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DTC U1236-87: Lost Communication with Cruise Control Front Distance Range Sensor Front Side "B" Missing Message [10/2023 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus LS 500. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK CAN MAIN WIRE (FRONT SIDE RADAR SENSOR (B)) 

    Pre-procedure1

    1. Disconnect the cable from the negative (-) battery terminal.
    2. Disconnect the A126 front side radar sensor (B) connector.

      Procedure1

    3. Measure the resistance according to the value (s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A126-5 (CA2P) - A126-6 (CA2N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      A126-5 (CA2P) - Body ground Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A126-6 (CA2N) - Body ground Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A126-5 (CA2P) - +B Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      A126-6 (CA2N) - +B Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. None

    Result: 

    NG 

    See step  3

    Result: 

    OK 

    See step  2

  2. CHECK FRONT SIDE RADAR SENSOR (B) 

    Pre-procedure1

    1. Disconnect the A127 front side radar sensor (A) connector.

      Procedure1

    2. Measure the waveform according to the value (s) in the table below.

      Standard

      Tester Connection Condition Tool Setting Specified Condition
      A127-5 (CA2P) - A127-6 (CA2N) Ignition switch ON 1 V/DIV., 100 μs./DIV. Pulse generation

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    3. None

    Result: 

    OK 

    REPLACE FRONT SIDE RADAR SENSOR (A). Refer to  REMOVAL [10/2023 - ] 

    Result: 

    NG 

    REPLACE FRONT SIDE RADAR SENSOR (B). Refer to  REMOVAL [10/2023 - ] 

  3. CHECK CAN MAIN WIRE (FRONT SIDE RADAR SENSOR (A)) 

    Pre-procedure1

    1. Disconnect the A127 front side radar sensor (A) connector.

      Procedure1

    2. Measure the resistance according to the value (s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A127-5 (CA2P) - A127-6 (CA2N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      A127-5 (CA2P) - Body ground Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A127-6 (CA2N) - Body ground Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A127-5 (CA2P) - +B Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      A127-6 (CA2N) - +B Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    3. None

    Result: 

    OK 

    REPLACE FRONT SIDE RADAR SENSOR (A). Refer to  REMOVAL [10/2023 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR