899912031 Mercury TAPPET, (3.621)

Illustration 1 g01234143
Test Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
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Left side engine view (1) J1/P1 ECM connector
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Engine control panelRear view of scraper (2) Engine shutdown switch
Thoroughly inspect connectors (1). Thoroughly inspect the connectors for switch (2). Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
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P1 terminals that are associated with the engine shutdown switch (P1-5) Digital return (P1-41) Engine shutdown switch (NO) (P1-59) Engine shutdown switch (NC)
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.
Check the torque of the allen head screws for the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points.Expected Result:All of the connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not OK.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.STOPTest Step 2. Check the Switch Status on Cat ET
Connect Cat ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Turn the keyswitch to the ON position.
Observe the status for "Shutdown Switch" on Cat ET while you operate the engine shutdown switch.
Turn the keyswitch to the OFF position.Expected Result:The status is "On" with the switch in the STOP position. The status is "Off" with the switch in the RUN position.Results:
OK - The switch is operating normally.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.STOP
Not OK - The status of the switch is incorrect. Proceed to Test Step 3.Test Step 3. Short the Wires at the Switch
Remove the fasteners that attach the engine control panel to the scraper.
Disconnect the harness connectors for the engine shutdown switch.
Install a jumper wire between terminals B (Engine shutdown switch (NC) and C (Digital sensor return) on the harness connector for the switch.
Turn the keyswitch to the ON position and observe the status for "Shutdown Switch" on Cat ET.The status should be "Off".
Turn the keyswitch to the OFF position.
Remove the jumper wire.
Install the jumper wire between terminals A (Engine shutdown switch (NO) and C (Digital sensor return) on the harness connector for the switch.
Ensure that the keyswitch is in the ON position and observe the status for "Shutdown Switch" on Cat ET.The status should be "On".
Turn the keyswitch to the OFF position.
Remove the jumper wire.Expected Result:The status is "Off" with the jumper wire between terminals B and C. The status changes to "On" when you move the jumper wire to terminals A and C.Results:
OK - The wiring from the harness connector to the ECM is OK. There is a problem with the switch.Repair: Temporarily connect a new switch. Verify that the new switch solves the problem before you permanently install the new switch.STOP
Not OK - The ECM did not detect the shorts. There is a problem in the harness and/or the ECM. Proceed to Test Step 4.Test Step 4. Short the Switch Inputs at the P1 Connector
Turn the keyswitch to the OFF position.
Install a 208-0059 Adapter Cable As (70-PIN BREAKOUT) at the J1/P1 connector.
Install a jumper wire between terminals 59 (Engine shutdown switch (NC) and 5 (Digital sensor return) at the breakout.
Turn the keyswitch to the ON position and observe the status for "Shutdown Switch" on Cat ET.The status should be "Off".
Turn the keyswitch to the OFF position.
Remove the jumper wire from the breakout.
Install the jumper wire between terminals 41 (Engine shutdown switch (NO) and 5 (Digital sensor return) at the breakout.
Turn the keyswitch to the ON position and observe the status for "Shutdown Switch" on Cat ET.The status should be "On".
Turn the keyswitch to the OFF position.Expected Result:The status is "Off" with the jumper wire between terminals 59 and 5. The status changes to "On" when you move the jumper wire to terminals 41 and 5.Results:
OK - The ECM properly reads the switch inputs at the P1 connector but not at the harness connector for the switch.Repair: The wiring harness is faulty. Repair the wiring harness. Verify that the repair eliminates the problem.STOP
Not OK - The ECM is not reading the switch inputs properly.Repair: Verify your results.Replace the ECM. Refer to Troubleshooting, "Replacing the ECM" before replacing the ECM.STOP