855480 Mercruiser OIL PIPE-RETURN

Illustration 1 g01261783
Schematic
Illustration 2 g01204484
P2 ECM connector
(P2-15) Intake manifold (boost) pressure sensor
(P2-17) Sensor common
(P2-28) Engine oil pressure sensor
(P2-40) Fuel pressure sensor
(P2-57) Atmospheric pressure sensor
(P2-72) +5 V Supply
Illustration 3 g01259757
P1 ECM connector
(P1-15) Right turbocharger inlet pressure
Illustration 4 g01142382
Locations of the pressure sensors (typical left side engine view)
(1) Intake manifold (boost) pressure sensor
(2) Fuel pressure sensor
(3) Atmospheric pressure sensor
(4) Engine oil pressure sensor
(5) J2/P2 ECM connectors
(6) J1/P1 ECM connectors
Illustration 5 g01142856
Typical air filter assembly
(7) Turbocharger inlet pressure sensor
Illustration 6 g01159881
Terminal locations at the sensor connector
(A) Sensor supply
(B) Sensor return
(C) Sensor signalTest Step 1. INSPECT ELECTRICAL CONNECTORS AND WIRING
Remove the electrical power from the ECM.
Thoroughly inspect the J1/P1 ECM connector and the J2/P2 ECM connector. Thoroughly inspect the connectors for each analog sensor.Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the sensor connectors that are associated with the active diagnostic code.
Check the ECM connector (allen head screw) for the proper torque. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Check the harness and wiring for abrasions and for pinch points from the sensors back to the ECM.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. CHECK FOR "ACTIVE" OR "LOGGED" DIAGNOSTIC CODES
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore the electrical power to the ECM.
Monitor the diagnostic codes on Cat ET. Check and record any diagnostic codes.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Determine if a diagnostic code has occurred several times.Note: A diagnostic code that is logged several times is an indication of an intermittent problem. Most intermittent problems are the result of a bad connection between a socket and a pin in a connector or a bad connection between a wire and a terminal. The problem may be caused by moisture, corrosion, or wear.
Determine if the problem is active and related to one of the following diagnostic codes:
03
04Expected Result:A diagnostic code is not active.Results:
OK - A diagnostic code is not active.Repair: The problem may be intermittent. If the problem is intermittent, refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - A diagnostic code is active. Proceed to Test Step 4.Test Step 3. CHECK THE 5 VOLT SUPPLY VOLTAGE AT THE SENSOR CONNECTOR
Do not disconnect the suspect connector.
Connect a voltmeter between pin A and pin B on the sensor side of the connector for the suspect sensor.
Measure the voltage between pin A and pin B for the suspect sensor(s).
Wiggle the harness while you monitor the voltage on the voltmeter. Perform the 45 N (10 lb) pull test on each wire in the circuit. Each terminal and each connector should easily withstand 45 N (10 lb) of tension and each wire should remain in the connector body. This test checks whether the wire was properly crimped in the terminal and wheth