СИСТЕМА ECD, Diagnostic DTC:P0100

DTC Code DTC Name
P0100 Mass Air Flow Circuit

DESCRIPTION

The mass air flow meter assembly consists of a platinum hot wire, temperature sensor and control circuit installed in a plastic housing. The temperature sensor (located in the intake air by-pass of the housing) detects the intake air temperature.

There is little variation in the output from the mass air flow meter assembly, as it is hardly affected by the resistance of the wire harness.

The internal circuit of the mass air flow meter assembly contains a hot wire and cold wire. A voltage is output through a bridge circuit (refer to the illustration) indicating the cooling of the hot wire according to the intake air amount. This voltage is then converted into a periodic signal by the periodic signal conversion circuit and output to the ECM. The frequency varies between approximately 1945 and 8500 Hz depending on the air flow rate. The ECM calculates the mass air flow rate based on this frequency.

A01IRR1E01
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 (1 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

A01IP61E03

INSPECTION PROCEDURE

Note


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

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

Tech Tips

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. INSPECT MASS AIR FLOW METER (POWER SOURCE CIRCUIT)

    A01INKHE01
    Text in Illustration
    *a

    Front view of wire harness connector

    (to Mass Air Flow Meter)

    1. Disconnect the mass air flow meter connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C3-3 (+B) - Body ground Ignition switch ON 11 to 14 V

    3. Reconnect the mass air flow meter connector.


    NG

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - EFI MAIN RELAY) Click here

    OK

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


    1. A01IQ4WE21
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Mass Air Flow Meter)
      *b

      Front view of wire harness connector

      (to ECM)

      Disconnect the mass air flow meter connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      C3-1 (VG) - C69-65 (VG) Always Below 1 Ω
      C3-2 (E2G) - C69-64 (EVG) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C3-1 (VG) or C69-65 (VG) - Body ground Always 10 kΩ or higher

    4. Reconnect the mass air flow meter connector.

    5. Reconnect the ECM connector.


    OK

    REPLACE MASS AIR FLOW METER Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

  3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - EFI MAIN RELAY)


    1. A01INMZE03
      Text in Illustration
      *1 Engine Room No. 1 Relay Block
      *2 EFI MAIN relay
      *a

      Front view of wire harness connector

      (to Mass Air Flow Meter)

      Disconnect the mass air flow meter connector.

    2. Remove the EFI MAIN relay from the engine room No. 1 relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C3-3 (+B) - 3 (EFI MAIN relay holder) Always Below 1 Ω
      C3-3 (+B) or 3 (EFI MAIN relay holder) - Body ground Always 10 kΩ or higher

    4. Reconnect the mass air flow meter connector.

    5. Reinstall the EFI MAIN relay.


    OK

    CHECK ECM POWER SOURCE CIRCUIT Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  5. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  6. REPLACE MASS AIR FLOW METER


    1. Replace the mass air flow meter Click here.


    NEXT

  7. CHECK WHETHER DTC OUTPUT RECURS


    1. Connect the intelligent tester to the DLC3.

    2. Clear the DTCs Click here.

    3. After engine is started for 3 seconds.

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

    5. Read the DTCs.

      Result
      Result Proceed to
      P0100 is output A
      No DTC is output B

    B

    END

    A

  8. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  9. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the intelligent tester to the DLC3.

    2. Clear the DTCs Click here.

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

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

    5. Confirm that the DTC is not output again.


    NEXT

    END