850418 Mercruiser STUD (115MM)

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 in the ATA data link.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 4. Change the Components for Using Cat ET
Use the same Cat ET components and attempt to connect to another Caterpillar electronic engine.
If another engine is not available, find a different communication adapter and find a different set of Cat ET cables. Ensure that the communication adapter and cables are a complete set. Connect Cat ET to the service tool connector with the new communication adapter and cables.
Turn the ignition switch to the ON position. Determine if Cat ET communicates correctly with the engine ECM.
If changing the communication adapter and cables causes Cat ET to properly communicate, use the following procedure:
Replace the new communication adapter and cables with the old communication adapter and cables by changing one component at a time.
Repower Cat ET after each component is changed. Use this method until you find the faulty component. Results:
Result 1 - The original communication adapter and cables work on another engine. Repair: Cat ET is working properly.Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Result 2 - A different communications adapter and cables work on the original engine. Repair: The original Cat ET components are not working properly.Repair the Cat ET component that is faulty. If a repair is not practical, replace the faulty Cat ET component.STOP