825078 Mercury BUSHING

Illustration 1 g02225673
Schematic of the circuit for the PWM sensorsTest Step 1. Inspect the Electrical Connectors and the Wiring
Set the engine control to the OFF/RESET position.Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Illustration 2 g01391862
Locations of the ECM connectors (1) J2/P2 ECM connectors (2) J1/P1 ECM connectors
Illustration 3 g01391863
Locations of components for the PWM sensors (3) Engine coolant pressure sensor (outlet) (4) Air inlet pressure sensor
Thoroughly inspect ECM connectors (1) and (2). Also, thoroughly inspect the connectors for sensors (3) and (4) .
Check the allen head screw for each of the ECM connectors for the proper torque.
Illustration 4 g01391854
Terminal locations at the P1 ECM connector for the PWM sensors (P1-4) +8 VDC (P1-5) Return (P1-10) Engine coolant pressure (outlet)
Illustration 5 g01391857
Terminal locations at the P2 ECM connector for the PWM sensors (P2-65) +8 VDC (P2-66) Return (P2-68) Air inlet pressure
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the PWM sensors.
Check the harness and wiring for abrasion and for pinch points from each PWM sensor to the ECM.Expected Result:All of the connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Check for Active Diagnostic Codes that are Related to the 8 VDC Power Supply
Establish communication between Caterpillar Electronic Technician (ET) and the ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
Observe the "Active Diagnostic" screen on Cat ET. Allow a minimum of 30 seconds for any codes to activate. Look for these codes:
41-3 8 Volt DC Supply voltage above normal
41-4 8 Volt DC Supply voltage below normalExpected Result:There are no active codes for the 8 V supply.Results:
OK - There are no active codes for the 8 V supply. Proceed to Test Step 3.
Not OK - There is an active code for the 8 V supply.Repair: There is a problem with the 8 V power supply. Refer to Troubleshooting, "+8 V Sensor Voltage Supply" for information that is related to troubleshooting the power supply for these sensors.STOPTest Step 3. Check for Active Diagnostic Codes that are Related to the PWM Sensors
Determine if any of these diagnostic codes are active:
106-3 Air Inlet Pressure Sensor voltage above normal
106-4 Air Inlet Pressure Sensor voltage below normal
106-8 Air Inlet Pressure Sensor abnormal frequency, pulse width, or period
109-03 Engine Coolant Outlet Pressure Sensor voltage above normal
109-08 Engine Coolant Outlet Pressure Sensor abnormal frequency, pulse width, or periodExpected Result:None of the above codes are active.Results:
OK - None of the above codes are active.Repair: There may be an intermittent electrical problem in the harness or in a connector.If any of the above codes are logged and the engine is not running properly, refer to Troubleshooting, "Troubleshooting Without a Diagnostic Code".If the engine is running properly at this time, there may be an intermittent problem in the harness causing the codes to be logged. Refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - At least one of the above diagnostic codes is active. Proceed to Test Step 4.Test Step 4. Verify the Supply Voltage to the Sensor
Disconnect the suspect sensor.
Illustration 6 g00896288
Harness connector for the PWM sensors (A) 8 V supply or 5 V supply (B) Return
At the harness connector for the suspect sensor, measure the voltage between terminals A and B.Expected Result:The voltage between terminals A and B is between 7.6 VDC and 8.4 VDC.Results:
OK - The voltage is within the specification. The correct voltage is present at the sensor connector. Proceed to Test Step 5.
Not OK - The voltage is not within the specification. The correct voltage is not present at the sensor connector.Repair: There is a problem in the harness between the ECM and the sensor connector. Verify that the wiring and/or connectors are OK. Repair any faulty wiring and/or connectors, when possible. Replace any faulty wiring and/or connectors, if necessary. Refer to Troubleshooting, "Inspecting Electrical Connectors".STOPTest Step 5. Check the Signal Wire for Battery Voltage