SFI 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 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 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, changing their resistance. To maintain a constant current value, the ECM varies the voltage applied to these components in the mass air flow meter. The voltage level is proportional to the air flow through the sensor, and the ECM uses it to calculate the intake air volume.

The circuit is constructed so that the platinum hot wire and the temperature sensor provide a bridge circuit, and the power transistor is controlled so that the potentials of A and B remain equal to maintain the predetermined temperature.

Tech Tips

When any of these DTCs are set, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is calculated by the ECM, according to the engine RPM and throttle valve position. Fail-safe mode continues until a pass condition is detected.

A017C6CE03
DTC No. DTC Detection Condition Trouble Area
P0100 Open or short in mass air flow meter circuit for 3 seconds (1 trip detection logic)

  • Open or short in mass air flow meter circuit

  • Mass air flow meter

  • ECM
P0102 Open in mass air flow meter circuit for 3 seconds (1 trip detection logic)

  • Open in mass air flow meter circuit

  • Short in ground circuit

  • Mass air flow meter

  • ECM
P0103 Short in mass air flow meter circuit for 3 seconds (1 trip detection logic)

  • Short in mass air flow meter circuit (+B circuit)

  • Mass air flow meter

  • ECM

Tech Tips

When any of these DTCs are set, check the air-flow rate by selecting the following menu items on an intelligent tester: Powertrain / Engine and ECT / Data List / MAF.

Mass Air Flow Rate (gm/s) Malfunction
Approximately 0.0

  • Open in mass air flow meter power source circuit

  • Open or short in VG circuit
271.0 or more Open in EVG circuit

WIRING DIAGRAM

A017BOHE11

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 running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (MASS AIR FLOW RATE)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine.

    3. Turn the tester on.

    4. Select the following menu items: Powertrain / Engine and ECT / Data List / MAF.

    5. Read the values displayed on the tester.

      Result
      Mass Air Flow Rate (gm/s) Proceed to
      0.0 A
      271.0 or more B
      Between 1.0 and 270.0 (*1) C

      *1: The value must be changed when the throttle valve is open or closed.


    B

    INSPECT ECM (SENSOR GROUND) Click here

    C

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  2. INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)


    1. A017F6ZE03

      Disconnect the mass air flow meter connector.

    2. Turn the ignition switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      B10-3 (+B) - Body ground Ignition switch on (IG) 9 to 14 V

    4. Reconnect the mass air flow meter connector.


    NG

    INSPECT FUSE (EFI NO. 3 FUSE) Click here

    OK

  3. INSPECT ECM (VG VOLTAGE)


    1. A017BQGE13

      Start the engine.

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

      Tech Tips

      The transmission gear selector lever should be in the P or N position and the air conditioning switch should be turned off.

      Standard voltage
      Tester Connection Condition Specified Condition
      B1-30 (VG) - B1-29 (E2G) Engine idling 0.5 to 3.0 V

    NG

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

    OK

    REPLACE ECM Click here

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


    1. A017CUDE04

      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
      B10-5 (VG) - B1-30 (VG) Always Below 1 Ω
      B10-4 (E2G) - B1-29 (E2G) Always Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      B10-5 (VG) or B1-30 (VG) - Body ground Always 10 kΩ or higher

    4. Reconnect the mass air flow meter connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MASS AIR FLOW METER Click here

  5. INSPECT FUSE (EFI NO. 3 FUSE)


    1. A017ENJE02

      Remove the EFI No. 3 fuse from the engine room relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      EFI No. 3 fuse Always Below 1 Ω

    3. Reinstall the EFI No. 3 fuse.


    NG

    REPLACE EFI NO. 3 FUSE

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - EFI NO. 3 FUSE)

  6. INSPECT ECM (SENSOR GROUND)


    1. A017BQGE14

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

      Standard resistance
      Tester Connection Condition Specified Condition
      B1-29 (E2G) - Body ground Always Below 1 Ω

    NG

    REPLACE ECM Click here

    OK

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


    1. A017CUDE04

      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
      B10-5 (VG) - B1-30 (VG) Always Below 1 Ω
      B10-4 (E2G) - B1-29 (E2G) Always Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      B10-5 (VG) or B1-30 (VG) - Body ground Always 10 kΩ or higher
      B10-4 (E2G) or B1-29 (E2G) - Body ground Always 10 kΩ or higher

    4. Reconnect the mass air flow meter connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MASS AIR FLOW METER Click here