LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2021 >> RX 350L AWD >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Smart Access System With Push-Button Start (For Entry Function) - Diagnostics - Symptom Tests >> SMART ACCESS SYSTEM WITH PUSH-BUTTON START (for Entry Function) >> Back Door Entry Lock and Unlock Functions do not Operate [09/2015 - ] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Back Door Entry Lock and Unlock Functions do not Operate [09/2015 - ]: Procedure

  1. CHECK POWER DOOR LOCK CONTROL SYSTEM 
    1. When the door control switch on the multiplex network master switch assembly is operated, check that the doors unlock and lock according to the switch operation.

      Refer to OPERATION CHECK [09/2015 - 08/2019] , or refer to OPERATION CHECK [08/2019 - ]

      OK

      Door locks operate normally.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO POWER DOOR LOCK CONTROL SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2015 - ] 

    Result: 

    OK 

    See step  2

  2. CHECK FOR DTC 
    1. Check for DTCs.

      Body Electrical > Smart Access > Trouble Codes 

      Result

      Result Proceed to
      DTC B27A8 is not output A
      DTC B27A8 is output B

    Result: 

    GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2015 - 12/2017]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [12/2017 - ] 

    Result: 

    See step  3

  3. CHECK WAVE ENVIRONMENT 
    1. Bring the electrical key transmitter sub-assembly approximately 0.3 m (0.984 ft.) from the electrical key antenna (outside luggage compartment) and perform an entry back door open/lock function check.

      Refer to OPERATION CHECK [09/2015 - 08/2019] , or refer to OPERATION CHECK [08/2019 - ]

      GTY646664Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Approximately 0.3 m (0.984 ft.)

      HINT: 

      • Communication may not be possible if the electrical key transmitter sub-assembly is within 0.2 m (0.656 ft.) of the electrical key antenna (outside luggage compartment)
      • When the electrical key transmitter sub-assembly is brought near the electrical key antenna (outside luggage compartment), the possibility of wave interference decreases, and it can be determined if wave interference is causing the problem symptom.
      • If the inspection result is that the problem only occurs in certain locations or at certain times of day, the possibility of wave interference is high. Also, added vehicle components may cause wave interference. If installed, remove them and perform the operation check.
      • There may be wave interference if the vehicle is near broadcasting antennas, large video displays, wireless garage door opener systems, wireless security cameras, home security systems, etc. In this case, move the vehicle to a different location and check if there is any improvement.
      • If a tool for checking radio waves, such as a signal strength meter, is available, move around the area while observing both the LF band (used by the vehicle antenna to form the detection area) and RF band (used by the electrical key transmitter sub-assembly for transmission) to check for locations where there is wave interference.
      • When checking the operation of the entry lock function several times, it can be operated up to 2 times consecutively. To operate the function 3 times or more consecutively, the doors need to be unlocked once. However, this is only for the entry lock function, other door lock operations, such as a wireless door lock operation can be performed consecutively.

      Result

      Result Proceed to
      Entry function does not operate normally A
      Entry function operates normally B

    Result: 

    AFFECTED BY WAVE INTERFERENCE 

    Result: 

    See step  4

  4. READ VALUE USING TECHSTREAM (TR/B DOOR LOCK SW, TR/B DOOR UNLOCK SW) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Smart Access / Data List.
    5. Read the Data List according to the display on the Techstream.

      Body Electrical > Smart Access > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Tr/B-Door Lock SW Back door opener switch assembly (lock switch) ON or OFF ON: Back door opener switch assembly (lock switch) pressed
      OFF: Back door opener switch assembly (lock switch) not pressed
      • Displays whether the back door opener switch assembly (lock switch) is on or off.
      • Use this Data List item to help determine if there is a switch malfunction when the back door lock function does not operate.
      Tr/B-Door Unlock SW Back door opener switch assembly (open switch) ON or OFF ON: Back door opener switch assembly (open switch) pressed
      OFF: Back door opener switch assembly (open switch) not pressed
      • Displays whether the back door opener switch assembly (open switch) is on or off.
      • Use this Data List item to help determine if there is a switch malfunction when the back door open function does not operate.

      Body Electrical > Smart Access > Data List 

      Tester Display
      Tr/B-Door Lock SW
      Tr/B-Door Unlock SW

      OK

      The Techstream display changes correctly in response to the operation of the back door opener switch assembly.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  9

    Result: 

    OK 

    See step  5

  5. CHECK KEY DIAGNOSTIC MODE 
    1. Check the following antenna in key diagnostic mode.

      Body Electrical > Smart Access > Utility 

      Tester Display
      Communication Check(Key Diag Mode)
    2. Select either channel 1 or channel 2 and perform the key diagnostic mode inspection for each channel.
      GTY646664Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a 0.7 to 1 m (2.30 to 3.28 ft.)
      1. Check the electrical key antenna (outside luggage compartment):

        When the electrical key transmitter sub-assembly is brought within 0.7 to 1 m (2.30 to 3.28 ft.) of the electrical key antenna (outside luggage compartment), check that the wireless buzzer sounds.

        HINT: 

        • Select either channel 1 or channel 2 and perform the key diagnostic mode inspection for each channel.
        • If the buzzer sounds with [CH1] displayed but not with [CH2], the electrical key transmitter sub-assembly cannot be detected by channel 2 due to a malfunction, such as wave interference.

      Result

      Result Proceed to
      Wireless buzzer does not sound A
      Wireless buzzer sounds B

    Result: 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [09/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 08/2019]  , or refer to  REMOVAL [08/2019 - ] 

    Result: 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (ELECTRICAL KEY ANTENNA (OUTSIDE LUGGAGE COMPARTMENT) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 
    1. Disconnect the R1 certification ECU (smart key ECU assembly) connector.
    2. Disconnect the W1 electrical key antenna (outside luggage compartment) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      R1-13 (CLG8) - W1-2 (ANTE8) Always Below 1 Ω
      R1-12 (CG8B) - W1-1 (CLGB) Always Below 1 Ω
      R1-13 (CLG8) or W1-2 (ANTE8) - Body ground Always 10 kΩ or higher
      R1-12 (CG8B) or W1-1 (CLGB) - Body ground Always 10 kΩ or higher
    4. Reconnect the W1 electrical key antenna (outside luggage compartment) connector.
    5. Reconnect the R1 certification ECU (smart key ECU assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  7

  7. INSPECT CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO ELECTRICAL KEY ANTENNA (OUTSIDE LUGGAGE COMPARTMENT)) 
    1. Using an oscilloscope, check the waveform.
      GTY653231Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Certification ECU (Smart Key ECU Assembly))
      *b Waveform 1

      OK

      Tester Connection Condition Tool Setting Specified Condition
      R1-13 (CLG8) - J41-18 (E) Procedure:
      1. Engine switch off
      2. Electrical key transmitter sub-assembly brought outside vehicle
      3. All doors closed
      4. Back door opener switch assembly off → on
      2 V/DIV., 500 ms/DIV. Pulse generation
      (See waveform 1)
      R1-12 (CG8B) - J41-18 (E) Procedure:
      1. Engine switch off
      2. Electrical key transmitter sub-assembly brought outside vehicle
      3. All doors closed
      4. Back door opener switch assembly off → on
      2 V/DIV., 500 ms/DIV. Pulse generation
      (See waveform 1)

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ELECTRICAL KEY ANTENNA (OUTSIDE LUGGAGE COMPARTMENT). Refer to  REMOVAL [09/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 12/2017]  , or refer to  REMOVAL [12/2017 - 08/2019]  , or refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    See step  8

  8. CHECK ENTRY LOCK OPERATION 
    1. Connect all connectors and check that the function operates normally.

      Refer to OPERATION CHECK [09/2015 - 08/2019] , or refer to OPERATION CHECK [08/2019 - ]

      Result

      Result Proceed to
      Entry function does not operate normally A
      Entry function operates normally B

    Result: 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [09/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 08/2019]  , or refer to  REMOVAL [08/2019 - ] 

    Result: 

    END (CONNECTOR WAS NOT CONNECTED SECURELY) 

  9. CHECK HARNESS AND CONNECTOR (BACK DOOR OPENER SWITCH ASSEMBLY - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) AND BODY GROUND) 
    1. Disconnect the R1 certification ECU (smart key ECU assembly) connector.
    2. Disconnect the Z8 back door opener switch assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      R1-27 (TSW6) - Z8-1 (L) Always Below 1 Ω
      R1-26 (TSW5) - Z8-3 (UL) Always Below 1 Ω
      Z8-2 (E) - Body ground Always Below 1 Ω
      R1-27 (TSW6) or Z8-1 (L) - Body ground Always 10 kΩ or higher
      R1-26 (TSW5) or Z8-3 (UL) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

  10. INSPECT BACK DOOR OPENER SWITCH ASSEMBLY 
    1. Remove the back door opener switch assembly.

      Refer to REMOVAL [09/2015 - ]

    2. Inspect the back door opener switch assembly.

      Refer to INSPECTION [09/2015 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE BACK DOOR OPENER SWITCH ASSEMBLY. Refer to  REMOVAL [09/2015 - ] 

    Result: 

    OK 

    See step  11

  11. CHECK ENTRY LOCK OPERATION 
    1. Connect all connectors and check that the function operates normally.

      Refer to OPERATION CHECK [09/2015 - 08/2019] , or refer to OPERATION CHECK [08/2019 - ]

      Result

      Result Proceed to
      Entry function does not operate normally A
      Entry function operates normally B

    Result: 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [09/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 08/2019]  , or refer to  REMOVAL [08/2019 - ] 

    Result: 

    END (CONNECTOR WAS NOT CONNECTED SECURELY)