75206 Mercruiser SCREW, TENSIONER ATTACHING (1 3/4") (L.H. ROTATION)

Use this procedure when the engine will not start and the electronic service tool indicates a faulty sensor by displaying "Not Detected" against the faulty sensor on the "No Start Parameter" screen.Complete the procedure in the order in which the steps are listed.
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position.
B. Inspect the connectors for the speed/timing sensors. Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Perform a 45 N (10 lb) pull test on each of the wires in the suspect sensor connector and the sensor connections at the ECM.
D. Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in).
E. Check the ground connection on the ECM for abrasions and pinch points.
F. Check the harness for abrasion and pinch points from the suspect sensor to the ECM.
G. Check that the suspect sensor is installed correctly. Check that the suspect sensor is fully seated into the engine.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all of the seals are properly in place and ensure that the connectors are correctly coupled.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points.
Proceed to Test Step 2.
2. Check For Active Diagnostic Codes
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position. If the engine will start, then run the engine.
D. Use the electronic service tool in order to monitor active diagnostic codes or recently logged diagnostic codes.
E. Turn the keyswitch to the OFF position.
Diagnostic codes
Result: Diagnostic code 3512-3 or 3512-4 is active or recently logged.
Proceed to Test Step 3.
3. Disconnect the Sensors One at a Time
A. Turn the keyswitch to the OFF position.
B. Disconnect the engine speed/timing sensors one at a time. Wait 30 seconds after each sensor is disconnected. Use the electronic service tool to monitor the diagnostic codes.
Note: The 3512-X or 3483-X diagnostic code will become inactive when the sensor that caused the 8 VDC diagnostic code is disconnected.
Diagnostic code
Result: The 3512-X or 3483-X diagnostic code is not active when all of the sensors are disconnected.
Repair: Replace the suspect sensor.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: The 3512-X or 3483-X diagnostic code is still active.
Proceed to Test Step 4.
4. Check the 8 VDC Supply from the ECM
A. Turn the keyswitch to the OFF position.
B. Disconnect the P2 connector from the ECM.
C. Turn the keyswitch to the ON position.
D. Measure the voltage from J2:18 on the ECM to a suitable ground.
7.5 VDC to 8.5 VDC
Result: The 8 VDC supply voltage from the ECM is within specification. The fault is in the harness.
Repair: Repair the faulty connectors or replace the harness. Reconnect all sensor and ECM connectors. Ensure that all of the seals are correctly in place. Ensure that all connectors are correctly coupled.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: The 8 VDC supply voltage from the ECM is outside the specified limits.
Contact the Dealer Solutions Network (DSN).