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DTC C1C51-04: Advanced Drive eXtension Control Module System Internal Failure [11/2021 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus LS 500h, 2023 Lexus LS 500h, and 2022 Lexus LS 500h. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK DTC 
    1. Clear the DTCs.

      Chassis > Advanced Drive eXtension Control > Clear DTCs 

    2. Wait at least 5 minutes.
    3. Check for DTCs.

      Chassis > Advanced Drive eXtension Control > Trouble Codes 

      Result

      Result Proceed to
      DTC C1C51-04 is not output A
      DTC C1C51-04 is output B

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - 10/2022]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - 10/2023]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2023 - ] 

    Result: 

    B 

    See step  2

  2. CHECK AIR CONDITIONING SYSTEM 
    1. Refer to Check System Normal Condition.

      Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2017 - 10/2023] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2023 - ]

      Result

      Result Proceed to
      Symptom is normal operation. A
      Symptom is not normal operation. B

    Result: 

    B 

    GO TO AIR CONDITIONING SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2017 - 10/2023]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2023 - ] 

    Result: 

    A 

    See step  3

  3. CHECK ADVANCED DRIVE DUCT 
    1. Check that the No. 2 advanced drive duct and No. 3 advanced drive duct are installed correctly.
    2. Check that the No. 2 advanced drive duct and No. 3 advanced drive duct are not damaged.
    3. Check that there is no foreign matter blockage in the No. 2 advanced drive duct and No. 3 advanced drive duct or in the advanced drive ECU assembly heat sink.

      Result

      Result Proceed to
      No. 2 advanced drive duct is disconnected A
      No. 3 advanced drive duct is disconnected B
      No. 2 advanced drive duct is damaged C
      No. 3 advanced drive duct is damaged D
      There is foreign matter blockage in the No. 2 advanced drive duct and No. 3 advanced drive duct or in the advanced drive ECU assembly heat sink E
      Normal condition F

    Result: 

    A 

    INSTALL NO. 2 ADVANCED DRIVE DUCT. Refer to  INSTALLATION [11/2021 - ] 

    Result: 

    B 

    INSTALL NO. 3 ADVANCED DRIVE DUCT. Refer to  INSTALLATION [11/2021 - ] 

    Result: 

    C 

    REPLACE NO. 2 ADVANCED DRIVE DUCT. Refer to  REMOVAL [11/2021 - ] 

    Result: 

    D 

    REPLACE NO. 3 ADVANCED DRIVE DUCT. Refer to  REMOVAL [11/2021 - ] 

    Result: 

    E 

    REMOVE THE FOREIGN MATTER AND THEN CHECK AGAIN 

    Result: 

    F 

    See step  4

  4. REPLACE ADVANCED DRIVE EXTENSION ECU ASSEMBLY 
    1. Replace the advanced drive extension ECU assembly with a new one.

      Refer to REMOVAL [11/2021 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  5

  5. CHECK DTC 
    1. Clear the DTCs.

      Chassis > Advanced Drive eXtension Control > Clear DTCs 

    2. Wait at least 5 minutes.
    3. Check for DTCs.

      Chassis > Advanced Drive eXtension Control > Trouble Codes 

      Result

      Result Proceed to
      DTC C1C51-04 is not output A
      DTC C1C51-04 is output B

    Result: 

    A 

    END (ADVANCED DRIVE EXTENSION ECU ASSEMBLY IS DEFECTIVE) 

    Result: 

    B 

    REPLACE ADVANCED DRIVE CAMERA. Refer to  REMOVAL [11/2021 - ] 

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