ECD SYSTEM, Diagnostic DTC:P0101

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

DESCRIPTION

Refer to DTC P0100.

Click here

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0101 Mass Air Flow Circuit Range / Performance Problem

After the engine is completely warmed up, while the accelerator pedal is released for 7 seconds or more and the vehicle is decelerating, the intake air volume is higher or lower than the threshold* (EGR valve fully closed and throttle valve is fully open).

(2 trip detection logic)

*: There is a threshold for a low air flow rate malfunction and high air flow rate malfunction. The threshold is different depending on the values of "Engine Speed", "MAP" and "Intake Air Temp (Turbo)".

  • Mass air flow meter sub-assembly

  • Intake air temperature sensor (turbo)

  • Manifold absolute pressure sensor

  • Electric EGR control valve assembly

  • ECM

  • Open or short in mass air flow meter sub-assembly circuit

 Comes on DTC stored

Tech Tips


  • Low air flow rate malfunction: For example when vehicle deceleration if "MAF" is 25 gm/sec or less, low air flow malfunction is confirmed (at "Engine Speed" is 1600 rpm, "MAP" is 110 kPa and "Intake Air Temp (Turbo)" is 35°C).

  • High air flow rate malfunction: For example when vehicle deceleration if "MAF" is 46 gm/sec or more, high air flow malfunction is confirmed (at "Engine Speed" is 1600 rpm, "MAP" is 110 kPa and "Intake Air Temp (Turbo)" is 35°C).

Related Data List
DTC No. Data List
P0101

  • MAF

  • MAP

  • Engine Speed

  • Intake Air Temp (Turbo)

  • Target EGR Valve Pos

  • Actual EGR Valve Pos

  • EGR Close Lrn. Val.

Tech Tips

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


  1. As the ECU mistakenly determines that there is less air than the actual intake air amount, EGR is decreased to match the target EGR.


    • Combustion noise worsens

  2. As the ECU mistakenly determines that there is more air than the actual intake air amount, EGR is increased to match the target EGR:


    • Misfire

    • White smoke

    • Black smoke

CONFIRMATION DRIVING PATTERN

DTC No. DTC Detection Drive Pattern
P0101 After the engine is completely warmed up, perform the following procedure 3 times: from a vehicle speed of 60 km/h (37 mph), accelerate the vehicle to 80 km/h (50 mph), quickly release the accelerator pedal and do not depress it for 7 seconds or more.

CAUTION / NOTICE / HINT

Note

After replacing the ECM, the new ECM needs registration (Click here ) and initialization Click here.

Tech Tips

Read freeze frame data using the GTS. 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 OTHER DTC OUTPUT (IN ADDITION TO DTC P0101)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG) and turn the GTS on.

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

    4. Read the DTCs.


      Powertrain > Engine and ECT > Trouble Codes
      Result
      Result Proceed to
      P0101 and other DTCs are output A
      P0101 is output B

      Tech Tips

      If codes other than P0101 are output, perform troubleshooting for those DTCs first.


    A

    GO TO DTC CHART Click here

    B

  2. CHECK FREEZE FRAME DATA (MAF AND ENGINE SPEED)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    5. Check the freeze frame data.


      Powertrain > Engine and ECT > Trouble Codes
      Result
      Result Proceed to

      • Engine speed 1350 rpm or less

      • MAF 246.0 gm/sec or more

      		 A

      • Engine speed 1350 rpm or more

      • MAF 0.03 gm/sec or less
      Except above B

    B

    READ VALUE USING GTS (MAF AND ENGINE SPEED) Click here

    A

  3. READ VALUE USING GTS (MAF AND ENGINE SPEED)


    1. Connect the GTS to the DLC3.

    2. Start the engine and turn the GTS on.

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


      Powertrain > Engine and ECT > Data List
      Tester Display
      Engine Speed
      MAF

    4. Read the value.

      Standard
      Engine speed MAF
      Idling

      • 3 to 15 gm/sec (EGR on)

      • 10 to 21 gm/sec (EGR off)
      3000 rpm

      • 45 to 89 gm/sec (EGR on)

      • 72 to 94 gm/sec (EGR off)
      Result
      Proceed to
      OK
      NG

    NG

    GO TO STEP 13 Click here

    OK

  4. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY


    1. Replace the mass air flow meter sub-assembly.

      Click here

      Tech Tips

      If foreign matter is stuck inside the mass air flow meter sub-assembly, the output characteristics of the mass air flow meter sub-assembly may change, resulting in a malfunction.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK DTC OUTPUT


    1. Connect the GTS to the DLC3.

    2. Clear the DTCs.


      Powertrain > Engine and ECT > Clear DTCs

    3. Turn the engine switch off for 30 seconds or more.

    4. Start the engine.

    5. After the engine is completely warmed up, perform the following procedure 3 times with the A/C off: from a vehicle speed of 60 km/h (37 mph), accelerate the vehicle to 80 km/h (50 mph), quickly release the accelerator pedal and do not depress it for 7 seconds or more.

    6. Stop the vehicle immediately after completing the above procedure.

    7. Connect the GTS to the DLC3.

    8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    9. Read the pending DTCs.


      Powertrain > Engine and ECT > Trouble Codes

      Tech Tips


      • If no pending DTCs are output, proceed to the next step to check "All Readiness".

      • Perform the following procedure using the GTS to determine whether or not the DTC judgment has been carried out.


      1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.


        Powertrain > Engine and ECT > Utility
        Tester Display
        All Readiness

      2. Input DTC P0101.

      3. Check the DTC judgment result.

        Result
        GTS Display Result Proceed to
        Pending DTC P0101 is output B
        All Readiness NORMAL A
        ABNORMAL B

        Tech Tips

        If STATUS is INCOMPLETE or N/A, perform the following procedure again 3 times with the A/C off: from a vehicle speed of 60 km/h (37 mph), accelerate the vehicle to 80 km/h (50 mph), quickly release the accelerator pedal and do not depress it for 7 seconds or more.


    A

    END

    B

  6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)


    1. Disconnect the mass air flow meter sub-assembly connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A29-1 (FG) - C39-33 (VG) Always Below 1 Ω
      A29-2 (E2G) - C39-24 (EVG) Always Below 1 Ω
      A29-1 (FG) or C39-33 (VG) - Body ground and other terminals Always 10 kΩ or higher

    4. Reconnect the mass air flow meter sub-assembly connector.

    5. Reconnect the ECM connector.

      Result
      Proceed to
      OK
      NG

    NG

    GO TO STEP 19 Click here

    OK

  7. REPLACE ECM


    1. Replace the ECM.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 20 Click here

  8. READ VALUE USING GTS (MAF AND ENGINE SPEED)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG) and turn the GTS on.

    3. Start the engine and warm it up.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / MAF and Engine speed.


      Powertrain > Engine and ECT > Data List
      Tester Display
      Engine Speed
      MAF

    5. Read the value.

      Standard
      Engine speed MAF
      Idling

      • 3 to 15 gm/sec (EGR on)

      • 10 to 21 gm/sec (EGR off)
      3000 rpm

      • 45 to 89 gm/sec (EGR on)

      • 72 to 94 gm/sec (EGR off)
      Result
      Proceed to
      OK
      NG

    NG

    GO TO STEP 13 Click here

    OK

  9. READ VALUE USING GTS (MAP AND ATMOSPHERIC PRESSURE)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG) and turn the GTS on.

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


      Powertrain > Engine and ECT > Data List
      Tester Display
      Atmosphere Pressure
      MAP

    4. Compare the values when the engine switch on (IG).

      Standard
      Difference between "MAP" and "Atmosphere Pressure" is less than 8 kPa.

      Tech Tips


      • If "MAP" and "Atmosphere Pressure" have the same value, both are normal. If there is a difference of 8 kPa or more, compare the values to the atmospheric pressure for that day. The sensor whose deviation is the greatest is malfunctioning.

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

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

    OK

  10. CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leakage.

      Click here

      OK
      No leakage from intake system.

      Tech Tips


      • Check for abnormal disconnection, pipe and hose squashing, and any damage in the intake system.

      • Using your hand, check whether the pipes and hoses in the intake system are securely connected.

      • Air leaks from the intake system can be checked by applying soapy water and revving the engine.

      • Check for any modifications in the intake system made by the user.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE INTAKE SYSTEM Click here

    OK

  11. READ VALUE USING GTS (INTAKE AIR AND INTAKE AIR TEMP [TURBO])


    1. Connect the GTS to the DLC3.

    2. Soak the engine for a long time.

    3. Turn the engine switch on (IG) and turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air and Intake Air Temp (Turbo).


      Powertrain > Engine and ECT > Data List
      Tester Display
      Intake Air
      Intake Air Temp (Turbo)
      OK
      Intake Air is the same as Intake Air Temp (Turbo).
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT INTAKE AIR TEMPERATURE SENSOR (TURBO) Click here

    OK

  12. INSPECT ELECTRIC EGR CONTROL VALVE ASSEMBLY


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG) and turn the GTS on.

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


      Powertrain > Engine and ECT > Active Test
      Tester Display
      Control the EGR Step Position

    4. When changing the Active Test continuously value to 1, 30, 60, 90, 60, 30 and 1%, check that Actual EGR Valve Pos. smoothly changes to the set opening angle.

      OK
      Value smoothly changes to set opening angle.

    5. Enter the following menus: Powertrain / Engine and ECT / Data List / EGR Close Lrn. Val.


      Powertrain > Engine and ECT > Data List
      Tester Display
      EGR Close Lrn. Val.

    6. Read the values.

      Standard
      0 to 1 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT ELECTRIC EGR CONTROL VALVE ASSEMBLY Click here

    OK

  13. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)


    1. Disconnect the mass air flow meter sub-assembly connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A29-1 (FG) - C39-33 (VG) Always Below 1 Ω
      A29-2 (E2G) - C39-24 (EVG) Always Below 1 Ω
      A29-1 (FG) or C39-33 (VG) - Body ground and other terminals Always 10 kΩ or higher

    4. Reconnect the mass air flow meter sub-assembly connector.

    5. Reconnect the ECM connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  14. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY


    1. Replace the mass air flow meter sub-assembly.

      Click here

      Tech Tips

      If foreign matter is stuck inside the mass air flow meter sub-assembly, the output characteristics of the mass air flow meter sub-assembly may change, resulting in a malfunction.

      Result
      Proceed to
      NEXT

    NEXT

  15. CHECK DTC OUTPUT


    1. Connect the GTS to the DLC3.

    2. Clear the DTCs.


      Powertrain > Engine and ECT > Clear DTCs

    3. Turn the engine switch off for 30 seconds or more.

    4. Start the engine.

    5. After the engine is completely warmed up, perform the following procedure 3 times with the A/C off: from a vehicle speed of 60 km/h (37 mph), accelerate the vehicle to 80 km/h (50 mph), quickly release the accelerator pedal and do not depress it for 7 seconds or more.

    6. Stop the vehicle immediately after completing the above procedure.

    7. Connect the GTS to the DLC3.

    8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    9. Read the pending DTCs.


      Powertrain > Engine and ECT > Trouble Codes

      Tech Tips


      • If no pending DTCs are output, proceed to the next step to check "All Readiness".

      • Perform the following procedure using the GTS to determine whether or not the DTC judgment has been carried out.


      1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.


        Powertrain > Engine and ECT > Utility
        Tester Display
        All Readiness

      2. Input DTC P0101.

      3. Check the DTC judgment result.

        Result
        GTS Display Result Proceed to
        Pending DTC P0101 is output B
        All Readiness NORMAL A
        ABNORMAL B

        Tech Tips

        If STATUS is INCOMPLETE or N/A, perform the following procedure again 3 times with the A/C off: from a vehicle speed of 60 km/h (37 mph), accelerate the vehicle to 80 km/h (50 mph), quickly release the accelerator pedal and do not depress it for 7 seconds or more.


    A

    END

    B

    GO TO STEP 21 Click here

  16. INSPECT ELECTRIC EGR CONTROL VALVE ASSEMBLY


    1. Remove the electric EGR control valve assembly.

      Click here

    2. Visually check the electric EGR control valve assembly for deposits. If there are deposits, clean the electric EGR control valve assembly.

      Note


      • When cleaning the electric EGR control valve assembly, make sure the valve is completely closed.

      • Do not forcibly open the valve, as it may be damaged or deformed.

      • When cleaning the electric EGR control valve assembly, use a piece of cloth soaked with cleaning solvent. Spraying the solvent directly onto these parts or soaking the parts in the solvent may damage the parts.

    3. B003S2IC01
      *1 Gap
      *a OK
      *b NG

      Hold the electric EGR control valve assembly up to a light, and then from the side indicated by the arrow in the illustration, visually check that there is no gap between the valve and body.

      OK
      No light passes through (there is no gap between the valve and body).

      Tech Tips

      Light passes through part A shown in the illustration even if the valve is completely closed as there is an opening in the sealring of the valve, this is not a problem.

      If light passes through (there is a gap between the valve and body), replace the electric EGR control valve assembly.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY Click here

    OK

  17. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY


    1. Replace the mass air flow meter sub-assembly.

      Click here

      Tech Tips

      If foreign matter is stuck inside the mass air flow meter sub-assembly, the output characteristics of the mass air flow meter sub-assembly may change, resulting in a malfunction.

      Result
      Proceed to
      NEXT

    NEXT

  18. CHECK DTC OUTPUT


    1. Connect the GTS to the DLC3.

    2. Clear the DTCs.


      Powertrain > Engine and ECT > Clear DTCs

    3. Turn the engine switch off for 30 seconds or more.

    4. Start the engine.

    5. After the engine is completely warmed up, perform the following procedure 3 times with the A/C off: from a vehicle speed of 60 km/h (37 mph), accelerate the vehicle to 80 km/h (50 mph), quickly release the accelerator pedal and do not depress it for 7 seconds or more.

    6. Stop the vehicle immediately after completing the above procedure.

    7. Connect the GTS to the DLC3.

    8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    9. Read the pending DTCs.


      Powertrain > Engine and ECT > Trouble Codes

      Tech Tips


      • If no pending DTCs are output, proceed to the next step to check "All Readiness".

      • Perform the following procedure using the GTS to determine whether or not the DTC judgment has been carried out.


      1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.


        Powertrain > Engine and ECT > Utility
        Tester Display
        All Readiness

      2. Input DTC P0101.

      3. Check the DTC judgment result.

        Result
        GTS Display Result Proceed to
        Pending DTC P0101 is output B
        All Readiness NORMAL A
        ABNORMAL B

        Tech Tips

        If STATUS is INCOMPLETE or N/A, perform the following procedure again 3 times with the A/C off: from a vehicle speed of 60 km/h (37 mph), accelerate the vehicle to 80 km/h (50 mph), quickly release the accelerator pedal and do not depress it for 7 seconds or more.


    A

    END

    B

    REPLACE ECM Click here

  19. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.

      Result
      Proceed to
      NEXT

    NEXT

  20. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Clear the DTCs.


      Powertrain > Engine and ECT > Clear DTCs

    3. Turn the engine switch off for 30 seconds or more.

    4. Start the engine.

    5. After the engine is completely warmed up, perform the following procedure 3 times with the A/C off: from a vehicle speed of 60 km/h (37 mph), accelerate the vehicle to 80 km/h (50 mph), quickly release the accelerator pedal and do not depress it for 7 seconds or more.

    6. Stop the vehicle immediately after completing the above procedure.

    7. Connect the GTS to the DLC3.

    8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    9. Confirm that the pending DTC is not output again.


      Powertrain > Engine and ECT > Trouble Codes
      Result
      Proceed to
      NEXT

    NEXT

    END

  21. REPLACE ECM


    1. Replace the ECM.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 20 Click here

  22. REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY


    1. Replace the electric EGR control valve assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 20 Click here

  23. INSPECT INTAKE AIR TEMPERATURE SENSOR (TURBO)


    1. Inspect the intake air temperature sensor (turbo).

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    GO TO STEP 17 Click here

    NG

  24. REPLACE INTAKE AIR TEMPERATURE SENSOR (TURBO)


    1. Replace the intake air temperature sensor (turbo).

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 20 Click here

  25. REPAIR OR REPLACE INTAKE SYSTEM


    1. Repair or replace the intake system.

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 20 Click here

  26. REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR


    1. Replace the manifold absolute pressure sensor.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO STEP 20 Click here