DYNAMIC RADAR CRUISE CONTROL SYSTEM, Diagnostic DTC:U1102

DTC Code DTC Name
U1102 Lost Communication with Radar Sensor

DESCRIPTION

The millimeter wave radar sensor and driving support ECU transmit the data for general vehicle control and diagnosis function along the communication line. The driving support ECU determines the curve radius information based on signals from the steering wheel and yaw rate and acceleration sensor. The driving support ECU transmits the current vehicle speed and curve radius information to the millimeter wave radar sensor.

DTC No. DTC Detection Condition Trouble Area
U1102 The ECM detects a communication error signal (from the driving support control ECU to the millimeter wave radar sensor) for 0.15 sec. or more while the dynamic radar cruise control is in operation

  • Communication circuit

  • Millimeter wave radar sensor

  • Driving support ECU

WIRING DIAGRAM

A019OHXE25

INSPECTION PROCEDURE

Note

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

PROCEDURE


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


    1. A019NJNE06
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor)
      *2

      Front view of wire harness connector

      (to Driving Support ECU)

      Disconnect the driving support ECU and millimeter wave radar sensor connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C1-38 (LRRD) - B1-4 (LRRD) Always Below 1 Ω
      C1-38 (LRRD) - Body ground Always 10 kΩ or higher

    3. Reconnect the driving support ECU and millimeter wave radar sensor connectors.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A019LQPE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor)

      Disconnect the millimeter wave radar sensor 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
      B1-5 (IGB) - Body ground Engine switch on (IG) 11 to 14 V

    4. Reconnect the millimeter wave radar sensor connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A019KOVE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor)

      Disconnect the millimeter wave radar sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B1-2 (SGND) - Body ground Always Below 1 Ω

    3. Reconnect the millimeter wave radar sensor connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK MILLIMETER WAVE RADAR SENSOR


    1. A019MFKE05
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Driving Support ECU)

      Disconnect the driving support ECU 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
      C1-38 (LRRD) - Body ground Engine switch on (IG) 4.5 to 5.5 V

    4. Reconnect the driving support ECU connector.


    NG

    REPLACE MILLIMETER WAVE RADAR SENSOR Click here

    OK

  5. REPLACE DRIVING SUPPORT ECU


    1. Replace the driving support ECU Click here.


    NEXT

  6. CHECK DTC OUTPUT


    1. Clear the DTCs Click here.

    2. 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 of 50 km/h (31 mph) or more.

      2. Turn the cruise control main switch on.

    3. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC is not output A
      DTC U1102 is output B

    B

    REPLACE MILLIMETER WAVE RADAR SENSOR Click here

    A

    END