ECD SYSTEM, Diagnostic DTC:P0101

DTC Code DTC Name
P0101 Mass or Volume Air Flow Circuit Range / Performance Problem

DESCRIPTION

Refer to DTC P0102 Click here.

P0101
DTC Detection Drive Pattern DTC Detection Condition Trouble Area

All of the following conditions are met:


  • Driving in 3rd gear with warm engine

  • Decelerate from more than 2600 rpm to 1200 rpm when accelerator pedal fully released

Actual value of MAF rate exceeds the threshold for 3 seconds or more

(2 trip detection logic)


  • Open or short in mass air flow meter circuit

  • Intake mass air flow meter

  • Contamination in intake mass air flow meter

  • Turbo pressure sensor

  • EGR valve assembly

  • Open or short in EGR circuit

  • EGR passage

  • Open or short in diesel throttle motor circuit

  • Diesel throttle body assembly

  • Vacuum hose

  • ECM

Related Data List
DTC No. Data List
P0101 MAF

Tech Tips


  • If DTC P0101 is stored, the following symptoms may appear:


    • Black smoke

    • Poor acceleration

    • Combustion noise worsens

    • Lack of power due to a fail-safe operation

CAUTION / NOTICE / HINT

Note


  • When replacing the ECM, the ECM needs Registration and Initialization Click here.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips


  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the intelligent tester. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the tester display.

  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0101)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / DTC.

    4. Read DTCs.

      Result
      Result Proceed to
      DTC P0101 A
      DTC P0101 and other DTCs B

      Tech Tips

      If any DTCs other than P0101 are output, troubleshoot those DTCs first.


    B
    A
  2. CHECK CONNECTION OF VACUUM HOSES

    Tech Tips


    • Check the vacuum hose connection of the turbo pressure sensor.

    • Check that there is no air leak of the turbo pressure sensor vacuum hose.

      OK
      The vacuum hoses are appropriately connected to each other.

    NG
    OK
  3. READ VALUE USING INTELLIGENT TESTER (MAF)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / MAF and Coolant Temp.

    4. Allow the engine to idle until the Coolant Temp reaches 75°C (167°F) or more.

    5. Read the MAF with the engine in an idling condition and at an engine speed of 2000 rpm.

      Standard
      Item Condition Specified Condition
      MAF Idling (EGR valve open) 3.5 to 7 g/sec
      Idling (EGR valve close) 8 to 12 g/sec
      2000 rpm 10 to 40 g/sec

      Tech Tips


      • The shift lever should be in N and the A/C switch and all accessory switches should be off.

      • When reading the values of Data List, confirm that PM regeneration is not activating (value of "After Injection Period" is 0) by entering the following menus: Powertrain / Engine and ECT / Data List / After Injection Period.

        If PM regeneration is activating (value of "After Injection Period" is not 0), drive the vehicle until the PM regeneration is complete (value of "After Injection Period" becomes 0).

      • When idling, EGR cut occurs under either of the following conditions:


        • PM regeneration is activating.

        • Idling time is long (approximately 20 minutes or more).

      If EGR is cut off when idling and PM regeneration is not activating, when the vehicle is driven in 5th gear at 70 km/h for 10 minutes, EGR resumes.


    NG
    OK
  4. CHECK INTAKE AND EXHAUST SYSTEM


    1. Check for air leaks and any blockages between the air cleaner case and the turbocharger, and between the turbocharger and the intake manifold.

      OK
      No air leak or blockages.

    NG
    OK
  5. READ VALUE USING INTELLIGENT TESTER (MAP AND ATMOSPHERE PRESSURE)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / MAP and Atmosphere Pressure.

    4. Compare the values when the ignition switch is ON.

      Standard
      Difference between the MAP and the Atmosphere Pressure is less than 7 kPa.

      Tech Tips

      Standard atmospheric pressure is 101 kPa. For every 100 m increase in altitude, pressure drops by 1 kPa. Varies by weather.


    NG
    OK
  6. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DIESEL THROTTLE TARGET ANGLE)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Diesel Throttle Target Angle.

    4. When changing the Active Test value from 0 to 90%, check that Actual Throttle Position smoothly changes to the set opening angle.

      OK
      Value smoothly changes to the set opening angle.

    NG
    OK
  7. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

    4. When changing the Active Test value from 0 to 100%, check that Actual EGR Valve Pos. smoothly changes to the set opening angle.

      OK
      Value smoothly changes to the set opening angle.

    NG
    OK
  8. REPLACE INTAKE MASS AIR FLOW METER ASSEMBLY


    1. Replace the intake mass air flow meter assembly Click here.


    NEXT
  9. REPLACE DIESEL THROTTLE BODY ASSEMBLY


    1. Replace the diesel throttle body assembly Click here.

    2. Turn the ignition switch from ON to OFF and wait for 30 seconds or more.


    NEXT
  10. REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY


    1. Replace the electric EGR valve assembly Click here.

    2. Turn the ignition switch to ON.

    3. Turn the ignition switch off and wait for 30 seconds of more.


    NEXT
  11. REPLACE TURBO PRESSURE SENSOR


    1. Replace the turbo pressure sensor Click here.


    NEXT
  12. REPAIR OR REPLACE VACUUM HOSE


    NEXT
  13. REPAIR OR REPLACE INTAKE AND EXHAUST SYSTEM


    NEXT
  14. CHECK WHETHER DTC OUTPUT RECURS (DTC P0101)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Clear the DTCs Click here.

    4. Start the engine and ward it up until the engine coolant temperature sensor reaches 70°C (158°F) or more.

    5. Drive the vehicle in 3rd gear, decelerate from more than 2600 rpm to 1200 rpm when accelerator pedal fully released.

    6. Enter the following menus: Powertrain / Engine and ECT / DTC.

    7. Confirm that the DTC is not output again.


    NEXT