826713 23 Mercruiser NUT, (.750-16), UPPER SWIVEL SHAFT

Probable Causes
Active codes and logged codes
Electrical connections
Unstable fuel supply
Switches
Circuit protection
Engine speed/timingRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps Values Results
1. Active Codes and Logged Codes
A. Certain diagnostic codes and/or event codes may cause an engine shutdown. Connect the electronic service tool and check for active codes and for logged codes.
B. Use the electronic service tool to check for associated diagnostic trouble codes.
Codes
Result: There are associated diagnostic trouble codes active or logged.
Repair: Troubleshoot any active or logged associated diagnostic trouble codes before continuing with this procedure.
Result: There are no associated diagnostic trouble codes active or logged.
Proceed to Test Step 2.
2. Electrical Connections
A. Check for the correct installation of the ECM J1/P1 and the J2/P2 connectors. Check for correct installation of the fuel injector connectors.
Connectors
Result: There are suspect connectors.
Repair: Perform the "Wiggle Test" on the electronic service tool.
Repair or replace connectors that are suspect.
Result: There are no suspect connectors.
Proceed to Test Step 3.
3. Electrical Connections
A. Check the power and ground connections to the ECM. Refer to Troubleshooting, "Electrical Power Supply - Test".
Electrical Connectors
Result: The electrical connections are OK.
Proceed to Test Step 4.
Result: The electrical connections are not OK.
Repair: Repair or replace the damaged connectors. Verify that the repair eliminated the fault.
4. Unstable Fuel Supply
A. Inspect the fuel system. Refer to Systems Operation, Testing and Adjusting, "Fuel System - Inspect" for additional information.
Cold weather adversely affects the characteristics of the fuel. Refer to the engine Operation and Maintenance Manual, "Cold Weather Operation" for further information.
B. Check fuel quality. Check the fuel tank for debris or foreign objects which may block the fuel supply.
C. Check for air in the fuel system. Refer to Systems Operation, Testing and Adjusting, Air in Fuel - Test.
Fuel
Result: The fuel quality is OK.
Proceed to Test Step 5.
Result: The fuel quality is not OK.
Repair: Replace the fuel. Verify that the repair eliminated the fault.
5. Switches
A. Check the keyswitch input to the ECM.
B. Check any engine shutdown switches and associated wiring.
Switches
Result: The shutdown switches and wiring are OK.
Proceed to Test Step 6.
Result: The shutdown switches and wiring are not OK.
Repair: Make the necessary repairs, Verify that the repair eliminated the fault.
6. Circuit Protection
A. Inspect the wires and connectors to all circuit protection for the engine.
B. Check the device for circuit protection.
Circuit protection
Result The circuit protection device is tripped.
Repair: Reset the circuit breakers if the circuit breakers are tripped. If necessary, replace blown fuses. Prior to returning the engine to service, determine the condition that caused the circuit breaker to trip or the fuse to blow. Make the necessary repairs.
Result The circuit protection device is OK.
Proceed to Test Step 7.
7. Engine Speed/Timing Sensors
A. Inspect the connectors for the engine speed/timing sensors.
B. Crank the engine. If the engine starts and no speed timing codes are logged, the speed timing circuit is operating correctly.
Speed/Timing
Result: The Speed/Timing sensor circuit is not operating correctly.
Repair: Test the speed/timing circuit. Refer to Troubleshooting, "Speed/Timing `- Test". Verify that the repair eliminated the fault.
If the fault is still present, contact the Dealer Solutions Network (DSN).