881744 Mercruiser COVER

Illustration 1 g03056696
Test Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF position.
Thoroughly inspect the ECM connector J1/P1. Inspect all of the sensor connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details on inspecting connectors.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2
Not OK - There is a problem in the connectors and/or wiring.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 for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.Note: Wait at least 15 seconds in order for the diagnostic codes to become active.Expected Result:None of the following diagnostic codes are active:
771-05
771-06Results:
OK - No diagnostic codes are active.Repair: The problem may have been related to a faulty connection in the harness. Carefully reinspect the connectors and wiring. Refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - A 771-05 diagnostic code is active. Proceed to Test Step 3.
Not OK - A 771-06 diagnostic code is active. Proceed to Test Step 4.Test Step 3. Check for an Open in the Shutter Solenoid Circuit
Disconnect harness HH-C10 from the solenoid.
Connect a jumper wire between the terminals of the harness connector for the shutter control solenoid on connector HH-C10. Connect the jumper wire on the harness side of the connector.
Clear the 771-05 code.
Activate the Shutter override. Results:
A 771-05 code became active during the override. The ECM did not detect the jumper wire. There is an open circuit in the wiring between the solenoid and the ECM connector. There may be a problem with a connector. - Proceed to Test Step 5
A 771-06 code became active during the override. The ECM detected the jumper wire. There is a problem with the solenoid. - Repair: Replace the solenoid.Verify that the problem is resolved.STOPTest Step 4. Check for a Short in the Shutter Solenoid Circuit
Disconnect the harness for the Shutter Solenoid.
Clear the 771-06 code.
Activate the Shutter override.Results:
A 771-06 code became active during the override. The ECM did not detect the open circuit. - There is a short circuit in the wiring between the solenoid and the ECM connector. Proceed to Test Step 6
A 771-05 code became active during the override. - The ECM detected the open circuit. The wiring is OK. The relay has a short circuit.Repair: Replace the relay.Verify that the problem is relay.STOPTest Step 5. Check for an Open in the Shutter Control Relay Circuit
Disconnect the harness from the relay.
Connect a jumper wire between the terminals of the harness connector for the shutter control relay. The relay is replaced with a short circuit.
Clear the 771-05 code.
Activate the Shutter override.Results:
A 771-05 code became active during the override. - The ECM did not detect the jumper wire. There is a problem between the shutter relay and the ECM.Repair: Repair the harness or replace the harness.Verify that the problem is resolved.STOP
A 771-06 code became active during the override. - The ECM did detect the jumper wire.Repair: Replace the relay.Verify that the problem is resolved.STOPTest Step 6. Check for a Short in the Shutter Control Relay Circuit
Disconnect the harness for the Shutter Control Relay.
Clear the 771-06 code.
Activate the shutter override.Results:
A 771-06 code became active during the override. - The ECM did not detect the open circuit. There is a problem between the shutter relay and the ECM.Repair: Repair the harness or replace the harness.Verify that the problem is solved.STOP
A 771-05 code became active during the override. - The ECM did detect the open circuit. There is a problem with the relay.Repair: Replace the relay.Verify that the problem is resolved.STOP