PRE-CRASH SAFETY SYSTEM, Diagnostic DTC:U0235, U1104

DTC Code DTC Name
U0235 Lost Communication with Cruise Control Front Distance Range Sensor
U1104 Lost Communication with Driving Support ECU

DESCRIPTION

The driving support ECU assembly sends vehicle speed and vehicle condition information to the millimeter wave radar sensor assembly. The millimeter wave radar sensor assembly then sends information on the presence, distance, and relative speed of objects ahead to the driving support ECU assembly. The driving support ECU assembly sends this information to the ECM and performs pre-crash safety system operation.

DTC No. Detection Item DTC Detection Condition Trouble Area
U0235 Lost Communication with Cruise Control Front Distance Range Sensor When the engine switch is on (IG), a communication error between the millimeter wave radar sensor assembly and the driving support ECU assembly is detected for approximately 1 second.

  • CAN communication system

  • Millimeter wave radar sensor assembly

  • Driving support ECU assembly
U1104 Lost Communication with Driving Support ECU When the engine switch is on (IG), a communication error between the driving support ECU assembly and the millimeter wave radar sensor assembly is detected for approximately 1 second.

  • CAN communication system

  • Millimeter wave radar sensor assembly

  • Driving support ECU assembly

WIRING DIAGRAM

B00401PE02

CAUTION / NOTICE / HINT

Note


  • When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

    Click here

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

  • When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Using the GTS, check if the CAN communication system is functioning normally.

      Click here

      Result
      Result Proceed to
      CAN communication is normal A
      CAN communication is malfunctioning B

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY POWER SOURCE)


    1. B00409XC42
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly)

      Disconnect the A3 millimeter wave radar sensor assembly connector.

    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
      A3-5 (IGB) - Body ground Engine switch on (IG) 11 to 14 V

    4. Turn the engine switch off.

    5. Reconnect the A3 millimeter wave radar sensor assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - BODY GROUND)


    1. Disconnect the A3 millimeter wave radar sensor assembly connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A3-1 (SGND) - Body ground Always Below 1 Ω

    3. Reconnect the A3 millimeter wave radar sensor assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - BODY GROUND)

    OK

  4. CHECK DRIVING SUPPORT ECU ASSEMBLY (B VOLTAGE)


    1. B003YXEC04
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the F84 driving support ECU assembly connector.

    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
      F84-30 (B) - Body ground Engine switch on (IG) 11 to 14 V

    4. Turn the engine switch off.

    5. Reconnect the F84 driving support ECU assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE POWER SOURCE CIRCUIT

    OK

  5. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Replace the millimeter wave radar sensor assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Perform millimeter wave radar sensor assembly adjustment.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR DTC (PRE-CRASH 2)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Clear the DTCs.

      Click here

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

      Tech Tips

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

    5. Enter the following menus: Body Electrical / Pre-Crash 2 / Trouble Codes.

    6. Check for DTCs.


      Body Electrical > Pre-Crash 2 > Trouble Codes
      Result
      Result Proceed to
      DTC U0235 and U1104 are not output A
      DTC U0235 or U1104 is output B

    7. Turn the engine switch off.


    A

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here