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Home >> Lexus >> 2020 >> ES 300h Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 85 (Pre-Collision System (Except Hybrid) - Diagnostic Codes) >> PRE-COLLISION SYSTEM (for Gasoline Model) >> DTC U023A-87: Lost Communication with Image Processing Module "A" Missing Message [06/2018 - 08/2021] >> Procedure

DTC U023A-87: Lost Communication with Image Processing Module "A" Missing Message [06/2018 - 08/2021]: Procedure

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  1. CHECK FOR DTCs 
    1. Using the Techstream, check for electronically controlled brake system DTCs.

      Chassis > Brake/EPB > Trouble Codes 

      HINT: 

      If DTC U023A-87 and electronically controlled brake system DTCs are output, perform troubleshooting for the electronically controlled brake system first.

      Result

      Result Proceed to
      Electronically controlled brake system DTCs are not output A
      Electronically controlled brake system DTCs are output B

    Result: 

    GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2018 - ] 

    Result: 

    See step  2

  2. PERFORM DEALER MODE (SIGNAL CHECK) (ELECTRONICALLY CONTROLLED BRAKE SYSTEM) 

    HINT: 

    When entering Dealer Mode (Signal Check), the skid control ECU (brake actuator assembly) communicates with the forward recognition camera to judge whether the vehicle is equipped with the pre-collision system. Therefore, do not exit Dealer Mode (Signal Check) within 5 seconds of entering Dealer Mode (Signal Check).

    1. Procedure to enter Dealer Mode (Signal Check)
      1. Turn the engine switch off.
      2. Apply the parking brake.
      3. Check that the shift lever is in P.
      4. Connect the Techstream to the DLC3.
      5. Turn the engine switch on (IG).
      6. Check that the steering wheel is centered.
      7. Turn the Techstream on.
      8. Switch the skid control ECU (brake actuator assembly) to Dealer Mode (Signal Check) using the Techstream. Enter the following menus: Chassis / Brake/EPB / Utility / Signal Check.

        Chassis > Brake/EPB > Utility 

        Tester Display
        Signal Check

        HINT: 

        Do not exit Dealer Mode (Signal Check) within 5 seconds of entering Dealer Mode (Signal Check). If Dealer Mode (Signal Check) is exited within 5 seconds of entering Dealer Mode (Signal Check), DTC U023A-87 may be stored. If DTC U023A-87 is output after exiting Dealer Mode (Signal Check), enter Dealer Mode (Signal Check) again, wait at least 5 seconds, then recheck for DTCs.

    2. Confirm the system has entered Dealer Mode (Signal Check).
      1. Confirm that the ABS warning light and slip indicator light indicate the Dealer Mode pattern (blinking at 0.25 second intervals).

        HINT: 

        • If the ABS warning light or slip indicator light remains illuminated or does not illuminate when Dealer Mode (Signal Check) is entered, a component or wire harness may be malfunctioning.
        • When entering Dealer Mode (Signal Check), if the parking brake is engaged, the parking brake indicator light (red) will illuminate, and if the parking brake is not engaged, the parking brake indicator light (red) will blink in the Dealer Mode pattern (blinking at 0.25 second intervals).
    3. End of Dealer Mode (Signal Check)
      1. Turn the engine switch off.
      2. Disconnect the Techstream.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  3

  3. CHECK FOR DTCs 
    1. Clear the DTCs.

      Body Electrical > Pre-Collision System > Clear DTCs 

    2. Make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the system cannot detect the malfunction.

    3. Check for DTCs.

      Body Electrical > Pre-Collision System > Trouble Codes 

      Result

      Result Proceed to
      DTC U023A-87 is not output A
      DTC U023A-87 is output B

    Result: 

    END 

    Result: 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  COMPONENTS [06/2018 - ]