СИСТЕМА ECD, Diagnostic DTC:P0102, P0103

DTC Code DTC Name
P0102 Mass Air Flow Circuit Low
P0103 Mass Air Flow Circuit High

DESCRIPTION

The Mass Air Flow (MAF) meter consists of a platinum hot wire, a temperature sensor and a control circuit installed in a plastic housing. The temperature sensor (located in the intake air by-pass of the housing) detect the intake air temperature.

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

The internal circuit of the mass air flow meter 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 250 to 11000 Hz depending on the air flow rate. The ECM calculates the mass air flow rate based on this frequency.

A012H11E04
DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0102 Mass Air Flow Circuit Low

Generated pulse period is 50 μsec. or less (MAF value is extremely high).

(1 trip detection logic)

  • Open or short in Mass Air Flow (MAF) meter circuit

  • Mass air flow meter

  • ECM

 Comes on DTC stored
P0103 Mass Air Flow Circuit High

Generated pulse period is 2100 μsec. or more (MAF value is extremely low).

(1 trip detection logic)

  • Open or short in Mass Air Flow (MAF) meter circuit

  • Mass air flow meter

  • ECM

 Comes on DTC stored
Table 1. DTC Detection Drive Pattern
DTC No. DTC Detection Drive Pattern
P0102 Engine speed between 750 to 2500 rpm
P0103
Table 2. Related Data List
DTC No. Data List
P0102 MAF
P0103
Tip:

  • If DTC P0102 is stored, the following symptoms may appear (as the ECU mistakenly determines that there is less air than the actual intake air amount, EGR is decreased to match the target EGR):

    • Combustion noise increases

  • If DTC P0103 is stored, the following symptoms may appear (as the ECU mistakenly determines that there is more air than the actual intake air amount, EGR is increased to match the target EGR):

    • Misfire

    • White smoke

    • Black smoke

WIRING DIAGRAM

A012II8E01

CAUTION / NOTICE / HINT

Note:

  • When replacing the ECM, perform ECM Initialization and Registration.

    Click here Нажмите здесь

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

Tip:

  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing a new ECM, perform all of the initialization and registration procedures for the "Learning Values Write" function by following the instructions shown on the GTS display.

  • Read freeze frame data using the GTS. 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. CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER)

    1. Disconnect the mass air flow meter connector.

      A012FU9C03
      *a

      Front view of wire harness connector

      (to Mass Air Flow Meter)

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      B2-3 (+B) - Body ground Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG
    NG Нажмите здесь

    OK

  2. 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
      Tester Connection Condition Specified Condition
      B2-1 (VG) - A101-11 (VG) Always Below 1 Ω
      B2-2 (E2G) - A101-12 (EVG) Always Below 1 Ω
      B2-1 (VG) or A101-11 (VG) - Body ground Always 10 kΩ or higher
      B2-2 (E2G) or A101-12 (EVG) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG
    NG Нажмите здесь

    OK

  3. REPLACE MASS AIR FLOW METER

    1. Replace the mass air flow meter.

      Click hereНажмите здесь

      Result
      Proceed to
      NEXT
    NEXT

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P0102 OR P0103)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    4. Start the engine and depress the accelerator pedal several times to vary the engine speed to between 750 and 2500 rpm.

    5. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    6. Read the DTCs.

      Powertrain > Engine and ECT > Trouble Codes
      Result
      ResultProceed to
      DTC P0102 or P0103 is outputA
      DTC is not outputB
    B

    END

    A

  5. REPLACE ECM

    1. Replace the ECM.

      Click hereНажмите здесь

      Result
      Proceed to
      NEXT
    NEXT

  6. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    4. Start the engine and depress the accelerator pedal several times to the engine speed between 750 to 2500 rpm.

    5. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    6. Confirm that the DTC is not output again.

      Powertrain > Engine and ECT > Trouble Codes
      Result
      Proceed to
      NEXT
    NEXT

    END

  7. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT
    NEXT Нажмите здесь

    GO TO STEP 6

  8. REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN RELAY - MASS AIR FLOW METER)

    Result
    Proceed to
    NEXT
    NEXT Нажмите здесь

    GO TO STEP 6