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HOMESERVICE MANUALSLEXUS2010LS 460L AWDREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE MECHANICALSTARTERSMART ACCESS SYSTEM (KEYLESS START) (DIAGNOSTIC CODES & SYMPTOM TESTS)SMART ACCESS SYSTEM WITH PUSH-BUTTON STARTDTC B2275: STSW MONITOR MALFUNCTIONPROCEDURE
2010 Lexus LS 460L AWD

DTC B2275: STSW Monitor Malfunction: Procedure

2010 Lexus LS 460L AWDSECTION Procedure
  1. CHECK WHETHER DTC OUTPUT RECURS 
    1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
    2. Depress the brake pedal with the engine switch on (IG), wait at least 15 seconds, and check whether DTC B2275 recurs.

      Result

      Display (DTC output) Proceed to
      B2275 A
      No DTC output B

    B → END (MAIN BODY ECU FAULTY) 

    A: Go to next step 

  2. CHECK MAIN BODY ECU (STSW VOLTAGE) 
    1. Disconnect the A68 main body ECU connector.
      Fig 1: Identifying A68 Main Body ECU Connector
      GTY288072Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. With the shift lever in P or N, depress the brake pedal fully.
    3. Measure the voltage according to the value(s) in the table below.

      HINT: 

      The voltage is generated at terminal STSW for 0.3 seconds when the engine cranks.

      Standard voltage

      Tester Connection Condition Specified Condition
      A68-4 (STSW) - Body ground When operating the engine switch to crank the engine. 11 to 14 V

    OK → See step   4 

    NG: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ECM) 
    Fig 2: Identifying Connector Terminals Of A68 Main Body ECU
    GTY286283Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the A68 main body ECU connector.
    2. Disconnect the A14 ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Condition Specified Condition
      A68-4 (STSW) - A14-27 (STSW) Always Below 1 Ω
      A68-4 (STSW) or A14-27 (STSW) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. CHECK MAIN BODY ECU (OPERATION) 
    1. Temporarily replace the main body ECU with a new or normally functioning one.
    2. Check that the engine starts normally.

      OK

      Engine starts normally.

    NG → See step   5 

    OK → END (MAIN BODY ECU FAULTY) 

  5. GO TO SFI SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.