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Test Procedure

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  1. F1 PRELIMINARY DIAGNOSIS 
    NOTE: Diagnose circuit DTCs before range or performance DTCs.

    Are DTCs P0111, P0112 or P0113 present? 

    Yes No
    GO to F2  . RETURN to ENGINE CONTROLS - SYMPTOM CHARTS (DIESEL) , Symptom Charts for further direction.
  2. F2 CHECK FOR VOLTAGE AT THE SENSOR 
    • Ignition OFF.
    • MAF/IAT Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) MAF/IAT Sensor Connector, Harness Side (-)
      VPWR - Pin 3 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to F3  . REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  3. F3 CHECK FOR AN OPEN 
    • Ignition OFF.
    • PCM-B connector disconnected.
    • Measure the resistance between:
      (+) MAF/IAT Sensor Connector, Harness Side (-) PCM-B Connector, Harness Side
      IAT - Pin 2 IAT - Pin 47
      SIGRTN - Pin 4 SIGRTN - Pin 60

    Are the resistances less than 5 ohms? 

    Yes No
    GO to F4  . REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  4. F4 CHECK FOR A SHORT TO GROUND 
    • Measure the resistance between:
      (+) MAF/IAT Sensor Connector, Harness Side (-)
      IAT - Pin 2 Ground
    • Measure the resistance between:
      (+) MAF/IAT Sensor Connector, Harness Side (-) MAF/IAT Sensor Connector, Harness Side
      IAT - Pin 2 SIGRTN - Pin 4

    Are the resistances less than 5 ohms? 

    Yes No
    GO to F5  . REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.
  5. F5 CHECK FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) MAF/IAT Sensor Connector, Harness Side (-)
      IAT - Pin 2 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to F6  .
  6. F6 INTERMITTENT CHECK 
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the IAT11_V (VOLT) PID.
    • While observing the PID, carry out the following:
      • Wiggle all accessible harness from the MAF/IAT sensor to the PCM and lightly tap on the sensor.
      • Wiggle the MAF/IAT sensor connector.
      • Look for sudden changes in the voltage when the harness and connector are wiggled or when the MAF/IAT sensor is tapped.

    Is a concern present? 

    Yes No
    REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.
    GO to F7  .
  7. F7 TEMPERATURE SENSOR CORRELATION 
    NOTE: Check temperature values while engine is at ambient temperature, cold soak the engine for a minimum of 8 hours if necessary.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the AAT (TEMP), CAC_T (TEMP), IAT11 (TEMP), ECT2 (TEMP) and EGRT11 (TEMP) PIDs.
    • The IAT11 temperature must be within the following ranges:
      • Within 15°C (27°F) degrees of the AAT reading
      • Within 16°C (28.8°F) degrees of the CAC_T reading
      • Within 20°C (36°F) degrees of the ECT2 reading
      • Within 20°C (36°F) degrees of the EGRT11 reading

    Is the IAT11 PID within specification? 

    Yes No
    Unable to duplicate the condition. CHECK for a loose connection, and damaged or corroded terminals. WIGGLE the harness attempting to recreate the concern. REPAIR as necessary. INSTALL a new MAF/IAT sensor. REFER to the appropriate Electronic Engine Controls article. Clear the PCM DTCs. REPEAT the self-test. If the concern or DTC is still present,
    GO to F8  .
  8. F8 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.