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Home >> Lexus >> 2015 >> ES 300h >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Cruise Control Systems >> Dynamic Radar Cruise Control System (Diagnostic Codes & Circuit Tests) >> Dynamic Radar Cruise Control System >> DTC U0125: Lost Communication with Yaw Rate Sensor Module; DTC U0126: Lost Communication with Steering Angle Sensor Module; DTC U0129: Lost Communication with Brake System Control Module; DTC U0293: Lost Communication with HV ECU; DTC U1104: Lost Communication with Driving Support ECU [08/2014 - ] >> Procedure
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DTC U0125: Lost Communication with Yaw Rate Sensor Module; DTC U0126: Lost Communication with Steering Angle Sensor Module; DTC U0129: Lost Communication with Brake System Control Module; DTC U0293: Lost Communication with HV ECU; DTC U1104: Lost Communication with Driving Support ECU [08/2014 - ]: Procedure

  1. CHECK FOR DTCs (RADAR CRUISE) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
    5. Read the DTCs.

      Result

      Result Proceed to
      DTC U1104 is output A
      DTCs other than U1104 are output B
    6. Turn the power switch off.

    B → See step   6 

    A: Go to next step 

  2. CHECK CAN COMMUNICATION SYSTEM 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Select "CAN Bus Check" from the "System Selection Menu" screen on the Techstream.
    4. Select "Communication Malfunction DTC" from the "CAN Bus Check" screen, and then select "Enter".

      OK

      Communication system is normal.

    5. Turn the power switch off.

    NG → See step   6 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - BODY GROUND) 
    1. Disconnect the H75 driving support ECU assembly connector.
    2. Measure the resistance according to the value(s) in the table below.
      GTY416105Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      H75-25 (GND) - Body ground Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Driving Support ECU Assembly)
    3. Reconnect the H75 driving support ECU assembly connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. REPLACE DRIVING SUPPORT ECU ASSEMBLY 

    Refer to REMOVAL [08/2014 - ]

    NEXT: Go to next step 

  5. CHECK FOR DTCs (RADAR CRUISE) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2014 - ] .
    4. Perform the following to make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the malfunction cannot be detected.

      1. Drive the vehicle at a speed for which cruise control operation is possible.
      2. Turn the cruise control switch on.
      3. Push the -SET switch to activate the cruise control.
    5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
    6. Read the DTCs.

      Result

      Result Proceed to
      DTC is not output A
      DTC U1104 is output B
    7. Turn the power switch off.

    B → See step   7 

    A → END 

  6. GO TO CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2014 - ] 
  7. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [08/2014 - ]