811983 Mercruiser SCREW

Illustration 1 g00665917
Test Step 1. Check for Connector Damage.
Turn the circuit breaker for the engine to the OFF position.
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 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 the following problems: damage, corrosion, abrasion and incorrect attachment.Results:
OK - The connectors and wiring are okay. Proceed to test step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 2. Short the Wires at the Switch.
Disconnect the connector for the fuel pressure switch J106/P106.
Use a suitable piece of wire to short P106-1 and P106-2 together at the connector for the fuel pressure sensor.
Connect the Caterpillar Electronic Technician (ET) to the service tool connector J42.
Turn the circuit breaker for the engine to the ON position.
Turn the keyswitch to the ON position. The engine should be OFF.
Observe the status of the switch on the Cat ET.
Remove the wire short.
Observe the status of the switch on the Cat ET.
Turn the keyswitch to the OFF position.
Turn the circuit breaker for the engine to the OFF position.Expected Result:The status of the switch should be "NORMAL" when the short is installed. The status of the switch should be "HIGH" when the wire is removed.Results:
OK - The wiring and connectors between the fuel pressure switch and the ECM are okay.Repair: Replace the fuel filter. If the problem is not resolved, replace the switch. Verify that the switch solves the problem before you permanently install the switch. Stop.
Not OK - The status of the switch was not "NORMAL" when the short was installed. The status of the switch was not "HIGH" when the short was removed. Proceed to test step 3.Test Step 3. Check for Short Circuits in the Harness.
Disconnect the connector for the fuel pressure switch J106/P106.
Disconnect ECM connector J1/P1 and J2/P2.
Measure the resistance between pin P2-15 and pin P1-29.
Measure the resistance between pin P2-15 and the engine ground.Expected Result:The resistance should be greater than 20,000 Ohms.Results:
OK - The resistance is greater than 20,000 Ohms. Proceed to test step 4.
Not OK - The resistance is less than 20,000 Ohms. There is a short circuit in the wiring harness.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 4. Check the Resistance through the Harness.
Use a wire to short pin P106-1 to pin P106-2 at the connector for the fuel pressure switch.
Measure the resistance between pin P2-15 and pin P1-29 at the ECM connectors.Expected Result:The resistance should be less than 10 Ohms.Results:
OK - The resistance is less than 10 Ohms. Proceed to test step 5.
Not OK - The resistance is greater than 10 Ohms. There is excessive resistance in the wiring harness.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 5. Short the Switch at the ECM.
Disconnect ECM connector J1/P1 and J2/P2.
Remove the wires from pin P2-15 and from pin P1-29.
Insert a jumper wire with socket terminals on both ends at pin P2-15 and at pin P1-29.
Reconnect the connectors.
Turn the circuit breaker for the engine to the ON position.
Turn the keyswitch to the ON position. The engine should be OFF.Note: Additional diagnostic codes will be generated because the digital return will no longer be connected to other sensors and switches. Ignore the codes and clear the codes when you complete this test.
Observe the status of the switch on the Cat ET.
Turn the keyswitch to the OFF position.
Turn the circuit breaker for the engine to the OFF position.
Disconnect ECM connector J1/P1 and J2/P2.
Remove the wire short.
Reconnect all connectors.
Turn the keyswitch to the ON position. The engine should be OFF.
Observe the status of the switch on the Cat ET.
Turn the keyswitch to the OFF position.
Turn the circuit breaker for the engine to the OFF position.
Disconnect ECM connector J1/P1 and J2/P2.
Replace all wires. Reconnect all connectors.Expected Result:The status of the switch should be "NORMAL" when the short is installed. The status of the switch should be "HIGH" when the wire is removed.Results:
OK - The ECM is okay. The wiring and the connectors are okay. The problem may be intermittent.Repair: If the problem is intermittent, perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors". Stop.
Not OK - The ECM is not reading the switch input correctly.Repair: Replace the ECM. Refer to the diagnostic procedure Troubleshooting, "Replacing the ECM". Stop.