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Home >> Scion >> 2016 >> FR-S Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostic Codes (P000A-P0230)) >> SFI System >> DTC P0072: Ambient Air Temperature Sensor Circuit Low Input; DTC P0073: Ambient Air Temperature Sensor Circuit High Input [05/2014 - ] >> Procedure
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DTC P0072: Ambient Air Temperature Sensor Circuit Low Input; DTC P0073: Ambient Air Temperature Sensor Circuit High Input [05/2014 - ]: Procedure

  1. CHECK DTC OUTPUT (CAN COMMUNICATION SYSTEM) 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Trouble Codes.
    5. Read DTCs.
      RESULT

      Result Proceed to
      DTC is not output A
      DTC is output B

    B → See step   7 

    A: Go to next step 

  2. CHECK DTC OUTPUT (METER AND GAUGE SYSTEM) 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Combination Meter / Trouble Codes.
    5. Read DTCs.
      RESULT

      Result Proceed to
      DTC is not output A
      DTC B1509 is output B

    B → See step   6 

    A: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (AMBIENT AIR TEMPERATURE SENSOR - COMBINATION METER ASSEMBLY) 
    1. Disconnect the ambient air temperature sensor connector.
    2. Disconnect the combination meter assembly connector.
    3. Measure the resistance according to the value(s) in the chart below.

      Standard Resistance (Check for open)

      Tester Connection Condition Specified Condition
      A48-1 - D7-24 (TAM) Always Below 1 Ω
      A48-2 - D7-25 (SG-) Always Below 1 Ω

      Standard Resistance (Check for short)

      Tester Connection Condition Specified Condition
      A48-1 or D7-24 (TAM) - Body ground Always 10 kΩ or higher
      A48-2 or D7-25 (SG-) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. INSPECT AMBIENT AIR TEMPERATURE SENSOR 
    1. Inspect the ambient air temperature sensor. Refer to INSPECTION [05/2014 - ] .

    NG → See step   10 

    OK: Go to next step 

  5. CHECK WHETHER DTC OUTPUT RECURS 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream on.
    4. Clear the DTCs. Refer to DTC CHECK / CLEAR [05/2014 - ] .
    5. Turn the ignition switch off and wait for at least 30 seconds.
    6. Turn the ignition switch to ON and turn the Techstream on.
    7. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
    8. Enter the following menus: Powertrain / Engine / Trouble Codes.
    9. Read DTCs.
      RESULT

      Result Proceed to
      DTC is not output A
      DTC P0072 or P0073 is output B

    B → See step   8 

    A → See step   9 

  6. GO TO METER / GAUGE SYSTEM. Refer to  DTC B1509: OPEN IN AMBIENT TEMPERATURE SENSOR CIRCUIT [05/2014 - ] 
  7. GO TO CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [05/2014 - ] 
  8. REPLACE ECM. Refer to  REMOVAL [05/2014 - ] 
  9. CHECK FOR INTERMITTENT PROBLEMS. Refer to  CHECK FOR INTERMITTENT PROBLEMS [05/2014 - ] 
  10. REPLACE AMBIENT AIR TEMPERATURE SENSOR. Refer to  REMOVAL [05/2014 - ] 
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