ECD SYSTEM(w/ DPF), Diagnostic DTC:P0100

DTC Code DTC Name
P0100 Mass Air Flow Circuit Malfunction

DESCRIPTION

The mass air flow meter is a sensor that measures the intake air volume using the following built-in components:


Intake air flows past the temperature sensor (before heater), the heater, and then the temperature sensor (after heater) of the silicon chip sensor in the by-pass duct. As the intake air is warmed up when it is exposed to the heater, the temperature of the intake air as it flows past the temperature sensor (after heater) is higher than when it flows past the temperature sensor (before heater). The difference in temperature of the intake air at each temperature sensor varies depending on the velocity of the intake air that flows past the silicon chip sensor. The temperature sensor bridge circuit detects the difference in temperature and the control circuit converts it into a pulse signal and outputs it to the ECM. When the temperature detected by the temperature sensor (before heater) is higher than that detected by the temperature sensor (after heater), backflow of the intake air is detected.

The ECM calculates the intake air volume based on the pulse signal received from the mass air flow meter.

The heater control bridge circuit has a temperature sensor and power transistor, and maintains the heater temperature at a specific temperature.

A01VITBE04
Text in Illustration
*1 Mass Air Flow Meter - -
*a Silicon Chip Sensor *b By-pass Duct
*c Heater *d Heater Thermistor
*e Intake Air *f Temperature Sensor (After Heater)
*g Temperature Sensor (Before Heater) *h Intake Air Thermistor 1
*i Intake Air Thermistor 2 *j Temperature Sensor (Before Heater) 1
*k Temperature Sensor (After Heater) 2 *l Temperature Sensor (After Heater) 1
*m Temperature Sensor (Before Heater) 2 *n Control Circuit
*o Heater Control Bridge Circuit *p Temperature Sensor Bridge Circuit
*q Air Flow - -
P0100
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
3 seconds after engine is started Mass air flow meter signal frequency is less than 850 Hz with the engine speed at 400 rpm or more for 3 seconds (2 trip detection logic).

  • Open or short in mass air flow meter circuit

  • Mass air flow meter

  • ECM
Related Data List
DTC No. Data List
P0100 MAF

Tech Tips


  • If DTC P0100 is stored, the following symptoms may appear (as the ECM mistakenly determines that there is less air than the actual intake air amount, EGR is decreased according to the target EGR):


    • Combustion noise worsens

WIRING DIAGRAM

A01VJQAE02

CAUTION / NOTICE / HINT

Note

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

Tech Tips


  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing a new ECM, perform all of the initialization and registration procedures for the "Learning Values Write" function by following the instructions shown on the GTS display.

  • 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 TERMINAL VOLTAGE (VC VOLTAGE)

    A01VG81E01
    Text in Illustration
    *a

    Front view of wire harness connector

    (to Mass Air Flow Meter)

    1. Disconnect the mass air flow meter connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A102-3 (VCC) - Body ground Ignition switch ON 4.8 to 5.2 V
      A102-1 (FG) - A102-2 (E2G) Ignition switch ON 4.8 to 5.2 V

    NG

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) Click here

    OK

  2. REPLACE MASS AIR FLOW METER


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


    NEXT

  3. CHECK WHETHER DTC OUTPUT RECURS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Start the engine and wait for 3 seconds or more.

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

    7. Read the DTCs.

      Result
      Result Proceed to
      DTC is not output A
      P0100 is output B

    A

    END

    B

    REPLACE ECM Click here

  4. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)


    1. Disconnect the A102 mass air flow meter connector.

    2. Disconnect the B104 ECM connector (for LHD).

    3. Disconnect the B103 ECM connector (for RHD).

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      A102-3 (VCC) - B104-99 (VCVG) Always Below 1 Ω
      A102-1 (FG) - B104-97 (VG) Always Below 1 Ω
      A102-2 (E2G) - B104-100 (EVG) Always Below 1 Ω
      A102-3 (VCC) or B104-99 (VCVG) - Body ground Always 10 kΩ or higher
      A102-1 (FG) or B104-97 (VG) - Body ground Always 10 kΩ or higher
      A102-2 (E2G) or B104-100 (EVG) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      A102-3 (VCC) - B103-99 (VCVG) Always Below 1 Ω
      A102-1 (FG) - B103-97 (VG) Always Below 1 Ω
      A102-2 (E2G) - B103-100 (EVG) Always Below 1 Ω
      A102-3 (VCC) or B103-99 (VCVG) - Body ground Always 10 kΩ or higher
      A102-1 (FG) or B103-97 (VG) - Body ground Always 10 kΩ or higher
      A102-2 (E2G) or B103-100 (EVG) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  5. CHECK WHETHER DTC OUTPUT RECURS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Start the engine and wait for 3 seconds or more.

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

    7. Read the DTCs.

      Result
      Result Proceed to
      DTC is not output A
      P0100 is output B

    OK

    END

    NG

  6. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  7. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Start the engine and wait for 3 seconds or more.

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

    7. Confirm that the DTC is not output.


    NEXT

    END

  8. REPAIR OR REPLACE HARNESS OR CONNECTOR


    NEXT

  9. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Start the engine and wait for 3 seconds or more.

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

    7. Confirm that the DTC is not output.


    NEXT

    END