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Home >> Ford >> 2000 >> Contour SE, 2.0 3, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 2801 (Engine Controls - (Hybrid) - Pinpoint Tests A - Dr) >> PINPOINT TEST DN: Motor Electronics Coolant Temperature (MECT) Sensor >> Test Procedure

Test Procedure

WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
  1. DN1 DTCS P0A00, P0A01, P0A02, P0A03 AND P0A7C: CHECK FOR SELF-TEST DTCS 
    • Are DTCs P0A00, P0A01, P0A02, P0A03, or P0A7C present during PCM or transaxle control module (TCM) self-test? 
    Yes No
    For DTCs P0A00 and P0A7C, GO to  DN2.
    For DTC P0A01, GO to  DN14.
    For KOEO and KOER DTC P0A02, GO to  DN9.
    For KOEO and KOER DTC P0A03, GO to  DN5.
    For continuous memory DTCs P0A02 or P0A03, GO to  DN11.    		 Unable to duplicate or identify the concern at this time.
    RETURN to the SYMPTOM CHARTS article, Symptom Charts for further direction.
  2. DN2 DTCS P0A00 AND P0A7C: VISUALLY INSPECT THE MOTOR ELECTRONICS COOLING SYSTEM 
    NOTE: Repair any motor electronics coolant pump (MECP) DTCs before proceeding.
    • Visually inspect the motor electronics cooling system for leaks, pinched hoses, restricted radiator air flow, correct coolant level, fan operation, and loose electrical connections.
    • Is the motor electronics cooling system OK? 
    Yes No
    GO to  DN3. Refer to TRANSAXLE/TRANSMISSION COOLING - HYBRID to diagnose the motor electronics cooling system overheating concern.
  3. DN3 ROAD TEST THE VEHICLE AND MONITOR THE MECT_V PID 
    NOTE: Refer to the chart at the beginning of this pinpoint test for voltage specifications.
    • Access the PCM and monitor the MECT_V PID.
    • Road test the vehicle with heavy loads on the vehicle such as the A/C on MAX, the headlamps on, and the rear window defroster on.
    • Does the MECT sensor operate in the normal temperature range? 
    Yes No
    GO to  DN11. GO to  DN4.
  4. DN4 CHECK THE RESISTANCE OF THE MECT SENSOR 
    NOTE: Refer to the table at the beginning of this pinpoint test for temperature versus resistance specifications.
    • MECT Sensor connector disconnected.
    • Measure the resistance between:
      ( + ) MECT Sensor Connector, Component Side ( - ) MECT Sensor Connector, Component Side
      MECT - Pin 1 SIGRTN-C - Pin 2
    • Does the resistance of the MECT sensor match the ambient engine coolant temperature? 
    Yes No
    Refer to TRANSAXLE/TRANSMISSION COOLING - HYBRID to diagnose the motor electronics cooling system overheating concern. INSTALL a new MECT sensor. CLEAR the DTCs. REPEAT the self-test.
  5. DN5 DTC P0A03: CHECK THE MECT CIRCUIT FOR A SHORT TO PWR IN THE HARNESS 
    • MECT Sensor connector disconnected.
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) MECT Sensor Connector, Harness Side ( - )
      MECT - Pin 1 Ground
    • Is the voltage less than 5 V? 
    Yes No
    GO to  DN6. REPAIR the circuit.
    CLEAR the DTCs. REPEAT the self-test. CHECK MECT sensor for damage.
    GO to  DN6.
  6. DN6 CHECK THE RESISTANCE OF THE MECT SENSOR WITH THE ENGINE OFF 
    NOTE: Refer to the chart at the beginning of this test for the resistance specifications.
    • Key in OFF position.
    • Measure the resistance between:
      ( + ) MECT Sensor Connector, Component Side ( - ) MECT Sensor Connector, Component Side
      MECT - Pin 1 SIGRTN-C - Pin 2
    • Is the resistance within specification? 
    Yes No
    GO to  DN7. INSTALL a new MECT sensor. CLEAR the DTCs. REPEAT the self-test.
  7. DN7 CHECK THE SIGNAL AND SIGRTN CIRCUITS FOR AN OPEN IN THE HARNESS 
    • Key in OFF position.
    • Measure the resistance between:
      ( + ) MECT Sensor Connector, Harness Side ( - ) PCM Connector, Harness Side
      MECT - Pin 1 MECT - Pin T3
      SIGRTN-C - Pin 2 SIGRTN-C - Pin B41
    • Is each resistance less than 5 ohms? 
    Yes No
    GO to  DN8. REPAIR the circuit.
    CLEAR the DTCs. REPEAT the self-test.
  8. DN8 CHECK THE SENSOR SIGNAL FOR A SHORT TO VREF 
    • Key in OFF position.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) PCM Connector, Harness Side
      MECT - Pin T3 VREF - Pin B40
    • Is the resistance greater than 10K ohms? 
    Yes No
    GO to  DN17. REPAIR the circuit.
    CLEAR the DTCs. REPEAT the self-test.
  9. DN9 DTC P0A02: SIMULATE AN OPPOSITE SIGNAL TO THE PCM 
    • MECT Sensor connector disconnected.
    • Key ON, engine OFF.
    • Access the PCM and monitor the MECT_V PID.
    • Is the voltage greater than 4.2 V? 
    Yes No
    INSTALL a new MECT sensor. CLEAR the DTCs. REPEAT the self-test. GO to  DN10.
  10. DN10 CHECK THE SENSOR SIGNAL FOR A SHORT TO GROUND 
    • Key in OFF position.
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) MECT Sensor Connector, Harness Side ( - ) PCM Connector, Harness Side
      MECT - Pin 1 SIGRTN-C - Pin B41
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) Vehicle Battery
      MECT - Pin T3 Negative terminal
    • Are the resistances greater than 10,000 ohms? 
    Yes No
    GO to  DN17. REPAIR the circuit.
    CLEAR the DTCs. REPEAT the self-test.
  11. DN11 CONTINUOUS MEMORY DTCS P0A00, P0A02, P0A03 AND P0A7C: CHECK THE MECT SENSOR FOR AN INTERMITTENT CONCERN 
    • Key ON, engine OFF.
    • Access the PCM and monitor the MECT_V PID.
    • While observing the PID, carry out the following:
      • Tap on the sensor to simulate road shock
      • Wiggle the sensor connector
    • Does the MECT_V PID voltage indicate a concern in the MECT sensor? 
    Yes No
    DISCONNECT and INSPECT the connector.
    If OK, INSTALL a new MECT sensor.
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  DN12.
  12. DN12 CHECK THE MECT CIRCUIT FOR AN INTERMITTENT CONCERN 
    • Access the PCM and monitor the MECT_V PID.
    • While observing the PID, wiggle, shake, and bend small sections of the wiring harness working from the sensor to the PCM.
    • Does the MECT_V PID voltage indicate a concern in the MECT circuit? 
    Yes No
    ISOLATE the concern and REPAIR as necessary.
    CARRY OUT the Comprehensive Component Monitor Drive Cycle. REFER toON BOARD DIAGNOSTIC (OBD) DRIVE CYCLE .    		 GO to  DN13.
  13. DN13 CHECK THE PCM AND VEHICLE HARNESS CONNECTORS 
    • PCM connector disconnected.
    • MECT Sensor connector disconnected.
    • Are the connectors and terminals OK? 
    Yes No
    Unable to duplicate or identify the concern at this time.
    refer to PINPOINT TEST Z .    		 REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test.
  14. DN14 DTC P0A01: CHECK FOR THE PRESENCE OF PCM DTCS P0A00, P0A02, P0A03, P0A7C 
    NOTE: The TCM DTC P0A01 may be stored as a result of the MECT sensor or a corresponding circuit concern.

    The PCM DTCs P0A00, P0A02, P0A03, or P0A7C present along with a P0A05 indicate the MECT sensor or harness concern.

    • Are any of the above listed DTCs present? 
    Yes No
    DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO toDIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS . GO to  DN15.
  15. DN15 VERIFY THAT THE CONCERN IS PRESENT 
    NOTE: Clearing the TCM DTCs will erase any TCM recorded freeze frame data. Make sure to record any TCM freeze frame information before proceeding any further. Refer to the scan tool instruction manual for freeze frame PID menu.
    • Clear and retrieve the TCM continuous DTCs.
    • Is DTC P0A01 present? 
    Yes No
    GO to  DN16. Unable to duplicate or identify the concern at this time.
  16. DN16 CHECK THE TCM MECT PID 
    • Key ON, engine OFF.
    • Access the TCM and monitor the MECT PID.
    • Start the engine using the engine running diagnostic mode. Refer to Section 2 DIAGNOSTIC MODES .
    • Turn on all optional electrical loads.
    • Idle the engine for 5 minutes with the load on and monitor the MECT PID.
    • Does the MECT PID temperature increase by at least 1 degree? 
    Yes No
    INSTALL a new transaxle assembly. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - ELECTRONICALLY CONTROLLED CONTINUOUSLY VARIABLE TRANSMISSION (ECVT) . GO to  DN17.
  17. DN17 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the PCM self-test and verify the concern is still present.
    • Is the concern still present? 
    Yes No
    INSTALL a new PCM.
    REFER toFLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .    		 The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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