40074 20 Mercury SCREW, (M6 x 20)

Illustration 1 g01136421
Schematic for auxiliary temperature sensor
The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.
Test Step 1. Verify that the Auxiliary Temperature Sensor is Installed
Locate the auxiliary temperature sensor. Verify that a auxiliary temperature sensor is installed.
Connect Cat ET to the service tool connector. Check the "Auxiliary Temperature Sensor" parameter on the configuration screen.Expected Result:An auxiliary temperature sensor is installed on the application and the "Auxiliary Temperature Sensor" parameter is programmed to a value of "1" to "120" in Cat ET.Results:
OK - The auxiliary temperature sensor is properly installed. Proceed to Test Step 2.
Not OK - The auxiliary temperature sensor is not installed on the application.Repair: Change the "Auxiliary Temperature Sensor" parameter to "0", or install the sensor. Verify that the repair eliminates the problem.STOP
Not OK - The "Auxiliary Temperature Sensor" parameter is improperly programmed.Repair: Use Cat ET to program the "Auxiliary Temperature Sensor" parameter to a value of "1" to "120". Verify that the repair eliminates the problem.STOPTest Step 2. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01136484
Top view (1) P1 ECM connector (2) P2 ECM connnector (3) P3 Customer connetor
Thoroughly inspect connectors (1), (2), and (3). Also inspect the connector for the auxiliary temperature sensor. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01136422
ECM P1 connector (P1-35) +8 V Supply (P1-29) Return
Illustration 4 g01136469
ECM P2 connector (P2-25) Auxiliary temperature sensor
Illustration 5 g01136423
J3 and P3 connectors (8) +8 V supply (9) Return (11) Auxiliary temperature sensor
Perform a 45 N (10 lb) pull test on each of the wires that is associated with the auxiliary temperature sensor circuit.
Check the torque of the allen head screws for the ECM connectors and for the customer connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The connectors and wiring are in good repair. Proceed to Test Step 3.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the wiring and connectors or replace the wiring and the connectors. Ensure that the seals are correctly installed on each of the connectors. Verify that the repair eliminates the problem.STOPTest Step 3. Check the Sensor Supply Voltage at the Sensor Connector
Disconnect the J114/P114 auxiliary temperature sensor connector.
Turn the keyswitch to the ON position.
Use a multimeter to measure the voltage between terminal A (+8 V digital supply) and terminal B (sensor return) at the harness connector for the auxiliary temperature sensor.
Turn the keyswitch to the OFF position. Connect the J114/P114 auxiliary temperature sensor connector.
Expected Result:The digital sensor supply voltage between A +8 V digital supply and B sensor return is 8.0 0.4 VDC.Results:
OK - The supply voltage is reaching the sensor. Proceed to Test Step 4.
Not OK - The digital sensor supply voltage is not reaching the sensor.Repair: Refer to the diagnostic functional test Troubleshooting, "Digital Sensor Supply Circuit - Test" for the appropriate troubleshooting procedure.STOPTest Step 4. Check for Active Diagnostic Codes
Turn the keyswitch to the ON position.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.Note: Wait at least 15 seconds in order for the diagnostic codes to become active.Expected Result:No diagnostic codes are active.Results:
OK - No diagnostic codes are active.Repair: The problem may have been related to a faulty connection in the harness. Carefully reinspect the connectors and wiring. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".STOP
Active 1836-04 code - A 1836-04 diagnostic code is active. Proceed to Test Step 5.
Active 1836-03 code - A 1836-03 diagnostic code is active. Proceed to Test Step 6.Test Step 5. Check for a Short in the Signal Wire
Disconnect the following connectors.
P114/J114 auxiliary temperature sensor connectors
J1/P1 ECM connectors
J2/P2 ECM connectors
Measure the resistance between terminal P2-25 (auxiliary temperature sensor signal) and every terminal on the P1 and P2 connectors.Wiggle the harness during each measurement in order to locate any opens or shorts in the harness.
Measure the resistance between the suspect sensor's signal wire and engine ground.Expected Result:Each check indicated an open circuit.Results:
OK - Each check of the resistance indicated an open circuit. Proceed to Test Step 6.
Not