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Home >> Toyota >> 2010 >> Prius Base >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control (SFI) System (Diagnostic Codes (P0010-P0171)) (Except PHV) >> SFI System >> DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: Mass or Volume Air Flow Circuit High Input >> Procedure
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DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: 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 D5 Connector
    GTY226243Courtesy 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
      D5-3 (+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 → REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI MAIN RELAY - MASS AIR FLOW METER SUB-ASSEMBLY) 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 
    Fig 2: Identifying D5 And D28 Connector
    GTY232164Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the mass air flow meter sub-assembly 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
      D5-5 (VG) - D28-94 (VG) Always Below 1 Ω
      D5-4 (E2G) - D28-117 (E2G)

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      D5-5 (VG) or D28-94 (VG) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Mass Air Flow Meter Sub-assembly)      		 *2 Front view of wire harness connector
      (to ECM)
    4. Reconnect the mass air flow meter sub-assembly connector.
    5. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 

    OK: Go to next step 

  4. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY 
    Fig 3: Identifying Mass Air Flow Meter Sub-Assembly
    GTY232727Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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. Remove the mass air flow meter sub-assembly with the connector connected.
      2. Connect the Techstream to the DLC3.
      3. Turn the power switch on (IG).
      4. Turn the Techstream on.
      5. Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.
      6. Blow air to the mass air flow meter sub-assembly and check that the intake air amount reading changes.

      OK

      The reading changes.

    NG → See step   7 

    OK → See step   8 

  5. CHECK HARNESS AND CONNECTOR (SENSOR GROUND) 
    Fig 4: Identifying D5 Connector
    GTY226244Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the mass air flow meter meter sub-assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      D5-4 (E2G) - Body ground Always Below 1 Ω
      TEXT IN ILLUSTRATION

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

    NG → See step   6 

    OK → See step   7 

  6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 
    1. Disconnect the mass air flow meter sub-assembly connector.
      Fig 5: Identifying D8 And D28 Connectors
      GTY213396Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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
      D5-4 (E2G) - D28-117 (E2G) Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Mass Air Flow Meter Sub-assembly)      		 *2 Front view of wire harness connector
      (to ECM)
    4. Reconnect the mass air flow meter sub-assembly connector.
    5. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 

    OK → See step   8 

  7. REPLACE MASS AIR FLOW METER SUB-ASSEMBLY. Refer to  REMOVAL 
  8. REPLACE ECM. Refer to  REMOVAL 
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