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 transmit the data for general vehicle control and the diagnosis function through the communication line.

The driving support ECU estimates the curve information based on the signal from the steering wheel and yaw rate sensor.

The driving support ECU transmits the current vehicle speed and estimates curve information to the millimeter wave radar sensor assembly.

DTC Code DTC Detection Condition Trouble Area
U1102 While the vehicle speed is 50 km/h (31 mph) or more with the cruise control switch on, a communication stop between the millimeter wave radar sensor and driving support ECU continues for 1 second or more.

  • Harness or connector

  • Driving support ECU

  • Millimeter wave radar sensor assembly

WIRING DIAGRAM

A0099IDE02

INSPECTION PROCEDURE

Note


  • When the driving support ECU is replaced with a new one, initialization must be performed Click here.

  • When the millimeter wave radar sensor 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.

  • Confirm that the connector is securely connected, as a partially connected connector may be the cause of this DTC.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR - BATTERY AND BODY GROUND)

    Note

    A DTC is stored when the following inspection is performed. Be sure to clear the DTC after performing this inspection.


    1. A0098MSE06
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly)

      Disconnect the A15 sensor connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A15-5 (IGB) - Body ground Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A15-2 (SGND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU - BODY GROUND)


    1. A0099V9E05
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Driving Support ECU)

      Disconnect the G119 ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G119-25 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR - DRIVING SUPPORT ECU)


    1. Disconnect the A15 sensor connector.

    2. Disconnect the G119 ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A15-4 (LRRD) - G119-38 (LRRD) Always Below 1 Ω
      A15-4 (LRRD) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE DRIVING SUPPORT ECU


    1. Replace the driving support ECU Click here.


    NEXT

  5. CHECK FOR DTC


    1. Clear the DTCs Click here.

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

      Tech Tips

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


      1. Drive the vehicle at a speed of 50 km/h (31 mph) or more.

      2. Turn the cruise control switch on.

    3. Check for DTCs Click here.

      OK
      DTC U1102 is not output.

    NG

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

    OK

    END (DRIVING SUPPORT ECU IS DEFECTIVE)