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HOMESERVICE MANUALSFORD2005TAURUS SEL, 4D SEDANREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1484 (ENGINE CONTROLS - PINPOINT TESTS (HYBRID))PINPOINT TEST KT: MOTOR ELECTRONICS COOLING SYSTEM (MECS) PUMPTEST PROCEDURE
2005 Ford Taurus SEL, 4D Sedan

Test Procedure

2005 Ford Taurus SEL, 4D SedanSECTION Test Procedure
WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, 2011 Ford Fusion, 2010 Mercury Milan, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
  1. KT1 DTC P0A05: VERIFY THE CONCERN IS MECS PUMP RELATED 
    NOTE: The DTC P0A05 may be set as the result of the PCM taking a limited operating strategy (LOS) action.

    The PCM DTCs P1A0C, P1A0D, P1145, and P2279 present along with P0A05 indicate that actual concern is not MECS pump related.

    Are the PCM DTCs P1A0C, P1A0D, P1145, and P2279 present during self-test? 

    Yes No
    DTC P0A05 was not set because of MECS pump related failure.
    DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .    		 DTC P0A05 was set because of MECS pump related failure.
    GO to  KT2.
  2. KT2 DTC P0A05: VERIFY THE CONCERN IS PRESENT 

    Is DTC P0A05 present in the KOEO or KOER self-test? 

    Yes No
    GO to  KT3. GO to  KT9.
  3. KT3 CHECK THE FUNCTIONALITY OF THE MECS PUMP RELAY CIRCUIT 
    • Ignition OFF.
    • MECS Pump Relay connector disconnected.
    • Connect a non-powered test lamp between:
      CONNECTOR PINS REFERENCE CHART

      Point A Vehicle Battery Point B MECS Pump Relay Connector, Harness Side
      Positive terminal MECSPR - Pin 2
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the MECP (MODE) PID.
    • Cycle the MECP PID on and off.

    Does the test lamp turn on and off when output state control is commanded on and off? 

    Yes No
    GO to  KT4. GO to  KT6.
  4. KT4 CHECK THE VPWR VOLTAGE TO THE MECS PUMP RELAY 
    • Measure the voltage between:
    VOLTAGE REFERENCE CHART

    (+) MECS Pump Relay Connector, Harness Side (-) Vehicle Battery
    VPWR - Pin 3 Negative terminal

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KT5. REPAIR the circuit. CHECK the condition of related fuses/fuse links. If damaged, CHECK the VPWR circuit for a short to ground.
    Clear the PCM DTCs. REPEAT the self-test.
  5. KT5 CHECK THE MECS PUMP RELAY RESISTANCE 
    • Ignition OFF.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) MECS Pump Relay Connector, Component Side (-) MECS Pump Relay Connector, Component Side
    VPWR - Pin 3 MECSPR - Pin 2

    Is the resistance between 40 - 90 ohms? 

    Yes No
    Unable to duplicate or identify the concern at this time.
    GO to  KT9.    		 INSTALL a new MECS Pump relay. Clear the PCM DTCs. REPEAT the self-test.
  6. KT6 CHECK THE MECS PUMP RELAY CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • PCM connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    VOLTAGE REFERENCE CHART

    (+) PCM Connector, Harness Side (-) Vehicle Battery
    MECSPR - Pin T49 Negative terminal

    Is the voltage less than 1 V? 

    Yes No
    GO to  KT7. REPAIR the circuit.
    Clear the PCM DTCs. REPEAT the self-test.
  7. KT7 CHECK THE MECS PUMP RELAY CIRCUIT FOR AN OPEN CIRCUIT IN THE HARNESS 
    • Ignition OFF.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) MECS Pump Relay Connector, Harness Side (-) PCM Connector, Harness Side
    MECSPR - Pin 2 MECSPR - Pin T49

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  KT8. REPAIR the circuit.
    Clear the PCM DTCs. REPEAT the self-test.
  8. KT8 CHECK THE MECS PUMP RELAY CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) PCM Connector, Harness Side (-) Vehicle Battery
    MECSPR - Pin T49 Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KT10. REPAIR the circuit.
    Clear the PCM DTCs. REPEAT the self-test.
  9. KT9 CHECK THE MECS PUMP RELAY CIRCUIT FOR AN INTERMITTENT CONCERN 
    • PCM connector connected.
    • MECS Pump Relay connector connected.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the MECP (MODE) PID.
    • Command the MECP ON.
    • Access the PCM and monitor the MECP_F (MODE) PID.

    Is a concern present during the wiggle test? 

    Yes No
    REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to PINPOINT TEST Z .
  10. KT10 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.
    • Verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new PCM.
    REFER to FLASH 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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