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System Description

WARNING: This page is about a different variant/trim than selected.
  1. BRIEF DESCRIPTION 
    1. The Control Area Network (CAN) is a serial data communication system for real time application. It is a vehicle multiplex communication system which has a high communication speed and the ability to detect malfunctions.
    2. By pairing the CANH and CANL bus wires, the CAN performs communication based on differential voltage.
    3. Many ECUs or sensors installed on the vehicle operate by sharing information and communicating with each other.
    4. The CAN has two resistors of 120 Ω which are necessary to communicate with the main bus wire.
  2. DEFINITION OF TERMS 
    1. Main bus wire
      1. The main bus wire is a wire harness between the two terminating resistors on the bus (communication wire). This is the main bus in the CAN communication system.
    2. Main bus branch wire
      1. The branch wire is a wire harness which diverges from the main bus wire to an ECU or sensor.
    3. Terminating resistors
      1. The termination circuit is a circuit which converts the communication current of CAN communication into the bus voltage. It consists of a resistor and condenser. Two termination circuits are necessary on the bus.
  3. ECUS OR SENSORS WHICH COMMUNICATE THROUGH CAN COMMUNICATION SYSTEM 
    1. V1 Bus
      1. ECM
      2. Power management control ECU
      3. Combination meter
      4. Skid control ECU (Brake booster with master cylinder)
      5. Steering angle sensor
      6. Yaw rate sensor
      7. Power steering ECU
      8. Certification ECU (Smart key ECU)
      9. Main body ECU
    2. V2 Bus
      1. Power management control ECU
      2. Center airbag sensor assembly
      3. Transmission control ECU
    3. Power Management Bus
      1. Power management control ECU
      2. ECM
      3. Skid control ECU (Brake booster with master cylinder)
      4. Air conditioning amplifier
  4. CIRCUIT DESCRIPTION 
    1. The V1 bus, V2 bus and power management bus each have termination circuits with two resistors of 120 Ω. High speed communication at 500 kbps is possible.
  5. TROUBLESHOOTING REMARKS 
    1. DTCs for the CAN communication system can be checked using the Techstream. The DLC3 is connected to the CAN communication system, but no DTCs exist regarding problems in the DLC3 or the DLC3 branch wires. If there is any trouble in the DLC3 or the DLC3 branch wires, ECUs on the CAN network cannot output codes to the Techstream.
    2. Trouble in the CAN buses (communication wires) can be checked by measuring the resistance between terminals of the DLC3. However, an open circuit in a branch wire other than the DLC3 branch wires cannot be checked from the DLC3.
      NOTE:

      Do not insert the tester probes directly into the DLC3. Be sure to use service wires.

  6. DIAGNOSTIC TROUBLE CODE FOR CAN COMMUNICATION SYSTEM 
    1. DTCs for the CAN communication system are as follows: U0073, U0100, U0101, U0103, U0110, U0111, U0123, U0124, U0126, U0129, U0131, U0140, U0142, U0146, U0151, U0155, U0164, U0293, U029A, U0327, U0424, U1002, U1107, U1133, U129A and U129B.
  7. NOTES REGARDING TROUBLESHOOTING 
    1. Trouble in the CAN bus (communication line) can be checked through the DLC3 (except when there is a wire break other than in the branch wire of the DLC3).
      NOTE:

      Do not insert the tester probes directly into the DLC3. Be sure to use service wires.

    2. DTCs regarding the CAN communication system can be checked using the Techstream.
    3. The CAN communication system cannot detect trouble in the branch wires for the DLC3 even though the DLC3 is also connected to the CAN communication system.
  8. HOW TO DISTINGUISH CONNECTOR OF CAN JUNCTION CONNECTOR 
    1. In the CAN communication system, the shape of connectors connected to the CAN junction connector which has an earth terminal is the same. The connectors connected to the CAN junction connector can be distinguished by the colors of the bus wires and the connecting side of the junction connector.

      HINT: 

      See Terminals of ECU for bus wire color or the shape of connecting surface. Refer toTERMINALS OF ECU .