20088 Mercury NUT

Illustration 1 g00909631
Test Step 1. Check for Connector Damage.
Turn the keyswitch to the OFF position.
Turn the breaker for the engine ECM to the OFF position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test 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 for pinch points.Expected Result:The connectors and wiring should be free of following problems: damage, corrosion, abrasion and incorrect attachmentResults:
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 an Open in the Solenoid for the Engine Fan Control Valve.
Disconnect the solenoid connector J86/P86.
Measure the resistance between J86-1 and J86-2.Expected Result:The resistance should be between 3 and 7.8 Ohms.Results:
OK - The resistance is between 3 and 7.8 Ohms. Proceed to test step 3.
Not OK - The resistance is not between 3 and 7.8 Ohms. The solenoid is internally shorted or open.Repair: Replace the solenoid for the engine fan control valve. Stop.Test Step 3. Check for a Short in the Engine Fan Control Solenoid.
Measure the resistance between J86-1 and the engine ground.
Measure the resistance between J86-2 and the engine ground.Expected Result:The resistance should measure more than 20,000 Ohms.Results:
OK - The resistance measures more than 20,000 Ohms. Proceed to test step 4.
Not OK - The resistance measures less than 20,000 Ohms.Repair: Replace the solenoid for the engine fan control valve. Stop.Test Step 4. Check for a Short Circuit in the Harness.
Disconnect J2/P2.
Measure the resistance between P86-1 and P86-2.
Measure the resistance between P86-1 and the engine ground.
Measure the resistance between P86-2 and the engine ground.Expected Result:The resistance should measure more than 20,000 Ohms.Results:
OK - The resistance measures more than 20,000 Ohms. Proceed to test step 5.
Not OK - The resistance measures less than 20,000 Ohms. There is a short in the harness.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 5. Check the Resistance through the Harness.
Use a suitable piece of wire to short between P86-1 and P86-2.
Measure the resistance at the ECM connector between P2-19 and P2-7.
Remove the wire short. Reconnect the solenoid connector J86/P86.Expected Result:The resistance should measure less than 10 Ohms.Results:
OK - The resistance measures less than 10 Ohms. Proceed to 6.
Not OK - The resistance measures more than 10 Ohms. There is an open circuit in the harness or the connector.Repair: Repair the connectors or the wiring. Stop.Test Step 6. Check the Voltage from the ECM to the Engine Fan Control Solenoid.Note: This test will activate the diagnostic code 291-05. Delete the diagnostic code after completing this test step.
Remove wire F700-BU from ECM connector P2-19. Install a wire jumper into the socket for P2-19.
Remove wire E799-BR from ECM connector P2-7. Install a wire jumper into the socket for P2-7.
Reconnect ECM connector J2/P2.
Connect a voltmeter between the wire jumpers in P2-19 and P2-7.
Turn the breaker for the engine ECM to the ON position.
Turn the keyswitch to the START position.
Start the engine. Allow the engine to run until the engine has exited cold mode operation.
Measure the voltage between the wire jumpers in P2-19 and P2-7.
Turn the keyswitch to the OFF position.
Turn the breaker for the engine ECM to the OFF position.
Remove all wire jumpers. Replace all wires and reconnect all connectors.Expected Result:The voltage should be between 15 VDC and 27 VDC.Results:
OK - The voltage is between 15 VDC and 27 VDC. There is an intermittent problem in the harness.Repair: Perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors". Stop.
Not OK - The voltage is not between 15 VDC and 27 VDC.Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM". Stop.