40056 85 Mercury SCREW, (M4 x 10)

Illustration 1 g01099399
Schematic for engine temperature sensors
Illustration 2 g01099400
P2 ECM connector
(P2-13) Engine coolant temperature
(P2-30) Common for the engine temperature sensors
(P2-56) Intake manifold air temperature
(P2-62) Fuel temperature
Illustration 3 g01099401
P1 ECM connector
(P1-18) Sensor common #1
(P1-26) Ambient air temperature sensor
Illustration 4 g01104079
Sensor locations
(1) Fuel temperature sensor
(2) Intake manifold air temperature sensor
Illustration 5 g01104077
Sensor locations
(3) Coolant temperature sensor Test Step 1. INSPECT ELECTRICAL CONNECTORS AND WIRING
Turn the keyswitch to the OFF position.
Thoroughly inspect the J2/P2 ECM connector, the J1/P1 ECM connector, and the suspect sensor connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the sensor connector and the ECM connector that are associated with the active diagnostic code.
Verify that the latch tab of the connector is properly latched.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and wiring for abrasions and for pinch points from the sensor 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 connectors 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 DIAGNOSTIC CODES
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
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.
Determine if the problem is related to an open circuit diagnostic code 03 or a short circuit diagnostic code 04. 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 Troubleshooting, "Electrical Connectors - Inspect" for additional information.STOP
Not OK - A short circuit diagnostic code 04 is active at this time. Proceed to Test Step 3.
Not OK - An open circuit diagnostic code 03 is active at this time. Proceed to Test Step 4.Test Step 3. DISCONNECT THE SUSPECT SENSOR IN ORDER TO CREATE AN OPEN CIRCUIT
Turn the keyswitch to the OFF position.
Disconnect the suspect sensor from the harness at the sensor connector.
Turn the keyswitch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes.
Access the "Active Diagnostic Codes" screen on Cat ET and check for an active open circuit diagnostic code 03 for the suspect sensor.
Turn the keyswitch to the OFF position. Expected Result:An open circuit diagnostic code 03 is now active for the suspect sensor.Results:
OK - A short circuit diagnostic code 04 was active before disconnecting the sensor. An open circuit diagnostic code 03 became active after disconnecting the sensor.Repair: Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine. Verify that there are no active diagnostic codes for the sensor. If there are no active diagnostic codes for the sensor, permanently install the new sensor. Clear any logged diagnostic codes.Verify that the repair eliminates the problem.STOP
Not OK - The short circuit diagnostic code 04 is still present. The short circuit is between the sensor harness connector and the ECM. Leave the sensor disconnected. Proceed to Test Step 7.Test Step 4. CHECK THE PULL-UP VOLTAGE AT THE SENSOR CONNECTOR
Disconnect the suspect sensor at the sensor connector.
Turn the keyswitch to the ON position.
Measure the voltage between terminal 1 (signal) and terminal 2 (sensor common) at the sensor connector.
Turn the keyswitch to the OFF position. Expected Result:The voltage is 5.5 0.5 VDC.Results:
OK - The voltage is 5.5 0.5 VDC. The correct pull-up voltage is present at the suspect sensor connector.Repair: The open circuit is in the sensor or the wire between the sensor and the sensor connector. Replace the sensor. Do not install the sensor in the engine. Verify that no diagnostic codes are active for the suspect sensor before permanently installing the sensor.STOP
Not OK - The voltage is not 5.5 0.5 VDC. Proceed to Test Step 5.Test Step 5. CHECK THE SIGNAL WIRE FOR A SHORT CIRCUIT
Turn the keyswitch to the OFF position.
Disconnect ECM connec