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Home >> Lexus >> 2007 >> RX 400h AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 331 (Can Communication System) >> Can Communication System >> Diagnosis System

Diagnosis System

WARNING: This page is about a different car, the 2008 Toyota RAV4. 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 INSTALLED SYSTEMS (ECUS AND SENSORS) THAT USE CAN COMMUNICATION 
    1. System (ECUs and sensors) that use CAN communication vary depending on the vehicle's optional settings. Check which systems (ECUs and sensors) are installed on the vehicle.
      ECU AND SENSOR NAME REFERENCE

      ECU / Sensor name Installed to
      ABS and traction actuator (skid control ECU) Vehicle with VSC
      Steering sensor Vehicle with VSC
      Yaw rate sensor Vehicle with VSC
      Air conditioning amplifier All vehicles (Automatic air conditioning system and manual air conditioning system)
      ECM All vehicles
      Center airbag sensor assembly All vehicles
      Power steering ECU All vehicles
      Main body ECU All vehicles
      Combination meter ECU All vehicles
      4WD control ECU Vehicle with 4WD
  3. DTC TABLE BY ECU 

    HINT:

    • In the CAN communication system, CAN communication system DTCs output by the ECU can be displayed by using the Techstream.
    • If CAN communication system DTCs are output, the trouble cannot be determined solely from the DTCs. Perform troubleshooting according to "HOW TO PROCEED WITH TROUBLESHOOTING " .
    1. ABS AND TRACTION ACTUATOR (SKID CONTROL ECU)

      HINT:

      DTC communication uses the CAN communication system.

      DTC CHART

      DTC No. Detection Item
      U0073/94 Control Module Communication Bus OFF
      U0100/65 Lost Communication with ECM / PCM
      U0123/62 Lost Communication with Yaw Rate Sensor Module
      U0124/95 Lost Communication with Lateral Acceleration Sensor Module
      U0126/63 Lost Communication with Steering Angle Sensor Module
    2. POWER STEERING ECU

      HINT:

      DTC communication uses the CAN communication system.

      DTC CHART

      DTC No. Detection Item
      U0073/49 Control Module Communication Bus OFF
      U0105/41 Lost Communication with ECM
      U0121/42 Lost Communication with Anti-lock Brake System (ABS) Control Module
    3. ECM

      HINT:

      DTC communication uses the CAN communication system.

      DTC CHART

      DTC No. Detection Item
      U0122 Lost Communication with Vehicle Dynamic Control Module
      U0129 Lost Communication with Brake System Control Module
    4. AIR CONDITIONING AMPLIFIER

      For vehicle with air conditioning (Automatic air conditioning system and Manual air conditioning system).

      HINT:

      DTC communication uses the CAN communication system.

      DTC CHART

      DTC No. Detection Item
      B1499/99 Multiplex Communication Circuit
    5. COMBINATION METER ECU

      HINT:

      DTC communication uses the CAN communication system.

      DTC CHART

      DTC No. Detection Item
      U0100 Lost Communication with ECM/PCM "A"
      U0129 Lost Communication with Skid Control ECU
    6. 4WD CONTROL ECU

      For vehicle with 4WD only.

      HINT:

      DTC communication uses the CAN communication system.

      DTC CHART

      DTC No. Detection Item
      U0073/86 Control Module Communication Bus OFF
      U0100/85 Lost Communication with ECM / PCM "A"
      U0126/84 Lost Communication with Steering Angle Sensor Module
      U0129/83 Lost Communication with Brake System Control Module
    7. MAIN BODY ECU

      HINT:

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

    8. CENTER AIRBAG SENSOR

      HINT:

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

  4. DTC COMBINATION TABLE 
    DTC COMBINATION

    DTC Detected Communication Stop Mode
    Output from Output DTC ABS AND TRACTION ACTUATOR (SKID CONTROL ECU) COMMUNICATION STOP MODE POWER STEERING ECU COMMUNICATION STOP MODE STEERING ANGLE SENSOR COMMUNICATION STOP MODE YAW RATE SENSOR COMMUNICATION STOP MODE ECM COMMUNICATION STOP MODE
    ABS and Traction Actuator (Skid Control ECU) U0073/94 X X X X
    U0100/65 X X X
    U0123/62 X X X
    U0124/95 X X X
    U0126/63 X X X
    Power Steering ECU U0073/49 X X X X
    U0105/41 X X X X
    U0121/42 X X X X
    ECM U0122 X X X
    U0129 X X X
    Air Conditioning Amplifier B1499/99 X X X X
    Combination Meter ECU U0100 X X X X
    U0129 X X X X
    4WD Control ECU U0073/86 X X X X X
    U0100/85 X X X X
    U0126/84 X X X X
    U0129/83 X X X X
    HINT:
    • ◦: Outputs under condition shown in table above
    • X: Not output
    DTC COMBINATION

    DTC Detected Communication Stop Mode
    Output from Output DTC CENTER AIRBAG ASSEMBLY COMMUNICATION MODE AIR CONDITIONING AMPLIFIER COMMUNICATION STOP MODE COMBINATION METER ECU COMMUNICATION STOP MODE MAIN BODY ECU COMMUNICATION STOP MODE 4WD CONTROL ECU COMMUNICATION STOP MODE
    ABS and Traction Actuator (Skid Control ECU) U0073/94 X X X X X
    U0100/65 X X X X X
    U0123/62 X X X X X
    U0124/95 X X X X X
    U0126/63 X X X X X
    Power Steering ECU U0073/49 X X X X X
    U0105/41 X X X X X
    U0121/42 X X X X X
    ECM U0122 X X X X X
    U0129 X X X X X
    Air Conditioning Amplifier B1499/99 X X X
    Combination Meter ECU U0100 X X X X X
    U0129 X X X X X
    4WD Control ECU U0073/86 X X X X
    U0100/85 X X X X
    U0126/84 X X X X
    U0129/83 X X X X
    HINT:
    1. Perform troubleshooting according to the combination of DTCs output.