0388673 JOHNSON PISTON,.030,115 HP

Illustration 1 g00830986
Schematic for power train data link
Illustration 2 g00768550
ECM pin locations
Illustration 3 g00721539
Terminal locations for ECMTest Step 1. Inspect Electrical Connectors and Wiring
Thoroughly inspect ECM vehicle harness connector J1/P1, the firewall bulkhead connector, the connectors for the power train control module, and the connector terminals for the SAE J1939 data link. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the SAE J1939 Data Link.Refer to Illustration 3.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and wiring for abrasion and pinch points from the data link connectors back to the ECM.Expected Result:All connectors, pins and sockets should be completely coupled and/or inserted and the harness and wiring should be free of corrosion, abrasion or pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Perform the following repair:Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem. Stop.Test Step 2. Connect Cat ET and Check for Active Diagnostic Codes
Connect Cat ET to the data link connector.
Turn the key switch to the ON position.
Monitor the active diagnostic code screen of Cat ET. Check and record active diagnostic codes.Expected Result:One of the following diagnostic codes is active:
231-02 J1939 Data Incorrect (58)
231-12 J1939 Device Not Responding (58)Results:
Yes one of the codes is active - Proceed to Test Step 3.
No - Proceed to Test Step 4.Test Step 3. Use the Special Test on Cat ET to Check the Devices on the J1939 Data Link
Connect Cat ET to the data link connector.
Access the special test "J1939 Receive Communication Status". The special tests are located under the Diagnostic menu.
Cat ET will display the J1939 sources that have transmitted at least one good message that has been successfully received by the ECM. If the ECM has not received any messages from a source, that source will not be displayed. Examples of devices that can use the J1939 data link include the following switches:
Switches that are programmed to "Instrument Cluster"
Switches that are programmed to "Body Controller"
Switches that are programmed to "Cab Controller"
Cat ET will display the J1939 source in the "Description" column. The "Status" column displays the status of the device.
If a message is not received from a device, Cat ET will display "Not Receiving".
The status screen on Cat ET can be set to display the status of a device that is not working. The status screen will display "No Comm" if a message is not received from the device.Expected Result:Cat ET displays the devices that are used on the vehicle and the ECM is receiving messages from the devices.Results:
Yes - The ECM is receiving messages from the devices that are installed on the vehicle. Stop.
No - The ECM is not receiving messages from the devices that are installed on the vehicle.Repair: The devices that can be programmed to use the J1939 data link can be circuits with two wires or circuits with three wires. Bad connections are the most frequent problem. Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that the connectors are free of corrosion. Stop.Test Step 4. Check the Power Train Status Screen on Cat ET