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HOMESERVICE MANUALSFORD2004MUSTANG BASE, 2D COUPE, 3.9 6, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 2543 (ENGINE CONTROLS - PINPOINT TEST DL: CYLINDER HEAD TEMPERATURE (CHT) SENSOR THROUGH PINPOINT TEST DX: ENGINE COOLANT TEMPERATURE (ECT) SENSOR - (EXCEPT DIESEL & HYBRID))PINPOINT TEST DU: INTAKE AIR TEMPERATURE 2 (IAT2) SENSORTEST PROCEDURE
2004 Ford Mustang Base, 2D Coupe, 3.9 6, Automatic

Test Procedure

2004 Ford Mustang Base, 2D Coupe, 3.9 6, AutomaticSECTION Test Procedure
WARNING: This page does not describe the selected car, but rather 22 other vehicles, including the 2011 Mercury Milan, 2011 Mercury Mariner, 2011 Mercury Grand Marquis, 2011 Lincoln Town Car, and 2011 Lincoln Navigator L. However, it is still accessible from the selected car via links, so may be relevant.
  1. DU1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 

    Are DTCs P0097, P0098, P0127, P1114, or P1115 present? 

    Yes No
    For DTCs P0097 or P1114, GO to  DU4.
    For DTCs P0098 or P1115, GO to  DU2.
    For DTC P0127, GO to  DU6.    		 For all others, GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .
  2. DU2 CHECK FOR AN OPPOSITE SIGNAL TO THE PCM 
    • The DTC indicates the sensor signal is greater than the self-test maximum.
    • IAT2 Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Connect a 5 amp fused jumper wire between the following:
      CONNECTOR PINS REFERENCE CHART

      Point A IAT2 Sensor Connector, Harness Side Point B IAT2 Sensor Connector, Harness Side
      IAT2 - Pin 1 SIGRTN - Pin 2
    • Access the PCM and monitor the IAT2 (VOLT) PID.

    Is the voltage less than 0.2 V? 

    Yes No
    INSTALL a new IAT2 sensor. REFER to the appropriate Electronic Engine Controls article .
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DU3.
  3. DU3 CHECK THE SENSOR SIGNAL FOR A SHORT TO VREF 
    • Ignition OFF.
    • Remove the jumper wire(s).
    • PCM connector disconnected.
    • Measure the resistance between:
      RESISTANCE REFERENCE CHART

      (+) PCM Connector, Harness Side (-) PCM Connector, Harness Side
      IAT2 - Pin E36 VREF - Pin B52, E20, T31

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DU10. REPAIR the short circuit to VREF. Clear the PCM DTCs. REPEAT the self-test.
  4. DU4 DTC P1114: SIMULATE AN OPPOSITE SIGNAL TO THE PCM 
    • The DTC indicates the sensor signal is less than the self-test minimum.
    • IAT2 Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the IAT2 (VOLT) PID.

    Is the voltage greater than 4.2 V? 

    Yes No
    INSTALL a new IAT2 sensor. REFER to the appropriate Electronic Engine Controls article .
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DU5.
  5. DU5 CHECK THE SENSOR SIGNAL FOR A SHORT TO GROUND 
    • Ignition OFF.
    • PCM connector disconnected.
    • Measure the resistance between:
      RESISTANCE REFERENCE CHART

      (+) PCM Connector, Harness Side (-) PCM Connector, Harness Side
      IAT2 - Pin E36 SIGRTN - Pin B56, E32, T38
    • Measure the resistance between:
      RESISTANCE REFERENCE CHART

      (+) PCM Connector, Harness Side (-) 12 Volt Vehicle Battery
      IAT2 - Pin E36 Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DU10. REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.
  6. DU6 DTC P0127: CHECK CHARGE AIR COOLER PUMP (CAC) OPERATION 
    NOTE: Remove the fan control relays to disable the cooling fans so the pump can be heard. Disregard the cooling fan DTCs that will set as a result of this step.
    • Carry out the PCM KOEO self-test.

    Does the CAC pump cycle ON and OFF? 

    Yes No
    GO to  DU7. DIAGNOSE the CAC pump.
    GO to PINPOINT TEST KP step 8 .
  7. DU7 CHECK THE CHARGE AIR COOLER (CAC) SYSTEM 
    • Check the CAC system for low fluid level, cracked, blocked or misrouted coolant lines, cracked or blocked heat exchanger.

    Is a concern present? 

    Yes No
    REFER to the appropriate Supercharger Cooling article , to DIAGNOSE a loss of coolant. REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DU8.
  8. DU8 SIMULATE THE HIGH IAT2 SIGNAL TO THE PCM 
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the IAT2 (VOLT) PID.
    • Observe the PID while disconnecting the IAT2 sensor.

    Is the voltage greater than 4.2 V? 

    Yes No
    GO to  DU9. GO to  DU10.
  9. DU9 SIMULATE THE LOW IAT2 SIGNAL TO THE PCM 
    • Ignition OFF.
    • IAT2 Sensor connector disconnected.
    • Connect a 5 amp fused jumper wire between the following:
      CONNECTOR PINS REFERENCE CHART

      Point A IAT2 Sensor Connector, Harness Side Point B IAT2 Sensor Connector, Harness Side
      IAT2 - Pin 1 SIGRTN - Pin 2
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the IAT2 (VOLT) PID.

    Is the voltage less than 0.2 V? 

    Yes No
    CONNECT the sensor and GO to REFERENCE VALUES . COMPARE the IAT2 PID to reference values under different road test conditions. If the sensor is not in range, INSTALL a new IAT2 sensor. REFER to the appropriate Electronic Engine Controls article .
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DU10.
  10. DU10 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) , PROGRAMMING THE VID BLOCK FOR A REPLACEMENT PCM . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
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  • • The engine overheats, stalls repeatedly, or misfires under load.
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