881679 Mercruiser VALVE, Exhaust

Illustration 1 g00770407
Illustration 2 g00770414
Test Step 1. Check The Electrical Connectors and The Wiring
Thoroughly inspect the ECM vehicle harness connector J1/P1, terminal 40, and the firewall bulkhead connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the fast idle switch circuit.The wires are on the following terminals:
terminal 40
terminal 5
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and the wiring for abrasion and pinch points from the battery to the ECM. Then, check from the ignition key switch to the ECM.Refer to Illustration 2 for terminal locations for the ECM.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring should be free of corrosion, abrasion or pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair the wiring and connectors or replace the wiring or the connectors. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.STOPTest Step 2. Check the Status of the Fast Idle Switch On The Electronic Service Tool.
Connect an Electronic Service Tool at the cab data link connector.
Turn the ignition key switch to the ON position.
Operate the switch in the ON position and the OFF position.
View the "Fast Idle Switch" status on the Electronic Service Tool.Note: A fast idle rpm must be programmed in order to automatically go to a set speed.Expected Result:The status screen should indicate "ON" if the switch is turned on. The status screen should indicate "OFF" if the switch is off.Results:
YES - The switch is operating normally. Continue troubleshooting if the original condition is not resolved.STOP
NO - The ECM is not reading the "Switch Status" change. Proceed to Test Step 3.Test Step 3. Check The Switch Circuit for the ECM.
Illustration 3 g00770457
Turn the ignition key switch to the OFF position.
Install a 70 terminal breakout T to the ECM vehicle harness connector J1/P1.
Fabricate a jumper wire 100 mm (4 inch) long. Crimp a Deutsch pin to both ends of the wire.
Insert the jumper wire into terminal 40 of the breakout T. Connect the other end of the jumper wire to terminal 5 in the breakout T. Terminal 5 is AP sensor/switch common.
Connect an Electronic Service Tool at the cab data link connector.
Turn the ignition key switch to the ON position.
Alternately remove the jumper wire and then insert the jumper wire from terminal 5. At the same time, monitor the "Status Screen" on the Electronic Service Tool.Expected Result:The "Switch Status" changes to "ON" with the jumper wire in place. The "Switch Status" changes to "OFF" when the jumper wire is removed.Results:
Yes - The ECM is functioning properly at this time. Proceed to Test Step 4.
No - The ECM is not functioning properly.Repair: Perform the following repair:
Temporarily connect a test ECM.
Remove all jumpers and replace all connectors.
Recheck the system for Active diagnostic codes.
Repeat the test step.
If the problem is resolved with the test ECM, reconnect the suspect ECM.
If the problem returns with the suspect ECM, replace the ECM.
Verify that the repair eliminates the problem.STOPTest Step 4. Insert a Jumper Wire at the Switch.
Turn the ignition key switch to the OFF position.
Reconnect the ECM vehicle harness connector J1/P1.
Fabricate a jumper wire 100 mm (4 inch) long. Crimp a Deutsch pin to both ends of the wire.
Insert the jumper wire between the two switch terminals of the fast idle switch.
Turn the ignition key switch to the ON position.
Alternately remove the jumper wire and then insert the jumper wire at the switch terminals. At the same time, watch the "Status Screen" on the Electronic Service Tool.Expected Result:The "Switch Status" changes to "ON" with the jumper wire in place. The "Switch Status" changes to "OFF" when the jumper wire is removed.Results:
YES - Repair: Perform the following diagnostic procedure:Replace the fast idle switch.Verify that the repair eliminates the problem.STOP
NO - There is a problem in the wire harness between the fast idle switch and the ECM. Proceed to Test Step 5.Test Step 5. Insert A Jumper Wire At The Bulkhead Connector.
Turn the ignition key switch to the OFF position.
Fabricate a jumper wire 100 mm (4 inch) long. Crimp a Deutsch pin to both ends of the wire.
Locate the socket for the fast idle switch in the engine side of the bulkhead connector for the wiring to the ECM.
Insert the wire jumper pin between the switch socket and the sensor common connection. Install the jumper wire on the engine side of the bulkhead connector for the wiring to the ECM.
Turn the ignition key switch to the ON position.
Alternately connect and then disconnect the jumper wire. At the same time, monitor the "Status Screen" on the Electronic Service Tool.Expected Result:The "Switch Status" changes from "ON" with the jumper wire in place. The "Switch Status" changes to "OFF" when the jumper wire is removed.Results:
YES - The problem is in the vehicle wiring between the bulkhead connector and the switch. Insp