PRE-CRASH SAFETY SYSTEM, Diagnostic DTC:U0235, U1002, U1104

DTC Code DTC Name
U0235 Lost Communication with Cruise Control Front Distance Range Sensor
U1002 Lost Communication with Gateway Module
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
U1002 Lost Communication with Gateway Module 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 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

WIRING DIAGRAM

A01HIRZE01

CAUTION / NOTICE / HINT

Note


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

  • 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

  • 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 HARNESS AND CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Disconnect the I19 driving support ECU assembly connector.

    2. Disconnect the A21 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
      I19-40 (CA1P) - A21-3 (CA1P) Always Below 1 Ω
      I19-18 (CA1N) - A21-2 (CA1N) Always Below 1 Ω
      I19-40 (CA1P) - Body ground Always 10 kΩ or higher
      I19-18 (CA1N) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. B0057APC50
      *a

      Rear view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the driving support ECU assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      I19-30 (B) - Body ground Engine switch on (IG)

      11 to 14 V*1

      10.5 to 16 V*2
      I19-30 (B) - Body ground Engine switch off Below 1 V
      *1: w/o Stop and Start System
      *2: w/ Stop and Start System
      Standard Resistance
      Tester Connection Condition Specified Condition
      I19-25 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A01HG4FC57
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly)

      Disconnect the 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 Switch Condition Specified Condition
      A21-5 (IGB) - Body ground Engine switch on (IG)

      11 to 14 V*1

      10.5 to 16 V*2
      A21-5 (IGB) - Body ground Engine switch off Below 1 V
      *1: w/o Stop and Start System
      *2: w/ Stop and Start System
      Standard Resistance
      Tester Connection Condition Specified Condition
      A21-1 (SGND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    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


    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
      Result
      Result Proceed to
      DTC U0235, U1002 and U1104 are not output A
      DTC U0235, U1002 or U1104 is output B

    A

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here