SFI SYSTEM, Diagnostic DTC:P0102

DTC Code DTC Name
P0102 Mass or Volume Air Flow Sensor "A" Circuit Low

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0102 Mass or Volume Air Flow Sensor "A" Circuit Low

Enable Criteria


  • Engine running

Malfunction Criteria


  • Voltage at ECU less than 0.503 V for time 1.5 seconds or more

Diagnostic Mask


  • The MIL will be illuminated if the faults are present for 2 consecutive trips

Monitor


  • Continuous

Potential failure modes


  • MAF sensor circuit open

  • MAF sensor circuit short to ground

  • Open or short in mass air flow meter circuit

  • Mass air flow meter

  • ECM

 Comes on DTC stored

MONITOR DESCRIPTION

The Mass Air Flow (MAF) sensor is incorporated into the air box, and measures both intake air flow rate and Intake Air Temperature (IAT). The MAF sensor uses a hot wire exposed to the airflow, which is maintained at a constant temperature by a constant current flow. This is achieved within the sensor unit by varying the voltage applied to the hot wire. This voltage is the output signal from the MAF sensor.

WIRING DIAGRAM

B0045SWE02

CAUTION / NOTICE / HINT

Note

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

Tech Tips

Read freeze frame data using the GTS. 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. READ OUTPUT DTC (DTC P0102)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Trouble Codes.

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P0102 is output A
      DTC P0102 and other DTCs are output B

    B

    GO TO DTC CHART Click here

    A

  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER)


    1. B0047Y0C05
      *a

      Front view of wire harness connector

      (to Mass Air Flow Meter)

      Disconnect the mass air flow meter connector.

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A117-1 (+B) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT EFI MAIN RELAY Click here

    OK

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


    1. Disconnect the A117 mass air flow meter connector.

    2. Disconnect the B142 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A117-3 (VG) - B142-43 (VG) Always Below 1 Ω
      A117-5 (E2G) - 142-21 (E2G) Always Below 1 Ω
      A117-3 (VG) or B142-43 (VG) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT MASS AIR FLOW METER


    1. Inspect the mass air flow meter, referring to the On-vehicle Inspection for mass air flow meter.

      Click here

    2. Inspect the mass air flow meter, referring to the Inspection for mass air flow meter.

      Click here

    3. Inspect the function of the mass air flow meter.


      1. Connect the GTS to the DLC3.

      2. Turn the engine switch on (IG).

      3. Turn the GTS on.

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

      5. Start the engine.

      6. Check that the MAF value changes when the engine is raced.

        OK
        The reading changes.

        Tech Tips

        Perform "Inspection After Repair" after replacing the mass air flow meter.

        Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPLACE MASS AIR FLOW METER Click here

  5. INSPECT EFI MAIN RELAY


    1. Inspect the EFI MAIN relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EFI MAIN RELAY

    OK

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


    1. Remove the EFI MAIN relay from the No. 2 engine room relay block assembly.

    2. Disconnect the A117 mass air flow meter connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (EFI MAIN relay holder) - A117-1 (+B) Always Below 1 Ω
      3 (EFI MAIN relay holder) or A117-1 (+B) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    CHECK ECM POWER SOURCE CIRCUIT Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR