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Diagnosis System

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.
  1. CAN BUS CHECK 
    1. Using the Techstream, select "CAN Bus Check" from the "System Select".
  2. CHECK FOR INSTALLED SYSTEMS (ECUS AND SENSORS) THAT ADOPT CAN COMMUNICATION 
    1. Systems (ECUs, sensors) that adopt CAN communication vary depending on the vehicle's optional settings. Check which systems (ECUs, sensors) are installed on the vehicle
      ECU/SENSOR REFERENCE CHART

      ECU/Sensor Name Check Method
      ECM Installed on all vehicles
      Skid control ECU Installed on all vehicles
      Steering sensor Installed on all vehicles
      Yaw rate sensor Installed on all vehicles
      Power steering ECU Installed on all vehicles
      Center airbag sensor Installed on all vehicles
      Gateway ECU Installed on all vehicles
      Distance control ECU Vehicle with dynamic radar cruise control system
      Seat belt control ECU Vehicle with dynamic radar cruise control system
  3. DTC TABLE BY ECU 

    HINT:

    If CAN communication system DTCs are output, trouble cannot be determined only by the DTCs Perform troubleshooting according to "HOW TO PROCEED WITH TROUBLESHOOTING " . (If however, U0235 or U01102 is output alone, see the dynamic radar cruise control system.)

    1. ECM/Techstream display "Engine"

      HINT

      • DTC communication uses the CAN communication system.
      • Distance control ECU data is also output.
      DTC REFERENCE CHART

      DTC No. Detection Item
      U0100(3) Lost Communication with ECM/PCM "A"
      U0101(1) Lost Communication with Transfer Case Control Module
      U0122(3) Lost Communication with Vehicle Dynamics Control Module
      U0123(3) Lost Communication with Yaw Rate Sensor Module
      U0126(3) Lost Communication with Steering Angle Sensor Module
      U0235 ((2))((3)) Lost Communication with Cruise Control Front Distance Range Sensor
      U1101 ((3)) Lost Communication with Distance Control ECU
      U1102(2)(3) Lost Communication with Radar Sensor
      (1) The ECM is malfunctioning if U0101 is output. Replace the ECM
      (2) If U0235 or U1102 is output alone, the CAN communication is normal (See DTC U0235 LOST COMMUNICATION WITH CRUISE CONTROL FRONT DISTANCE RANGE SENSOR for U0235, CC-94 for U1102).
      (3) Dynamic radar cruise DTC
    2. ECM/Techstream display "ECT"

      HINT:

      • DTC communication uses the CAN communication system.
      DTC COMMUNICATION CHART

      DTC No. Detection Item
      U0100((1)) Lost Communication with ECM/PCM "A"
      (1) The ECM is malfunctioning if U0100 is output.

      Replace ECM.

    3. SKID CONTROL ECU/Techstream display "ABS/ VSC/TRAC"

      HINT:

      DTC communication uses the CAN communication system.

      DTC COMMUNICATION CHART

      DTC No. Detection Item
      U0073 Control Module communication Bus Off
      U0123 Lost Communication with Yaw Rate sensor Module
      U0124 Lost Communication with Lateral Acceleration Sensor Module
      U0126 Lost Communication with Steering Angle Sensor Module
    4. POWER STEERING ECU/Techstream display "EPS"

      HINT.

      DTC communication uses the CAN communication system.

      DTC COMMUNICATION CHART

      DTC No. Detection Item
      U0100 Lost Communication with ECM/PCM "A"
      U0129 Lost Communication with Brake System Control Module
    5. SEAT BELT CONTROL ECU/Techstream display "Pre-Collision"

      HINT:

      DTC communication uses the SIL line.

      DTC COMMUNICATION CHART

      DTC No. Detection Item
      U0100 Lost Communication with ECM/PCM "A"
      U0122 Lost Communication with Vehicle Dynamics Control Module
      U0151 Lost Communication With SRS Airbag ECU
      U1101 Lost Communication with Distance Control ECU
    6. GATEWAY ECU

      HINT.

      The gateway ECU is connected to the CAN communication system, but CAN communication DTCs are not output.

    7. CENTER AIRBAG SENSOR

      HINT.

      The center airbag sensor is connected to the CAN communication system, but CAN communication DTCs are not output.

    8. STEERING ANGLE SENSOR

      HINT:

      The steering angle sensor is connected to the CAN communication system, but CAN communication DTCs are not output

    9. YAW RATE SENSOR

      HINT.

      The yaw rate sensor is connected to the CAN communication system, but CAN communication DTCs are not output.

  4. DTC COMBINATION TABLE 
    DTC COMMUNICATION CHART

    DTC Trouble Mode
    Output from Output DTC Skid Control ECU Communication Stop Mode Steering Angle Sensor Communication Stop Mode Yaw Rate Sensor Communication Stop Mode Gateway ECU Communication Stop Mode ECM Communication Stop Mode
    Skid Control ECU U0073 ◦*1 X X X X
    U0123 □*1 During driving X □ During driving X X
    U0124 □*1 During driving X □ During driving X X
    U0126 □*1 During driving □ During driving X X X
    ECM U0100 X X X X □ Control distance
    U0122 □ Control distance X X X X
    U0123 X X □ Control distance X X
    U0126 X □ Control distance X X X
    U1101 X X X X X
    Power Steering ECU U0100 X X X X ◦
    U0129 ◦ X X X X
    Seat Belt Control ECU U0100 X X X X ◦
    U0122 ◦ X X X X
    U1101 X X X X X
    U0151 X X X X X
    HINT:
    DTC COMMUNICATION CHART

    DTC Trouble Mode
    Output from Output DTC Distance Control ECU Communication Stop Mode Seat Belt Control ECU Communication Stop Mode Power Steering ECU Communication Stop Mode Center Airbag Sensor Communication Stop Mode
    Skid Control ECU U0073 X X X X
    U0123 X X X X
    U0124 X X X X
    U0126 X X X X
    ECM U0100 □*1 Control distance X X X
    U0122 □*1 Control distance X X X
    U0123 □*1 Control distance X X X
    U0126 □*1 Control distance X X X
    U1101 □*1 Control distance X X X
    Power Steering ECU U0100 X X ◦*1 X
    U0129 X X ◦*1 X
    Seat Belt Control ECU U0100 X ◦*1 X X
    U0122 X ◦*1 X X
    U1101 ◦ ◦*1 X X
    U0151 X ◦*1 X ◦
    HINT:
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