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Home >> Mercury >> 2006 >> Montego Base, AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Pinpoint Test DK: Accelerator Pedal Position (App) Sensor Through Pinpoint Test DW: Heated Oxygen Sensor (Ho2S) - (Except Diesel & Hybrid) >> Pinpoint Test DU: Intake Air Temperature 2 (IAT2) Sensor >> Test Procedure

Test Procedure

  1. DU1 CHECK FOR DTCS 

    Are DTCs P0127, P1114, or P1115 present? 

    Yes No
    For DTC P0127, GO to  DU8.
    For DTC P1114, GO to  DU6.
    For DTC P1115, GO to  DU2.    		 For all others, GO to POWERTRAIN DTC CHARTS & DESCRIPTIONS .
  2. DU2 DTC P1115: SIMULATE AN OPPOSITE SIGNAL TO THE PCM 
    • The DTC indicates the sensor signal is greater than the self-test maximum.
    • IAT2 Sensor connector disconnected.
    • Key ON, engine OFF.
    • Connect a 5 amp fused jumper wire between the following:
    Point A IAT2 Sensor Connector, Harness Side Point B IAT2 Sensor Connector, Harness Side
    IAT2 - Pin 1 SIGRTN - Pin 2

    Does a diagnostic tool communication concern exist?  

    Yes No
    GO to  DU5. GO to  DU3.
  3. DU3 CHECK FOR AN OPPOSITE SIGNAL TO THE PCM 
    • With the jumper installed.
    • Access the PCM and monitor the IAT2 V 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 DTCs. REPEAT the self-test. GO to  DU4.
  4. DU4 CHECK THE SIGNAL AND SIGRTN CIRCUITS FOR AN OPEN IN THE HARNESS 
    • Key in OFF position.
    • Remove the jumper wire(s).
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) IAT2 Sensor Connector, Harness Side ( - ) PCM Connector, Harness Side
      IAT2 - Pin 1 IAT2 - Pin 37
      SIGRTN - Pin 2 SIGRTN - Pin 91

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  DU12. REPAIR the open circuit. CLEAR the DTCs.
    REPEAT the self-test.
  5. DU5 CHECK THE SENSOR SIGNAL FOR A SHORT TO VREF 
    • Key in OFF position.
    • Remove the jumper wire(s).
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) PCM Connector, Harness Side
      IAT2 - Pin 37 VREF - Pin 90

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DU12. REPAIR the short circuit to VREF. CLEAR the DTCs. REPEAT the self-test.
  6. DU6 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.
    • Key ON, engine OFF.
    • Access the PCM and monitor the IAT2 V PID.

    Is the resistance greater than 10K ohms? 

    Yes No
    INSTALL a new IAT2 sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article. CLEAR the DTCs. REPEAT the self-test. GO to  DU7.
  7. DU7 CHECK THE SENSOR SIGNAL FOR A SHORT TO GROUND 
    • Key in OFF position.
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) PCM Connector, Harness Side
      IAT2 - Pin 37 SIGRTN - Pin 91
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) 12 Volt Vehicle Battery
      IAT2 - Pin 37 Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
     
    GO to  DU12.    		 REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  8. DU8 DTC P0127: CHECK CHARGE AIR COOLER PUMP OPERATION 

    Does the supercharger intercooler pump run? 

    Yes No
    GO to  DU9. DIAGNOSE the charge air cooler (CAC) pump.
    GO to Pinpoint Test KP step 9 .
  9. DU9 CHECK THE INTERCOOLER SYSTEM 
    • Check intercooler system for low fluid level, cracked, blocked or misrouted coolant lines, cracked or blocked heat exchanger.

    Is the concern still present? 

    Yes No
    REFER to the appropriate SUPERCHARGER COOLING article. REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test. .    		 GO to  DU10.
  10. DU10 SIMULATE THE HIGH IAT2 SIGNAL TO THE PCM  
    • Key ON, engine OFF.
    • Access the PCM and monitor the IAT2 V PID.
    • Observe the PID while disconnecting the IAT2 sensor.

    Is the voltage greater than 4.2 V? 

    Yes No
    GO to  DU11. GO to  DU12.
  11. DU11 SIMULATE THE LOW IAT2 SIGNAL TO THE PCM  
    • Key in OFF position.
    • IAT2 Sensor connector disconnected.
    • Connect a 5 amp fused jumper wire between the following:
      Point A IAT2 Sensor Connector, Harness Side Point B IAT2 Sensor Connector, Harness Side
      IAT2 - Pin 1 SIGRTN - Pin 2
    • Key ON, engine OFF.
    • Access the PCM and monitor the IAT2 V 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 DTCs. REPEAT the self-test. GO to  DU12.
  12. DU12 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 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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