67450 Mercruiser SCREW, COVER TO CYLINDER BLOCK (2 1/4")

Illustration 1 g00813133
Typical schematicTest Step 1. Check for Connector Damage.
Turn the keyswitch to the OFF position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other 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 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 the wiring for abrasion and pinch points.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 - The connectors and wiring are okay. Proceed to test step 2.
Not OK - The connectors and/or wiring are not okay.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 2. Check for a Short Circuit in the Wiring Harness.
Disconnect ECM connector J1/P1 and all of the digital sensors.
Measure the resistance between the digital supply P1-35 (700-OR) and the digital return P1-29 (998-BR) on connector P1.
Measure the resistance between the digital supply P1-35 (700-OR) and engine ground.
Measure the resistance between the digital return P1-29 (998-BR) and engine ground.Expected Result:The resistance should be greater than 20,000 Ohms for each measurement.Results:
OK - The resistance is greater than 20,000 Ohms. Proceed to test step 3.
Not OK - The resistance is less than 20,000 Ohms.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 3. Check the Digital Supply Voltage at the ECM.
Install a Breakout T at ECM connector J1/P1.
Remove the wire P1-35 from the harness side of the Breakout T.
Remove the wire P1-29 from the harness side of the Breakout T.Note: If you remove the sensor common from the ECM an open circuit diagnostic code will be generated for all sensors that use the sensor common. Troubleshoot the original code. Delete the logged diagnostic codes when you are finished.
Turn the keyswitch to the ON position. The engine should be off.
Measure the voltage between the digital sensor supply P1-35 and the digital sensor return P1-29 at the Breakout T.
Turn the keyswitch to the OFF position.
Remove the Breakout T and reconnect ECM connector J1/P1.Expected Result:The supply voltage should be 8.0 0.4 VDC.Results:
OK - The supply voltage is 8.0 0.4 VDC. The digital sensor supply is producing the correct voltage. Proceed to test step 4.
Not OK - The supply voltage is not 8.0 0.4 VDC. The digital sensor is not producing the correct voltage.Repair: Perform the following diagnostic procedure Troubleshooting, "Electrical Power Supply". Stop.Test Step 4. Check the Digital Sensor Supply Voltage at the Sensor Connector.
Turn the keyswitch to the ON position. The engine should be off.
Measure the digital sensor supply voltage between the digital supply terminal-A (700-OR) and the digital return terminal-B (998-BR) of all the digital sensors.Note: If the sensor is disconnected from the harness, an open circuit diagnostic code will be generated for that sensor. Troubleshoot the original code. Delete the logged diagnostic codes when you are finished.
Turn the keyswitch to the OFF position.Expected Result:The supply voltage should be 8.0 0.4 VDC.Results:
OK - The supply voltage is 8.0 0.4 VDC at all of the digital sensor connectors. Proceed to test step 5.
Not OK - The supply voltage is not 8.0 0.4 VDC. There is an open circuit in the harness or connectors.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 5. Check the Digital Sensors for Short Circuits.
Install a Breakout T at ECM connector J1/P1.
Turn the keyswitch to the ON position. The engine should be off.Note: If the sensor is disconnected from the harness, an open circuit diagnostic code will be generated for that sensor. Troubleshoot the original code. Delete the logged diagnostic codes when you are finished.
Connect one digital sensor at a time.
Measure the voltage between the digital sensor supply P1-35 and the digital sensor return P1-29 at the Breakout T. Repeat these steps with all of the digital sensors.
Turn the keyswitch to the OFF position.
Remove the Breakout T and reconnect ECM connector J1/P1.Expected Result:The supply voltage should be 8.0 0.4 VDC.Results:
OK - The supply voltage is 8.0 0.4 VDC. The digital sensor supply is correct. The harness and sensors are okay. Repair: The problem may be intermittent. Check the wiring and connectors for problems. Perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors". Stop.
Not OK - The supply voltage is not 8.0 0.4 VDC. The sensor may be internally shorted.Repair: Temporarily install a new sensor. Ensure that the problem is no longer present. Reinstall the old sensor. If the problem returns, replace the sensor. Stop.