ECD SYSTEM, Diagnostic DTC:P0100, P0102, P0103

DTC Code DTC Name
P0100 Mass or Volume Air Flow Circuit
P0102 Mass or Volume Air Flow Circuit Low Input
P0103 Mass or Volume Air Flow Circuit High Input

DESCRIPTION

The mass air flow meter sub-assembly uses a platinum hot wire. The hot wire mass air flow meter sub-assembly consists of a platinum hot wire, thermistor and a control circuit installed in a plastic housing. The hot wire mass air flow meter sub-assembly works on the principle that the hot wire and thermistor located in the intake air bypass of the housing detect any changes in the intake air temperature.

The hot wire is maintained at the set temperature by controlling current flow through the hot wire. This current flow is then measured as the output voltage of the mass air flow meter sub-assembly.

The circuit is constructed so that the platinum hot wire and thermistor provide a bridge circuit with the power transistor controlled so that the potential of A and B remains equal to maintain the set temperature.

A01CI1AE04
DTC No. DTC Detection Condition Trouble Area
P0100 Open or short in mass air flow meter sub-assembly circuit for more than 3 seconds with engine speed at 4000 rpm or less

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

  • Mass air flow meter sub-assembly

  • ECM
P0102 Open in mass air flow meter sub-assembly circuit for more than 3 seconds with engine speed at 4000 rpm or less

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

  • Mass air flow meter sub-assembly

  • ECM
P0103 Short in mass air flow meter sub-assembly circuit for more than 3 seconds with engine speed at 4000 rpm or less

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

  • Mass air flow meter sub-assembly

  • ECM

Tech Tips

When DTC P0100, P0102 or P0103 is detected, check the mass air flow ratio by selecting the following menus using the intelligent tester: Powertrain / Engine and ECT / Data List / MAF.

Air Flow Value (gm/sec) Malfunction
Approximately 0.0

  • Open in mass air flow meter sub-assembly power source circuit

  • Open
160.1 or more Open in EVG circuit

WIRING DIAGRAM

A01CHNAE01

INSPECTION PROCEDURE

Tech Tips

Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, as well as other data recorded at the time of a malfunction.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (MAF)


    1. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

    2. Connect the intelligent tester to the DLC3.

    3. Start the engine.

    4. Turn the tester on.

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

    6. Read the value.

      Result
      Air Flow Rate (gm/sec) Proceed to
      0.0 A
      160.1 or more B
      Between 1.6 and 160.0* C

      Tech Tips

      *: The value should change when the throttle valve is opened or closed.


    B

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

    C

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  2. CHECK MASS AIR FLOW METER SUB-ASSEMBLY (POWER SOURCE)


    1. A01CGWHE19
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Mass Air Flow Meter Sub-assembly)

      Disconnect the mass air flow meter sub-assembly 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
      A20-1 (+B) - Body ground Ignition switch ON 11 to 14 V

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


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ENG-3 RELAY)

    OK

  3. INSPECT ECM (VG VOLTAGE)


    1. A01CGXCE85
      Text in Illustration
      *1

      Component with harness connected

      (ECM)

      Start the engine.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E23-24 (VG) - E23-32 (EVG) Engine is idling 1.5 to 1.9 V
      E23-24 (VG) - E23-32 (EVG) Engine speed at 3000 rpm 3.0 to 4.0 V

      Tech Tips

      The A/C switch should be turned off.


    NG

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

    OK

    REPLACE ECM Click here

  4. 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 (Check for Open)
      Tester Connection Condition Specified Condition
      A20-3 (VG) - E23-24 (VG) Always Below 1 Ω
      A20-2 (E2G) - E23-32 (EVG) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A20-3 (VG) or E23-24 (VG) - Body ground Always 10 kΩ or higher

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

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

    OK

    REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Click here