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Home >> Toyota >> 2025 >> GR86 Base, Automatic Trans >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Drivers Assistance Systems - ADAS >> Eyesight System - Diagnostic Codes (1 Of 2) >> Eyesight System >> DTC B2C08: RRC Sonar Sensor Circuit / No Signal; DTC B2C09: RRC Sonar Sensor Circuit / Sonar Control Module Circuit [11/2021 - ] >> Procedure
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DTC B2C08: RRC Sonar Sensor Circuit / No Signal; DTC B2C09: RRC Sonar Sensor Circuit / Sonar Control Module Circuit [11/2021 - ]: Procedure

  1. CHECK CONNECTOR 
    1. Turn the ignition switch to OFF.
    2. Disconnect the rear corner ultrasonic sensor RH connector.

      Refer to REMOVAL [11/2021 - ]

    3. Connect the disconnected connectors.
    4. Turn the ignition switch to ON.
    5. Check for DTCs.

      Body Electrical > Reverse Automatic Braking > Trouble Codes 

      Is DTC B2C08 displayed? (Current code)

      Result Proceed to
      YES A
      NO (Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.)
      HINT: 
      In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
      B

    Result: 

    EVEN IF DTC IS DISPLAYED, THE CIRCUIT HAS RETURNED TO A NORMAL CONDITION AT THIS TIME. REPRODUCE THE FAILURE, AND THEN PERFORM THE DIAGNOSIS AGAIN. 

    Result: 

    See step  2

  2. CHECK BETWEEN SONAR SENSOR CONNECTOR AND CLEARANCE WARNING ECU ASSEMBLY CONNECTOR. (OPEN CIRCUIT) 
    1. Turn the ignition switch to OFF.
    2. Disconnect the rear center ultrasonic sensor RH connector and the clearance warning ECU assembly connector.

      Refer to REMOVAL [11/2021 - ]

      Refer to REMOVAL [11/2021 - ]

    3. Using a tester, measure resistance of the harness between the rear center ultrasonic sensor RH connector and clearance warning ECU assembly connector.

      Connector & terminal

      O8-24(RRC+) - Q3-2

      O8-9(RRC-) - Q3-1

      Is the resistance less than 10 Ω?

      Result Proceed to
      YES A
      NO (Repair or replace the open circuit in the harness between sonar sensor connector and clearance warning ECU assembly connector.) B

    Result: 

    REPAIR OR REPLACE THE OPEN CIRCUIT IN THE HARNESS BETWEEN SONAR SENSOR CONNECTOR AND CLEARANCE WARNING ECU ASSEMBLY CONNECTOR. 

    Result: 

    See step  3

  3. CHECK SONAR SENSOR. 
    1. Switch the rear center ultrasonic sensor RH and rear corner ultrasonic sensor RH.

      Refer to REMOVAL [11/2021 - ]

    2. Connect the disconnected connectors.
    3. Turn the ignition switch to ON.
    4. Check for DTCs.

      Body Electrical > Reverse Automatic Braking > Trouble Codes 

      Is DTC B2C08 displayed? (Current code)

      Result Proceed to
      YES (Replace the clearance warning ECU assembly.) A
      NO (Replace the sensor installed as a rear center ultrasonic sensor RH.) B

    Result: 

    REPLACE THE CLEARANCE WARNING ECU ASSEMBLY. Refer to  REMOVAL [11/2021 - ] 

    Result: 

    REPLACE THE SENSOR INSTALLED AS A REAR CENTER ULTRASONIC SENSOR RH.. Refer to  REMOVAL [11/2021 - ]