DYNAMIC RADAR CRUISE CONTROL SYSTEM, Diagnostic DTC:U1102

DTC Code DTC Name
U1102 Lost Communication with Radar Sensor

DESCRIPTION

The millimeter wave radar sensor assembly and driving support ECU assembly transmit the data for general vehicle control and diagnosis function via CAN communication. The driving support ECU assembly determines the curve radius information based on signals from the spiral cable sub-assembly and airbag sensor assembly (yaw rate sensor). The driving support ECU assembly transmits the current vehicle speed and curve radius information to the millimeter wave radar sensor assembly.

DTC No. Detection Item DTC Detection Condition Trouble Area
U1102 Lost Communication with Radar Sensor The ECM detects a communication error signal (from the driving support control ECU assembly to the millimeter wave radar sensor assembly) for approximately 0.15 seconds or more while the dynamic radar cruise control is operating.

  • Millimeter wave radar sensor assembly

  • Millimeter wave radar sensor circuit

  • Driving support ECU assembly

WIRING DIAGRAM

Refer to the wiring diagram for DTC U0235.

Click here

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 procedure.

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. Adjust the millimeter wave radar sensor assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR DTCS (DTC U1102)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Clear the DTCs.

      Click here

    4. Perform the following to make sure that the DTC detection conditions are met.

      Tech Tips

      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 dynamic radar cruise control system on using the cruise control main switch (ON-OFF button).

      3. Push the cruise control main switch to -SET to activate the dynamic radar cruise control system.

    5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.

    6. Check for DTCs.


      Powertrain > Radar Cruise > Trouble Codes
      Result
      Result Proceed to
      DTCs are not output A
      DTC U1102 is output B

    7. Turn the engine switch off.


    A

    END

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here