CAN COMMUNICATION SYSTEM(for LHD), Diagnostic DTC:U1118

DTC Code DTC Name
U1118 Lost Communication with Rear Radar Sensor

DESCRIPTION

DTC Code DTC Detection Condition Trouble Area
U1118 There is no communication from the rear millimeter wave radar sensor assembly.

  • Power source or inside of rear millimeter wave radar sensor assembly

  • Rear millimeter wave radar sensor assembly CAN branch wire or connector

  • Driving support ECU assembly

  • Rear millimeter wave radar sensor assembly

WIRING DIAGRAM

A000WH1E01
*a No. 14 Junction Connector
*b Driving Support ECU Assembly
*c Rear Millimeter Wave Radar Sensor Assembly

CAUTION / NOTICE / HINT

Note

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

Tech Tips

Operating the power switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

PROCEDURE


  1. PRECAUTION

    Note

    After turning the power switch off, waiting time may be required before disconnecting the cable from the auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the auxiliary battery terminal notice before proceeding with work Click here.


    NEXT

  2. DISCONNECT CABLE FROM NEGATIVE AUXILIARY BATTERY TERMINAL


    1. Disconnect the cable from the negative (-) auxiliary battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.


    NEXT

  3. CHECK FOR OPEN IN CAN BUS WIRE (REAR MILLIMETER WAVE RADAR SENSOR ASSEMBLY CAN BRANCH WIRE)


    1. A000V0ME01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Rear Millimeter Wave Radar Sensor Assembly)

      Disconnect the rear millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      R51-4 (CA1P) - R51-3 (CA1N) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE REAR MILLIMETER WAVE RADAR SENSOR ASSEMBLY CAN BRANCH WIRE OR CONNECTOR (CA1P, CA1N)

    OK

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


    1. A000Y6CE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Rear Millimeter Wave Radar Sensor Assembly)

      Connect the cable to the negative (-) auxiliary battery terminal.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      R51-5 (IGB2) - Body ground Power switch on (IG) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      R51-2 (RGND) - Body ground Always Below 1 Ω

    OK

    REPLACE REAR MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

    NG

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


    1. Disconnect the A33 driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A33-37 (IGB2) - R51-5 (IGB2) Always Below 1 Ω
      A33-9 (RGND) - R51-2 (RGND) Always Below 1 Ω
      A33-37 (IGB2) - Body ground Always 10 kΩ or higher
      A33-26 (RGND) - Body ground Always 10 kΩ or higher

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR