Toyota Tundra. Manual — part 265

Fig. 7: Identifying CAN Communication System Components (3 Of 3)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

SYSTEM DIAGRAM

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

Fig. 8: Identifying CAN Communication System Diagram (1 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

Fig. 9: Identifying CAN Communication System Diagram (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

HINT:

The ECM uses the CAN communication system to perform DTC communication instead of the conventional
communication line (SIL).

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

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra

(500 kbps, 250 kbps) and the ability to detect 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 communicating

with each other.

d. The CAN has 2 resistors of 120 ohms which are necessary to communicate with the main wire.

2. DEFINITION OF TERMS

a. Main wire

1. The 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. Branch wire

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

c. Termination circuits

1. The termination circuits is a circuit which converts the communication current of the CAN

communication into the bus voltage. It consists of a resistor and condenser. Two termination
circuits are necessary on a bus.

d. CAN J/C

1. The CAN J/C 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 V bus and MS bus each have termination circuits with 120 ohms x 2 of resistance. High speed

communication at 500 kbps and 250 kbps is possible.

4. ECU OR SENSOR WHICH COMMUNICATE VIA CAN COMMUNICATION SYSTEM

HINT:



*1: w/ Bus Buffer ECU



*2: w/ 4WD



*3: w/ Seat Memory

a. ECM

b. Skid control ECU with actuator

c. Combination meter ECU

d. Center airbag sensor

e. Air conditioning amplifier

f. Steering angle sensor

g. Bus buffer ECU*1

h. 4WD control ECU*2

i. Main body ECU

j. Front power seat ECU and switch LH*3

k. Outer mirror control ECU*3

2009 Toyota Tundra

2009 ACCESSORIES & EQUIPMENT CAN Communication - Tundra