CAN Communication System

NETWORKING: CAN COMMUNICATION SYSTEM: SYSTEM DIAGRAM

1. SYSTEM DIAGRAM









* *1: w/ Smart Key System

* *2: for Automatic Transaxle

2. V1 BUS









3. POWER MANAGEMENT BUS (w/ Smart Key System)





4. POWERTRAIN BUS (for Automatic Transaxle)










SYSTEM DESCRIPTION


1. BRIEF DESCRIPTION

(a) The CAN (Controller Area Network) is a serial data communication system for real-time application. It is a vehicle multiplex communication system which has a high communication speed (500 kbps) and the ability to detection malfunctions.

(b) By pairing the CANH and CANL bus lines, the CAN performs communication based on differential voltages.

(c) Many ECUs (sensors) installed on the vehicle operate by sharing information and communication with each other.

(d) The CAN has 2 resistors of 120 Ohms which are necessary to communicate using the main wire.

2. DEFINITION OF TERMS

(a) CAN main wire

(1) The CAN main wire is a wire harness between the 2 termination circuits on the bus (communication line). This is the main bus in the CAN communication system.

(b) CAN branch wire

(1) The CAN branch wire is a wire harness which diverges from the main wire to an ECU or sensor.

(c) Termination circuit

(1) The termination circuit is a circuit which converts the communication current of the CAN communication into the bus voltage. It consists of a resistor and capacitor. 2 termination circuits are necessary on a bus.

(d) CAN junction connector

(1) The CAN junction connector is designed so that it can be used with CAN communication which has a termination circuit and CAN communication which does not have a termination circuit.

3. CIRCUIT DESCRIPTION

(a) The V1 bus, power management bus and powertrain bus each have termination circuits with resistance of 120 Ohms X 2. High speed communication at 500 kbps is possible.

4. ECUS OR SENSORS WHICH COMMUNICATE VIA CAN COMMUNICATION SYSTEM

(a) ECM

(b) Power source control ECU*1

(c) Main body ECU (multiplex network body ECU)

(d) Brake actuator assembly (skid control ECU)

(e) Yaw rate sensor assembly

(f) DLC3

(g) Spiral with sensor cable sub-assembly (steering angle sensor)

(h) Power steering ECU assembly

(i) Certification ECU (smart key ECU assembly)*1

(j) Center airbag sensor assembly

(k) Combination meter assembly

(l) Air conditioning amplifier assembly

(m) Transmission control ECU assembly*2

* *1: w/ Smart Key System

* *2: for Automatic Transaxle

5. DIAGNOSTIC CODES FOR CAN COMMUNICATION SYSTEM

(a) DTCs for the CAN communication system are as follows: U0073, U0100, U0101, U0123, U0124, U0126, U0129, U0131, U0142, U0151 and U0155.

6. NOTES REGARDING TROUBLESHOOTING

(a) Trouble in the CAN bus (communication line) can be checked through the DLC3 (except when there is a wire break in the CAN branch wire of the DLC3).

(b) DTCs regarding the CAN communication system can be checked using the Techstream.

(c) The CAN communication system cannot detect trouble in the branch line of the DLC3 even though the DLC3 is also connected to the CAN communication system.

7. HOW TO DISTINGUISH CAN JUNCTION CONNECTOR CONNECTORS

(a) In the CAN communication system, the shape of all connectors connected to the CAN junction connector is the same.

The connectors connected to the CAN junction connector can be distinguished by the colors of the bus line and the connecting side of the connector.

HINT
See "Terminals of ECU" CAN Communication System for bus line color or the type of connecting surface.