LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2017 >> IS 350 Base, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Drivers Assistance Systems - ADAS >> Lane Departure Alert System (W/ Steering Control) - Diagnostic Codes & Circuit Tests >> LANE DEPARTURE ALERT SYSTEM (w/ Steering Control) >> DTC U0235: Lost Communication with Cruise Control Front Distance Range Sensor; DTC U1104: Lost Communication with Driving Support ECU [10/2016 - 09/2020] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC U0235: Lost Communication with Cruise Control Front Distance Range Sensor; DTC U1104: Lost Communication with Driving Support ECU [10/2016 - 09/2020]: Procedure

  1. READ VALUE USING TECHSTREAM (CAN BUS CHECK) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: System Select / Can Bus Check.

      Refer to DIAGNOSIS SYSTEM [10/2016 - 10/2017] , or refer to DIAGNOSIS SYSTEM [10/2017 - 09/2018] , or refer to DIAGNOSIS SYSTEM [09/2018 - 09/2020]

      CAN Bus Check 

      Result

      Result Proceed to
      All of the ECUs and sensors that are currently connected to the CAN communication system are displayed A
      None of the ECUs and sensors that are currently connected to the CAN communication system are displayed, or some of them are not displayed B

    Result: 

    B 

    GO TO CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2016 - 09/2018]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2018 - ] 

    Result: 

    A 

    See step  2

  2. CHECK FOR DTCs (CAN COMMUNICATION DTC OUTPUT) 

    HINT: 

    When pre-collision system DTC U1002 is output, check that the local bus is functioning normally by performing the diagnostic procedure for U1002.

    1. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2016 - 09/2020]

      Body Electrical > Pre-Collision 2 > Trouble Codes 

      Result

      Result Proceed to
      DTC U1002 is not output A
      DTC U1002 is output B

    Result: 

    B 

    GO TO PRE-COLLISION SYSTEM. Refer to  DTC U1002: Lost Communication with Gateway Module [10/2016 - 09/2018]  , or refer to  DTC U1002: Lost Communication with Gateway Module [09/2018 - 09/2020] 

    Result: 

    A 

    See step  3

  3. CHECK CAN BUS LINE 
    1. Turn the engine switch off.
    2. Disconnect the cable from the negative (-) battery terminal.
    3. Disconnect the S18 forward recognition camera connector.
      GTY645455Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Forward Recognition Camera)
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      S18-6 (CANH) - S18-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

      HINT: 

      If the result is not as specified, a malfunction in a CAN communication line is suspected.

    5. Connect the S18 forward recognition camera connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (CAN BUS LINE) 

    Result: 

    OK 

    See step  4

  4. CHECK FOR DTCs (LANE DEPARTURE ALERT SYSTEM) 
    1. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2016 - 09/2020]

      Chassis > LKA/LDA > Trouble Codes 

      Result

      Result Proceed to
      DTC U0235 and U1104 are output A
      Only DTC U1104 is output B
      Only DTC U0235 is output C

    Result: 

    B 

    See step  7

    Result: 

    C 

    See step  10

    Result: 

    A 

    See step  5

  5. CHECK POWER SOURCE CIRCUIT (DRIVING SUPPORT ECU ASSEMBLY) 
    1. Disconnect the M2 driving support ECU assembly connector.
      GTY668890Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Driving Support ECU Assembly)
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      M2-7 (B) - Body ground Engine switch on (IG) 11 to 14 V
    4. Turn the engine switch off.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      M2-28 (GND) - Body ground Always Below 1 Ω
    6. Reconnect the M2 driving support ECU assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

    Result: 

    OK 

    See step  6

  6. CHECK POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the B10 millimeter wave radar sensor assembly connector.
      GTY660297Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Sensor Assembly)
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      B10-8 (IGB) - Body ground Engine switch on (IG) 11 to 14 V
    4. Turn the engine switch off.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      B10-1 (SGND) - Body ground Always Below 1 Ω
    6. Reconnect the B10 millimeter wave radar sensor assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  COMPONENTS [10/2016 - 09/2020] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

  7. CHECK POWER SOURCE CIRCUIT (DRIVING SUPPORT ECU ASSEMBLY) 
    1. Disconnect the M2 driving support ECU assembly connector.
      GTY668890Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Driving Support ECU Assembly)
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      M2-7 (B) - Body ground Engine switch on (IG) 11 to 14 V
    4. Turn the engine switch off.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      M2-28 (GND) - Body ground Always Below 1 Ω
    6. Reconnect the M2 driving support ECU assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

    Result: 

    OK 

    See step  8

  8. REPLACE DRIVING SUPPORT ECU ASSEMBLY 
    1. Replace the driving support ECU assembly.

      Refer to REMOVAL [04/2013 - 09/2020]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  9

  9. CHECK FOR DTCs (LANE DEPARTURE ALERT SYSTEM) 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2016 - 09/2020]

      Chassis > LKA/LDA > Clear DTCs 

    2. Perform the following procedure.

      HINT: 

      If the following procedure is not performed, the previously output DTC cannot be detected.

      1. Turn the engine switch on (IG) and wait 7 seconds or more.
    3. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2016 - 09/2020]

      Chassis > LKA/LDA > Trouble Codes 

      Result

      Result Proceed to
      DTC U1104 is not output A
      DTC U1104 is output B

    Result: 

    A 

    END (DRIVING SUPPORT ECU ASSEMBLY WAS DEFECTIVE) 

    Result: 

    B 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  COMPONENTS [10/2016 - 09/2020] 

  10. CHECK POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) 
    1. Disconnect the B10 millimeter wave radar sensor assembly connector.
      GTY660297Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Millimeter Wave Radar Sensor Assembly)
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      B10-8 (IGB) - Body ground Engine switch on (IG) 11 to 14 V
    4. Turn the engine switch off.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      B10-1 (SGND) - Body ground Always Below 1 Ω
    6. Reconnect the B10 millimeter wave radar sensor assembly connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

    Result: 

    OK 

    See step  11

  11. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY 
    1. Replace the millimeter wave radar sensor assembly.

      Refer to REMOVAL [10/2016 - 09/2020]

    2. Adjust the millimeter wave radar sensor assembly.

      Refer to ADJUSTMENT [10/2016 - 09/2020]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  12

  12. CHECK FOR DTCs (LANE DEPARTURE ALERT SYSTEM) 
    1. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2016 - 09/2020]

      Chassis > LKA/LDA > Clear DTCs 

    2. Perform the following procedure.

      HINT: 

      If the following procedure is not performed, the previously output DTC cannot be detected.

      1. Turn the engine switch on (IG) and wait 7 seconds or more.
    3. Check for DTCs.

      Refer to DTC CHECK / CLEAR [10/2016 - 09/2020]

      Chassis > LKA/LDA > Trouble Codes 

      Result

      Result Proceed to
      DTC U0235 is not output A
      DTC U0235 is output B

    Result: 

    A 

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE) 

    Result: 

    B 

    REPLACE FORWARD RECOGNITION CAMERA. Refer to  COMPONENTS [10/2016 - 09/2020] 

scientia non olet · About LEMON Manuals