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Home >> Lexus >> 2012 >> HS 250h >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System (Diagnostic Codes (P0010-P2419)) >> SFI System >> DTC P0102, P0103: Mass or Volume Air Flow Circuit Low Input; Mass or Volume Air Flow Circuit High Input >> Procedure
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DTC P0102, P0103: Mass or Volume Air Flow Circuit Low Input; Mass or Volume Air Flow Circuit High Input: Procedure

  1. READ DTC OUTPUT 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.
    5. Read the DTCs.

      Result

      Result Proceed to
      DTC P0102 is output A
      DTC P0103 is output B

    B → See step   5 

    A: Go to next step 

  2. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY (POWER SOURCE VOLTAGE) 
    Fig 1: Identifying Mass Air Flow Meter Sub-Assembly Connector (Power Source Voltage)
    GTY274508Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the mass air flow meter sub-assembly connector.
    2. Turn the power switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      C1-3 (+B) - Body ground Power switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Mass Air Flow Meter Sub-assembly)
    4. Reconnect the mass air flow meter sub-assembly connector.

    NG → See step   7 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU) 
    1. Disconnect the mass air flow meter sub-assembly connector.
    2. Disconnect the hybrid vehicle control ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      C1-5 (VG) - C28-74 (VG) Always Below 1 Ω
      C1-4 (E2G) - C28-73 (EVG) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      C1-5 (VG) or C28-74 (VG) - Body ground Always 10 kΩ or higher
    4. Reconnect the mass air flow meter sub-assembly connector.
    5. Reconnect the hybrid vehicle control ECU connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY 
    1. Perform On-vehicle inspection. Refer to ON-VEHICLE INSPECTION .
    2. Perform Inspection. Refer to INSPECTION .
    3. Inspect the function of the mass air flow meter sub-assembly.
      1. Connect the Techstream to the DLC3.
      2. Turn the power switch on (IG).
      3. Turn the Techstream on.
      4. Put the engine in inspection mode (maintenance mode). Refer to INSPECTION MODE PROCEDURE .
      5. Start the engine.
      6. Enter the following menus: Powertrain/Engine and ECT/Data List/Primary/MAF.
      7. Check that the reading of MAF value changes when the engine is raced.

        OK

        The reading changes.

    NG → See step   13 

    OK → See step   11 

  5. CHECK HARNESS AND CONNECTOR (SENSOR GROUND) 
    1. Disconnect the mass air flow meter sub-assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      C1-4 (E2G) - Body ground Always Below 1 Ω
    3. Reconnect the mass air flow meter sub-assembly connector.

    NG → See step   6 

    OK → See step   13 

  6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU) 
    1. Disconnect the mass air flow meter sub-assembly connector.
    2. Disconnect the hybrid vehicle control ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      C1-4 (E2G) - C28-73 (EVG) Always Below 1 Ω
    4. Reconnect the mass air flow meter sub-assembly connector.
    5. Reconnect the hybrid vehicle control ECU connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   11 

  7. INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN RELAY) 
    1. Inspect the No. 1 integration relay. Refer to INSPECTION .

    NG → See step   12 

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - MASS AIR FLOW METER SUB-ASSEMBLY) 
    1. Remove the No. 1 integration relay from the engine room relay block.
    2. Disconnect the No. 1 integration relay connector.
    3. Disconnect the mass air flow meter sub-assembly connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      1B-4 - C1-3 (+B) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      1B-4 or C1-3 (+B) - Body ground Always 10 kΩ or higher
    5. Reconnect the mass air flow meter sub-assembly connector.
    6. Reconnect the No. 1 integration relay connector.
    7. Reinstall the No. 1 integration relay.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  9. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - IGCT RELAY) See step   7 

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  10. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - BODY GROUND) See step   8 

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - EFI MAIN RELAY) 

  11. REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  REMOVAL 
  12. REPLACE NO. 1 INTEGRATION RELAY. Refer to  REMOVAL 
  13. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY. Refer to  REMOVAL 
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