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 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 2 seconds.

  • 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), there is a communication error between the driving support ECU and the millimeter wave radar sensor assembly, brake actuator assembly (skid control ECU) or ECM for 4 seconds or more.

  • CAN communication system

  • Millimeter wave radar sensor assembly

  • Driving support ECU assembly

  • Brake actuator assembly (skid control ECU)

  • ECM

WIRING DIAGRAM

A01VSEKE14

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


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


    1. Disconnect the Q1 driving support ECU assembly connector.

    2. Disconnect the B7 millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q1-40 (CA1P) - B7-3 (CA1P) Always Below 1 Ω
      Q1-18 (CA1N) - B7-2 (CA1N) Always Below 1 Ω
      Q1-40 (CA1P) or B7-3 (CA1P) - Body ground Always 10 kΩ or higher
      Q1-18 (CA1N) or B7-2 (CA1N) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF DRIVING SUPPORT ECU ASSEMBLY)


    1. A01VSJUC57
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the Q1 driving support ECU assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Q1-30 (B) - Body ground Engine switch on (IG) 11 to 14 V
      Q1-30 (B) - Body ground Engine switch off Below 1 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      Q1-25 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - BATTERY AND BODY GROUND)

    OK

  3. CHECK TERMINAL VOLTAGE (POWER SOURCE OF MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. B007695C65
      *a

      Front view of wire harness connector

      (to Millimeter Wave radar sensor assembly)

      Disconnect the B7 millimeter wave radar sensor assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      B7-5 (IGB) - Body ground Engine switch on (IG) 11 to 14 V
      B7-5 (IGB) - Body ground Engine switch off Below 1 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      B7-1 (SGND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  4. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Replace the millimeter wave radar sensor assembly with a new one.

      Click here

    2. Perform millimeter wave radar sensor assembly adjustment.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR DTCs (PRE-CRASH 2)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Crash 2 > Clear DTCs

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

      Tech Tips

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

    3. Check for DTCs.

      Click here


      Body Electrical > Pre-Crash 2 > Trouble Codes

      Note

      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.

      Result
      Result Proceed to
      DTC U0235 and U1104 are not output A
      DTC U0235 or U1104 is output B

    A

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here