrity of the changed parameters and displayed data is not guaranteed.This message will indicate that the version of the software that is in the electronic service tool is obsolete. Install the latest version of the software for the electronic service tool in order to rectify the fault.
Illustration 1 g03589624
Schematic of the diagnostic connector and the data link connector
Illustration 2 g02028056
P1 pin locations for the diagnostic connector (8) Data link + (9) Data link -
Illustration 3 g01241517
Typical view of the diagnostic connector from the wire side (A) Switched battery + (B) Battery ground (GND) (D) Data link + (E) Data link -
Table 1
Troubleshooting Test Steps    Values    Results    
1. Inspect Electrical Connectors and Wiring
A. Turn the isolator switch to the OFF position.
B. Thoroughly inspect the following electrical connectors:
P1/J1 ECM connector
Diagnostic connector
Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a
45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the data link.
D. Check the screw for the ECM connectors for correct torque of
6N m (53 lb in).
E. Check the harness for abrasion and pinch points from the wires that connect the diagnostic connector to the ECM.
    Damaged wire or connector     Result: A damaged wire or damaged connector was found.
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. Determine the Type of Fault in the Data Link
A. Connect the electronic service tool to the diagnostic connector that is on the engine harness or on the application.
B. Turn the isolator switch to the ON position.
   
Power lamp on    
Result: The power lamp is not illuminated on the communications adapter - the communications adapter is not receiving the correct voltage.
Proceed to Test Step 3.
Result: The power lamp is illuminated on the communications adapter - the communications adapter is receiving the correct voltage.
Proceed to Test Step 5.
   
3. Check the Battery Voltage at the Diagnostic Connector
A. Disconnect the electronic service tool from the diagnostic connector.
B. Turn the isolator switch to the ON position.
C. Use