78854 Mercury WAVE WASHER

Illustration 1 g01726176
Schematic of the diagnostic connector and the data link connector
Illustration 2 g01726177
View of the P1 pin locations for the diagnostic and data link connectors
(23) Data link +
(24) Data link - Test Step 1. Inspect Electrical Connectors and WiringRefer to the troubleshooting guide for the machine in order to check the machine wiring between the P1 connector on the engine ECM and the diagnostic connector.Expected Result:There are no faults in the machine wiring.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Perform the following repair:Repair the connectors and/or the harness. Refer to the troubleshooting guide for the machine.Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 2. Change the Electronic Service Tool Components
If another electronic engine is available, connect the electronic service tool to the other engine. Ensure that the same cables are used.
Turn the keyswitch to the ON position. Determine if the electronic service tool operates correctly on the other engine.
If another engine is not available, obtain a replacement communications adapter and a replacement set of cables. Ensure that the set of cables for the electronic service tool are a complete set.
Install the replacement communications adapter and the set of cables for the electronic service tool and connect to the diagnostic connector.
Turn the keyswitch to the ON position.
If changing the communications adapter or the cables allows the electronic service tool to operate correctly, use the following procedure:
Replace the components from the new set of cables with components from the old set of cables. Replace one component at a time.
Apply power to the electronic service tool after each of the components is replaced. Use this method to find the faulty component.
If changing the cables does not allow the electronic service tool to operate correctly, connect another electronic service tool.
Turn the keyswitch to the ON position. Expected Result:Result 1 The original electronic service tool works on another engine.Result 2 A different electronic service tool works on the original engine while the engine is being tested.Results:
Result 1 - Proceed to Test Step 3.
Result 2 - Repair: Send the faulty electronic service tool for repairs.STOPTest Step 3. Install a Test ECM
Make sure that the latest flash file for the application is installed in the ECM. Refer to Troubleshooting, "Flash Programming".
Contact the technical communicator at the Caterpillar dealer. Note: This consultation can greatly reduce the repair time.
If the technical communicator recommends the use of a test ECM, install a test ECM. Refer to Troubleshooting, "Replacing the ECM".
Remove all jumper wires and reconnect all connectors.
Connect the electronic service tool to the diagnostic connector.
Turn the keyswitch to the ON position.
Start the engine. Expected Result:The data link is operating correctly.Results:
OK - Repair:
If the fault is resolved with the test ECM, reconnect the suspect ECM.
If the fault returns with the suspect ECM, replace the suspect ECM.
Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault. STOP
Not OK - Repair: Repeat this diagnostic procedure from the beginning.STOP