ECD SYSTEM (w/o EGR Cooler), 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 (MAF) meter measures the amount of air flowing through the throttle valve. The ECM uses this information to determine the fuel injection time and provide a proper air-fuel ratio. Inside the MAF meter, there is a heated platinum wire exposed to the flow of intake air.

By applying a specific current to the wire, the ECM heats this wire to a given temperature. The flow of incoming air cools the wire and an internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the voltage applied to these components in the MAF meter. The voltage level is proportional to the air flow through the sensor. The ECM interprets this voltage as the intake air amount.

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

A01DVC7E02
DTC No. DTC Detection Condition Trouble Area
P0100

When MAF meter circuit has open or short for more than 3 seconds under 2,000 rpm engine speed

(1 trip detection logic)

  • Open or short in MAF meter circuit

  • MAF meter

  • ECM
P0102

When MAF meter circuit has open for more than 3 seconds under 2,000 rpm engine speed

(1 trip detection logic)

  • Open or short in MAF meter circuit

  • MAF meter

  • ECM
P0103

When MAF meter circuit has short for more than 3 seconds under 2,000 rpm engine speed

(1 trip detection logic)

  • Open or short in MAF meter circuit

  • MAF meter

  • ECM

Tech Tips

When DTC P0100, P0102 or P0103 is detected, check the air-flow ratio by entering the following menus on the intelligent tester: Powertrain / Engine / Data List / MAF.

Air Flow Rate (gm/s) Malfunction
Approximately 0.0

  • Open in MAF meter power source circuit

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

WIRING DIAGRAM

A01DWDAE02

INSPECTION PROCEDURE

Tech Tips

Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, and other data from the time the malfunction occurred.

Note

If the ECM is replaced, the new ECM needs initialization Click here.

PROCEDURE


  1. READ DATA LIST (MASS AIR FLOW RATE)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and turn the intelligent tester ON.

    3. Enter the following menus: Powertrain / Engine / Data List / MAF.

    4. Read the values.

      Result
      Air Flow Rate (gm/s) Proceed to
      Approximately 0.0 A
      167.5 or more B
      Between 1 and 167.4* C

      Tech Tips

      *: The value must changed when the throttle valve is opened or closed.


    B

    CHECK ECM (SENSOR GROUND) Click here

    C

    CHECK FOR INTERMITTENT PROBLEMS

    A

  2. CHECK MASS AIR FLOW METER (POWER SOURCE)

    A01E1OJE05

    1. Disconnect the A4 MAF meter connector.

    2. Turn the ignition switch ON.

    3. Measure the voltage of the wire harness side connector.

      Standard voltage
      Tester Connection Specified Condition
      A4-1 (+B) - Body ground 9 to 14 V

    NG

    CHECK WIRE HARNESS (MASS AIR FLOW METER - INTEGRATION RELAY (MAIN RELAY)) Click here

    OK

  3. CHECK ECM (VG VOLTAGE)

    A01DW5TE43

    1. Start the engine.

    2. Measure the voltage of the ECM connector.

      Standard voltage
      Tester Connection Condition Specified Condition
      E7-24 (VG) - E7-32 (EVG) Engine idling 0.5 to 3.4 V

      Tech Tips

      The A/C switch should be turned OFF.


    OK

    REPLACE ECM

    NG

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

    A01DWNKE03

    1. Disconnect the A4 MAF meter connector.

    2. Disconnect the E7 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      A4-3 (VG) - E7-24 (VG) Below 1 Ω
      A4-2 (E2G) - E7-32 (EVG) Below 1 Ω
      A4-3 (VG) or E7-24 (VG) - Body ground 10 kΩ or higher
      A4-2 (E2G) or E7-32 (EVG) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE MASS AIR FLOW METER

  5. CHECK WIRE HARNESS (MASS AIR FLOW METER - INTEGRATION RELAY (MAIN RELAY))

    A01E2GVE03

    1. Disconnect the A4 MAF meter connector.

    2. Remove the integration relay from the engine room junction block Click here.

    3. Disconnect the 1J integration relay connector.

    4. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      A4-1 (+B) - 1J-5 Below 1 Ω
      A4-1 (+B) or 1J-5 - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    INSPECT ECM POWER SOURCE CIRCUIT

  6. CHECK ECM (SENSOR GROUND)

    A01DW5TE44

    1. Measure the resistance of the ECM connector.

      Standard resistance
      Tester Connection Specified Condition
      E7-32 (EVG) - Body ground Below 1 Ω

    NG

    REPLACE ECM

    OK

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

    A01DWNKE03

    1. Disconnect the A4 MAF meter connector.

    2. Disconnect the E7 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      A4-3 (VG) - E7-24 (VG) Below 1 Ω
      A4-2 (E2G) - E7-32 (EVG) Below 1 Ω
      A4-3 (VG) or E7-24 (VG) - Body ground 10 kΩ or higher
      A4-2 (E2G) or E7-32 (EVG) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE MASS AIR FLOW METER