BRIEF DESCRIPTION
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 detect malfunctions.
By pairing the CANH and CANL bus lines, the CAN performs communication based on differential voltages.
Many ECUs (sensors) installed on the vehicle operate by sharing information and communicating with each other.
The CAN has two 120 Ω resistors which are necessary to communicate with the main wire.
DEFINITION OF TERMS
Main wire
The main wire is a wire harness between the two terminus circuits on the bus (communication line). This is the main bus in the CAN communication system.
Branch wire
A branch wire is a wire harness which diverges from the main wire to an ECU or sensor.
Terminus circuit
A terminus circuit is a circuit which converts the communication current of the CAN communication into the bus voltage. It consists of a resistor and condenser. Two terminus circuits are necessary on a bus.
CAN junction connector
A CAN junction connector is a junction designed for CAN communication.
ECUS OR SENSORS WHICH COMMUNICATE VIA CAN COMMUNICATION SYSTEM
Brake actuator assembly (Skid control ECU)
Steering column assembly (Power steering ECU)
Spiral cable sub-assembly (Steering sensor)
Yaw rate sensor
ECM
Center airbag sensor assembly
Air conditioning amplifier assembly
Combination meter Assembly (combination meter ECU)
Main body ECU
Certification ECU*1
Power management control ECU*2
Power source control ECU*3
Engine stop and start ECU*4
*1: w/ Entry and Start System
*2: for 1KR-FE and 1NR-FE
*3: for 1ND-TV
*4: w/ Stop and Start System
DIAGNOSTIC CODES FOR CAN COMMUNICATION SYSTEM
DTCs for the CAN communication system are as follows: U0073, U0100, U0101, U0121, U0123, U0124, U0126, U0129, U0131, U0140, U0142, U0151, U0155, U0164, U0327, U1002 and U1133.
NOTES REGARDING TROUBLESHOOTING
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 connect the tester directly to the DLC3 connector. Be sure to use a service wire.
DTCs relating to the CAN communication system can be checked using the intelligent tester.
The CAN communication system cannot detect trouble in the DLC3 branch line even though the DLC3 is also connected to the CAN communication system.