Lexus ES300 (2002 year). Manual - part 87

BODY ELECTRICAL

BODY ELECTRICAL – BODY ELECTRICAL SYSTEM CONTROL

BE-2

211BE01

Front Passenger 
Door ECU

Rear RH Door ECU

BEAN

Theft Deterrent ECU

Body ECU

Local Communication

Driver Door ECU

Rear LH Door ECU

BODY ELECTRICAL SYSTEM CONTROL

MULTIPLEX COMMUNICATION SYSTEM

1. General

 A multiplex communication system has been adopted for body electrical system control and to achieve

a slimmer wiring harnesses configuration.

 BEAN (Body Electronics Area Network) has been adopted between the body ECU, driver door ECU, front

passenger door ECU, theft deterrent ECU.

 The local protocol unidirectional communication has been adopted between the body ECU, rear RH door

ECU, rear LH door ECU.

 A customized body electronics system, which improves the malfunction diagnostic function, enables the

functions to be changed according to customer needs, and reduce the types of parts, has been adopted.

 System Diagram 



BODY ELECTRICAL – BODY ELECTRICAL SYSTEM CONTROL

BE-3

211BE02

Body ECU

Theft Deterrent ECU

Front Passenger Door ECU

Rear RH Door ECU

Rear LH Door ECU

Driver Door ECU

 Layout of Main Component 



BODY ELECTRICAL – BODY ELECTRICAL SYSTEM CONTROL

BE-4

208BE03

208BE51

Battery

Switch

ECU

On

On

Off

Serial Data 
Communication

ECU

Light

Motor

Heater

Solenoid

Battery

Switch

Light

Motor

Heater

Solenoid

Multiplex Communication System

Conventional System

2. System Outline

In the conventional system, electrical loads such as motors and lights were directly connected by wire harness
to their switches which controlled their operation. However, in the multiplex communication system, the wire
harness is replaced by serial data communication by the ECU, to provide functions similar to the conventional
system, through a single serial communication bus. With this system, even when multiple tasks demand addi-
tional switches and electrical loads, communication among ECUs can be implemented through the serial
communication bus only, resulting in the only reduction in wire harnesses.

 Conceptual Drawing of Multiplex Communication System 



BODY ELECTRICAL – ACCESSORIES

BE-62

211BE40

(2)

(5)

(4)

(3)

(1)

Lumber Support Switch 
(Driver Seat)

Power Seat Switch

211BE41

Battery

Power Seat Switch

Slide

Front
Vertical

Rear
Vertical

Reclining

Lumber
Support

Switch

(Driver Seat)

Lumber
Support

POWER SEAT

 The power seat has been adopted for driver and front passenger seats on all models as standard equipment.
 The following features are all for power functions.

Power Adjustment Function

Stroke

(1)

Fore-and-After Slide

mm (in.)

240 (9.45)

(2)

Reclining

degrees

48

(3)

Front Vertical

mm (in.)

22 (0.87)

(4)

Rear Vertical

mm (in.)

45 (1.77)

(5)

Lumber Support (Driver Seat)

mm (in.)

48 (1.89)

 System Diagram