PLATE 3023932 - Caterpillar

The ATA data link is a two wire electrical connection that is used to flash program the Electronic Control Module (ECM). The ATA data link is connected to the ECM at the following two J1 terminals:
J1:7 (ATA data link (+))
J1:1 (ATA data link (-))"WinFlash" is used to communicate through the ATA data link only for the purpose of flash programming. Select "WinFlash" from the "Utilities" menu in Caterpillar Electronic Technician (ET) in order to begin the process of flash programming. Refer to Troubleshooting, "Flash Programming" for more information.
Illustration 1 g00812448
Schematic
Test Step 1. Test Communication of the Cat Data Link
Turn the keyswitch to the OFF/RESET position.
Connect Cat ET to the service tool connector.
Turn the keyswitch to the ON position.
Select the engine ECM from the "ECM Selector" screen on Cat ET. Expected Result:The Cat Data Link is functioning properly.Results:
OK - The Cat Data Link is functioning properly. Proceed to Test Step 2.
Not OK - The Cat Data Link is not functioning properly.Repair: Proceed to Troubleshooting, "Electronic Service Tool Will Not Communicate with ECM".STOPTest Step 2. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect J1/P1 ECM connector and all other connectors in the wiring harness. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. Note: Refer to the electrical system schematic for further information about the machine wiring.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the sensor connectors that are associated with the active diagnostic code.
Check the ECM connector (allen head screw) for the proper torque. Expected Result:All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasion, and of pinch points. Proceed to Test Step 3.
Not OK - There is a problem with the harness.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 3. Check the Resistance of the ATA Data Link
Illustration 2 g00812603
J1/P1 Breakout
Illustration 3 g00755883
Service Tool Connector
Verify that the keyswitch is in the OFF/RESET position.
Disconnect the J1/P1 ECM connector.
Measure the resistance between P1:1 (ATA data link (-)) and P1:7 (ATA data link (+)). Note: Resistance should be greater than 20,000 Ohms.
Install a jumper wire with Deutsch sockets on each end between J42:J and J42:H.
Measure the resistance between P1:1 (ATA data link (-)) and P1:7 (ATA data link (+)). Note: Resistance should be less than ten Ohms.
Remove the jumper wire and reconnect the J1/P1 ECM connector. Expected Result:Resistance is less than ten Ohms when the jumper wire is installed. The resistance is greater than 20,000 Ohms, when the jumper wire is removed.Results:
OK - The resistance is acceptable. There does not appear to be a problem with the ATA data link at this time.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.STOP
Not OK - The resistance is not acceptable. There is either an open circuit or a short circuit