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Home >> Subaru >> 2014 >> BRZ Limited, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (1 Of 4) >> DTC P0107 Manifold Absolute Pressure/Barometric Pressure Circuit Low Input; DTC P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input >> Description Of Functions >> Inspection steps
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Inspection steps

NOTE: Read the freeze frame data using the SSM3. A part of the engine running conditions under which the engine trouble occurred is recorded in the freeze frame data, which is useful for troubleshooting.
  1. Reading SSM3 data
    1. Connect the SSM3 to the DLC3.
    2. Turn the ignition switch to ON with engine stopped.
    3. Turn on the SSM3.
    4. Select the following menu items using the SSM3: [BRZ Check] / [Each System Check] / [Engine Control System] / [Current Data Display & Save] / [Mani. Absolute Pressure]
    5. Read [Mani. Absolute Pressure].

      Criteria: Indicates a value almost equal to the actual barometric pressure.

      MANIFOLD ABSOLUTE PRESSURE REFERENCE

      Inspection conditions [Mani. Absolute Pressure]
      IG ON, engine stop 80 to 110 kPa
      NOTE: Normal barometric pressure is 101 kPa {758 mmHg}. As altitude increases 100 m {328 ft}, the atmospheric pressure decreases 1 kPa. This rate of change depends on the weather.
      RESULT

      Result Go to
      Malfunction A
      Normal B

      B: Inspection for problems that do not normally occur (Refer to CHECK PROBLEMS THAT DO NOT CONSTANTLY OCCUR )

      A: Go to Next Step

  2. Check wiring harness and connector (air pressure sensor assembly power supply voltage check)
    NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .
    1. Disconnect the connector for air pressure sensor assembly.
    2. Measure the voltage between the terminals.
      VOLTAGE

      Inspection terminals Inspection conditions Standard value
      C18-3 (VC) - C18-1 (E2) IG ON 4.5 to 5.5 V
      C18-2 (PIM) - C18-1 (E2) IG ON 4.0 to 5.0 V
      Fig 1: Identifying Air Pressure Sensor Assembly Connector Terminals
      G08553724Courtesy of SUBARU OF AMERICA, INC.

      NG: Go to Step  6

      OK: Go to Next Step

  3. Replacement of air pressure sensor assembly
    1. Replace the air pressure sensor assembly. (Refer to VACUUM SENSOR assembly (FA20) )

      Next

  4. Clear DTC
    1. Connect the SSM3 to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn on the SSM3.
    4. Follow the SSM3 on-screen instructions to clear the DTCs. (Refer to CHECKING/CLEARING DTC )

      Next

  5. Perform test drive for operation check
    1. Perform test drive. (Refer to "TEST DRIVE " under "Description of functions")
    2. Connect the SSM3 to the DLC3.
    3. Turn the ignition switch to ON.
    4. Turn on the SSM3.
    5. Follow the SSM3 on-screen instructions to check the DTCs. (Refer to CHECKING/CLEARING DTC )
      RESULT

      Result Go to
      P0107 or P0108 is output. A
      No DTC is output B

      B: Complete

      A: Replacement of the engine control computer (Refer to REMOVAL )

  6. Check wiring harness and connector (air pressure sensor assembly - engine control computer)
    NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .
    1. Disconnect the connector for air pressure sensor assembly.
    2. Disconnect the connector for the engine control computer.
    3. Measure the resistance between the terminals. (Refer to ECM TERMINAL ARRANGEMENT for the terminal arrangement)
      RESISTANCE (OPEN CIRCUIT CHECK)

      Inspection terminals Inspection conditions Standard value
      A36-19 (VC) - C18-3 (VC) Always Less than 1 Ω
      A34-20 (PIM) - C18-2 (PIM) Always Less than 1 Ω
      A36-29 (E1) - C18-1 (E2) Always Less than 1 Ω
      RESISTANCE (SHORT CIRCUIT CHECK)

      Inspection terminals Inspection conditions Standard value
      A36-19 (VC) and C18-3 (VC) - other terminals and chassis ground Always 10 k Ωor more
      A34-20 (PIM) and C18-2 (PIM) - other terminals and chassis ground Always 10 k Ωor more
      A36-29 (E1) and C18-1 (E2) - other terminals and chassis ground Always 10 k Ωor more

      NG: Repair or replacement of wiring harness or connector

      OK: Replacement of the engine control computer (Refer to REMOVAL )

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