879194142 Mercruiser PIPE

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SchematicTest Step 1. Test Communication of the CAT Data Link
Turn the keyswitch to the OFF/RESET position.
Connect the electronic service tool to the service tool connector.
Turn the keyswitch to the ON position.
Select the engine ECM from the "ECM Selector" screen on the electronic service tool.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". Stop.Test Step 2. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect the 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.Expected Result:All connectors, pins, and sockets should be completely inserted and coupled. The harness and wiring should be free of corrosion, abrasion, and pinch points.Results:
OK - Proceed to Test Step 3.
Not OK - Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 3. Check the Resistance of the ATA Data Link
Illustration 2 g00938667
J1/P1 Breakout
Illustration 3 g00755883
Service Tool Connector
Turn the keyswitch to the OFF 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 10 ohms.
Remove the jumper wire and reconnect the J1/P1 ECM connector.Expected Result:Resistance should be less than 10 ohms when the jumper wire is installed. The resistance should be greater than 20,000 ohms, when the jumper wire is removed.Results:
OK - 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 - 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. Stop.Test Step 4. Change the Electronic Service Tool Components
Use the same electronic service tool 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 electronic service tool cables. Ensure that the communication adapter and cables are a complete set. Connect the electronic service tool to the service tool connector with the new communication adapter and cables.
Turn the ignition key switch to the ON position. Determine if the electronic service tool communicates correctly with the engine.
If changing the communication adapter and cables causes the electronic service tool 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 the electronic service tool 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: The electronic service tool is working properly.Refer toTroubleshooting, "Electrical Connectors - Inspect". Stop.
Result 2 - A different communications adapter and cables work on the original engine. Repair: The original electronic service tool components are not working properly.Repair the electronic service tool component that is faulty. If a repair is not practical, replace the faulty electronic service tool component. Stop.