SFI SYSTEM, Diagnostic DTC:P0101

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

DESCRIPTION

Refer to DTC P0102 Click here.

DTC No. DTC Detection Condition Trouble Area
P0101

Conditions (a), (b), (c), (d) and (e) are met (2 trip detection logic):

(a) Engine running

(b) Engine coolant temperature 70°C (158°F) or more

(c) Throttle position sensor voltage 0.2 V or more, and less than 2 V

(d) Average engine load value ratio less than 0.1, or more than 3.5 (varies with estimated engine load)

Average engine load value ratio = Average engine load based on mass air flow meter output / Average engine load estimated from driving conditions

(e) Average air-fuel ratio less than -20%, or more than 20%

  • Mass air flow meter

  • Intake system

  • PCV hose connections

MONITOR DESCRIPTION

The mass air flow meter is a sensor that measures the amount of air flowing through the throttle valve. The ECM uses this information to determine the fuel injection time and to provide an appropriate air fuel ratio. Inside the mass air flow meter, there is a heated platinum wire which is exposed to the flow of intake air. By applying a specific electrical current to the wire, the ECM heats it to a specific temperature. The flow of incoming air cools both the wire and an internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the voltage applied to these components of the mass air flow meter. The voltage level is proportional to the airflow through the sensor, and the ECM uses it to calculate the intake air volume.

The ECM monitors the average engine load value ratio to check the mass air flow meter for malfunctions. The average engine load value ratio is obtained by comparing the average engine load calculated from the mass air flow meter output to the average engine load estimated from the driving conditions, such as the engine speed and the throttle opening angle. If the average engine load value ratio is below the threshold value, the ECM determines that the intake air volume is low, and if the average engine load value ratio is above the threshold value, the ECM determines that the intake air volume is high.

If this is detected in 2 consecutive driving cycles, the MIL is illuminated and a DTC is set.

MONITOR STRATEGY

Required Sensors/Components (Main) Mass air flow meter
Required Sensors/Components (Related) Crankshaft position sensor, VVT sensor, engine coolant temperature sensor and throttle position sensor
Frequency of Operation Continuous

CONFIRMATION DRIVING PATTERN

B002BK1E14

  1. Connect the GTS to the DLC3.

  2. Turn the power switch on (IG).

  3. Turn the GTS on.

  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Click here.

  5. Turn the power switch off and wait for at least 30 seconds.

  6. Turn the power switch on (IG) and turn the GTS on.

  7. Put the engine in inspection mode (maintenance mode) Click here.

  8. Start the engine and warm it up until the engine coolant temperature reaches 70°C (158°F) or more [A].

  9. Drive the vehicle at approximately 80 km/h (50 mph) to 112 km/h (70 mph) for 5 minutes or more [B].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

    Tech Tips

    Drive while keeping the engine load as stable as possible.

  10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].

  11. Read Pending DTCs.

    Tech Tips


    • If a pending DTC is not output, perform the following procedure.

    • If a pending DTC is output, the system is malfunctioning.

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

  13. Input the DTC: P0101.

  14. Check the DTC judgment result.

    GTS Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU's memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or N/A, perform steps [B] and [C] again.

WIRING DIAGRAM

Refer to DTC P0102 Click here.

CAUTION / NOTICE / HINT

Tech Tips

Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


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


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

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

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P0101 is output A
      DTC P0101 and other DTCs are output B

      Tech Tips

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


    B

    GO TO DTC CHART Click here

    A

  2. CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leaks.

      OK
      No leaks from intake system.

      Tech Tips

      Perform "Inspection After Repair" after repairing or replacing the intake system Click here.


    NG

    REPAIR OR REPLACE INTAKE SYSTEM

    OK

  3. CHECK PCV HOSE CONNECTIONS


    1. Check the PCV hose connections.

      OK
      PCV hose is connected correctly and is not damaged.

    NG

    REPAIR OR REPLACE PCV HOSE

    OK

  4. REPLACE MASS AIR FLOW METER


    1. Replace the mass air flow meter Click here.

      Tech Tips

      Perform "Inspection After Repair" after replacing the mass air flow meter Click here.


    NEXT

  5. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Turn the power switch off and wait for at least 30 seconds.

    6. Turn the power switch on (IG) and turn the GTS on.

    7. Put the engine in inspection mode (maintenance mode) Click here.

    8. Start the engine and warm it up.

    9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

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

    11. Input the DTC: P0101.

    12. Check the DTC judgment result.

      Result
      GTS Display Description
      NORMAL

      • DTC judgment completed

      • System normal
      ABNORMAL

      • DTC judgment completed

      • System abnormal
      INCOMPLETE

      • DTC judgment not completed

      • Perform driving pattern after confirming DTC enabling conditions
      N/A

      • Unable to perform DTC judgment

      • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    NEXT

    END