SFI SYSTEM, Diagnostic DTC:P0102, P0103

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

DESCRIPTION

The Mass Air Flow (MAF) 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 the appropriate air fuel ratio.

Inside the MAF meter, there is a heated platinum wire which is exposed to the flow of intake air.

The flow of incoming air cools both the wire and an internal thermistor, affecting their resistance. To maintain a constant temperature value of the hot wire, current is applied to these components in the MAF meter. The voltage level is proportional to the airflow 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 create 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.

A011APGE01
DTC No. DTC Detection Condition Trouble Area
P0102

Mass air flow meter voltage less than 0.2 V for 3 seconds

(1 trip detection logic)

  • Open or short in mass air flow meter circuit

  • Mass air flow meter

  • ECM
P0103

Mass air flow meter voltage more than 4.9 V for 3 seconds

(1 trip detection logic)

  • Open or short in mass air flow meter circuit

  • Mass air flow meter

  • ECM

Tech Tips

When any of these DTCs are set, check the air-flow rate by entering the following menus: Powertrain / Engine and ECT / Data List / MAF.

Mass Air Flow Rate (gm/sec) 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 E2G circuit

WIRING DIAGRAM

A0119IME01

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following 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 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 P0102 OR P0103)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Allow the engine to idle for 1 minute or more.

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

    7. Read the DTCs.

      Result
      Result Proceed to
      DTC P0102, and/or P0103 are output A
      DTC is not output B

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

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

    Note


    • Do not start the engine.

    • Perform the inspection with the vehicle indoors and on a level surface.

    • Perform the inspection of the Mass air flow meter while it is installed to the air cleaner case (installed to the vehicle).

    • During the test, do not use an exhaust air duct on the exhaust tail pipe assembly.


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON (do not start the engine).

    3. Turn the tester on.

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

    5. Wait 30 seconds, and read the values on the tester.

      Result
      Result Proceed to
      0.0 gm/sec A
      More than 0.25 gm/sec B

    B

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SENSOR GROUND) Click here

    A

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

    A01185DE12
    Text in Illustration
    *1

    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
      B53-3 (+B) - Body ground Ignition switch ON 11 to 14 V

    4. Reconnect the mass air flow meter connector.


    NG

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

    OK

  4. INSPECT MASS AIR FLOW METER


    1. A011BCME02

      Remove the mass air flow meter with the wire harness connector connected.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the tester on.

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

    6. Check the MAF value when air is blown to the mass air flow meter, as shown in the illustration.

      OK
      The MAF value changes.

    7. Reinstall the mass air flow meter with the wire harness connector connected.


    NG

    REPLACE MASS AIR FLOW METER Click here

    OK

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


    1. 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
      B53-5 (VG) - B8-69 (VG) Always Below 1 Ω
      B53-4 (E2G) - B8-92 (E2G)
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B53-5 (VG) or B8-69 (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 ECM Click here

  6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY)


    1. Disconnect the mass air flow meter connector.

    2. Remove the integration relay.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B53-3 (+B) - 1E-2 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B53-3 (+B) or 1E-2 - Body ground Always 10 kΩ or higher

    4. Reconnect the mass air flow meter connector.

    5. Reinstall the integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPAIR OR REPLACE ECM POWER SOURCE CIRCUIT

  7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SENSOR GROUND)

    A01185DE11
    Text in Illustration
    *1

    Front view of wire harness connector

    (to Mass Air Flow Meter)

    1. Disconnect the mass air flow meter connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B53-4 (E2G) - Body ground Always Below 1 Ω

    3. Reconnect the mass air flow meter connector.


    NG

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

    OK

    REPLACE MASS AIR FLOW METER Click here

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


    1. 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
      B53-5 (VG) - B8-69 (VG) Always Below 1 Ω
      B53-4 (E2G) - B8-92 (E2G)
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B53-5 (VG) or B8-69 (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 ECM Click here