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Home >> Subaru >> 2015 >> BRZ Series.Blue, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Diagnostics (2 Of 3) >> DTC P050A Cold Start Idle Air Control System Performance; DTC P050B Cold Start Ignition Timing Abnormal >> Description of functions >> Inspection steps

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.
CAUTION: Check fuses of the circuits related to this system before performing the following inspection steps.
  1. Read 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 check the DTC. (Refer to CHECKING/CLEARING DTC )

      Result

      Result Go to
      P050A or P050B is displayed. A
      P050A or P050B and other DTCs are displayed. B
      NOTE: If any DTCs other than P050A or P050B are present, troubleshoot the DTCs first.

      B: To corresponding DTC chart (refer to DTC TABLE )

      A: Go to next step

  2. Reading by the SSM3 ([air/fuel learning value # 1] and [air/fuel correction value #1])
    NOTE: Calculate the total fuel correction amount, and check the characteristic deviations of the intake air flow meter sub-assembly.
    1. Connect the SSM3 to the DLC3.
    2. Start the engine.
    3. Turn on the SSM3.
    4. Select the following menu items using the SSM3. [Inspection of BRZ]/[Each System Check]/[Engine Control System]/[Current Data Display & Save]/[Long term fuel trim B1] and [Short term fuel trim B1]
    5. Read the value displayed on the SSM3 on idle.
    6. Add the values of [air/fuel learning value # 1] and [air/fuel correction value #1] to calculate the total fuel correction amount.

      Criteria: Sum of [Long term fuel trim B1] and [Short term fuel trim B1] are between -20 % and 20 %.

      NG: Go to Step  5.

      OK: Go to next step

  3. Throttle body check (throttle valve)
    1. Check that no deposit is adhered around the throttle valve, and check the condition of the throttle valve.

      Criteria: There is no deposit adhered around the throttle valve, and the valve operates smoothly.

      OK: Go to Step  14.

      NG: Go to Step 4.

  4. Repair or replacement of throttle body
    1. Repair or replace the throttle body. (refer to REMOVAL )

      Next: Go to Step  14.

  5. Inspection of the PCV hose
    1. Check the PCV hose for poor connections and damage.

      Criteria: The PCV valve and hose are connected properly and not damaged.

      NG: Go to Step  10.

      OK: Go to next step

  6. Intake system inspection
    1. Inspect the intake system. (refer to ON-VEHICLE INSPECTION )

      Criteria: There is no leakage in the intake system.

      NG: Go to Step  11.

      OK: Go to next step

  7. Air cleaner filter element sub-assembly check
    1. Visually check the air cleaner filter element for heavy contamination with mud and oil.

      Criteria: The air cleaner filter element is not heavily contaminated with mud and oil.

      NG: Go to Step  12.

      OK: Go to next step

  8. Perform the [system operation check mode] using the SSM3 ([camshaft timing oil control valve assembly operation]).
    1. Operate the VVT system in the [system operation check mode] and check that the VVT system operates without problem.
      1. By referring to the inspection steps of DTC P0011 (VVT system of the intake camshaft), perform the [system operation check mode]. (Refer to CHECKING/CLEARING DTC )
      2. By referring to the inspection steps of DTC P0014 (VVT system of the exhaust camshaft), perform the [system operation check mode]. (Refer to CHECKING/CLEARING DTC )

      NG: Go to Step  13.

      OK: Go to next step

  9. Reading by the SSM3 ((mass air flow) Refer to DTC P0191 FUEL RAIL PRESSURE SENSOR "A" CIRCUIT RANGE/PERFORMANCE; DTC P0192 FUEL RAIL PRESSURE SENSOR CIRCUIT LOW INPUT; DTC P0193 FUEL RAIL PRESSURE SENSOR CIRCUIT HIGH INPUT  )

    OK: Go to Step  14.

    NG: Go to Step  15.

  10. Repair or replacement of the PCV hose
    1. Repair or replace the PCV valve and hose.

      Next: Go to Step  14.

  11. Repair or replacement of intake system
    1. Repair or replace the intake system.

      Next: Go to Step  14.

  12. Replacement of air cleaner filter element sub-assembly
    1. Replace the air cleaner filter element sub-assembly.

      Next: Go to Step  14.

  13. VVT system check and repair
    1. Check and repair the VVT system.
      NOTE:
      • Refer to the inspection steps of DTC P0011 (VVT system of the intake camshaft). (Refer to CHECKING/CLEARING DTC )
      • Refer to the inspection steps of DTC P0041 (VVT system of the exhaust camshaft). (Refer to CHECKING/CLEARING DTC )

      NG: Go to Step 13.

      OK: Go to next step

  14. DTC recheck (DTC P050A or P050B)
    CAUTION: In order to perform this operation, the engine must be cold (at a temperature equivalent to the engine coolant temperature recorded in the freeze frame data).
    1. Connect the SSM3 to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn on the SSM3.
    4. Clear the DTC. (Refer to CURRENT DATA DISPLAY & SAVE/SYSTEM OPERATION CHECK MODE )
    5. Turn IG to OFF and wait for at least 30 seconds.
    6. According to the driving pattern described in test drive, drive the vehicle.
    7. Follow the SSM3 on-screen instructions to check the DTC. (Refer to CHECKING/CLEARING DTC )

      Result

      Result Go to
      A DTC is not displayed. A
      P050A or P050B is displayed. B

      B: Go to Step 15.

      A: Inspection for problems that do not normally occur (Refer to CHECKING/CLEARING DTC )

  15. Check wiring harness and connector (connection of intake air flow meter sub-assembly connector)
    1. Check the connection and terminal contact pressure of the connector and wiring harness between the intake air flow meter sub-assembly and the ECM. (refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM )
      NOTE: If abnormal, repair them.

      Next

  16. Read DTC
    CAUTION: In order to perform this operation, the engine must be cold (at a temperature equivalent to the engine coolant temperature recorded in the freeze frame data).
    1. Connect the SSM3 to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn on the SSM3.
    4. Clear the DTC. (Refer to CHECKING/CLEARING DTC )
    5. Turn IG to OFF and wait for at least 30 seconds.
    6. According to the driving pattern described in test drive, drive the vehicle.
    7. Follow the SSM3 on-screen instructions to check the DTC. (Refer to CHECKING/CLEARING DTC )

      Result

      Result Go to
      P050A or P050B is displayed. A
      A DTC is not displayed. B

      A: Complete

      A: Go to next step

  17. Check wiring harness and connector (intake air flow meter sub-assembly - ECM) (Refer to DTC P0107 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE CIRCUIT LOW INPUT; DTC P0108 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE CIRCUIT HIGH INPUT )

    B: Repair or replacement of wiring harness or connector

    A: Go to next step

  18. Intake air flow meter sub-assembly replacement
    1. Replace the intake air flow meter sub-assembly. (refer to INTAKE AIR FLOW METER S/A (FA20) )
      NOTE: If the result of check in Step  9 is normal, go to the next step without replacing the intake air flow meter sub-assembly.

      Next

  19. Confirmation of troubleshooting completion
    CAUTION: In order to perform this operation, the engine must be cold (at a temperature equivalent to the engine coolant temperature recorded in the freeze frame data).
    1. Connect the SSM3 to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn on the SSM3.
    4. Clear the DTC. (Refer to CHECKING/CLEARING DTC )
    5. Turn IG to OFF and wait for at least 30 seconds.
    6. According to the driving pattern described in test drive, drive the vehicle.
    7. Follow the SSM3 on-screen instructions to check the DTC. (Refer to CHECKING/CLEARING DTC )

      Result

      Result Go to
      DTC is not displayed. A
      P050A or P050B is displayed. B

      B: Replacement of the engine control computer (refer to REMOVAL )

      A: Complete

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