Toyota Sequoia (2005). Manual - part 471

DID98–01

I28587

From Battery

Driving Position Memory Switch

BODY ECU

Courtesy SW (D)

MM

Remote Control Mirror Switch

RH

Outer 
Mirror LH 
(Retract 
Motor)

M1

M2

MM

M1

DCTY

PCTY

RRCY

RLCY

HCTY

KSW

LSWR

LSWL

PKB

WIG

IG

ACC

BECU

S+B

BDR

ACT+

ACTD

ACT–

M2

MIRB

MIRS

MIRF

M+

MSW

E

B

MF

E2

MR

Door Lock Motor

Front 
LH

Front 
RH

Rear 
LH

Rear 
RH

Courtesy SW (P)

Courtesy SW (RR)

Courtesy SW (RL)

Hood Courtesy SW

Key Unlock Warning SW

Door Unlock Detection 
SW Rear RH

Door Unlock Detection 
SW Rear LH

Parking Brake SW

Battery

AM1

ALT

ACC

IG1

Ignition Switch

WSH

ECU–IG

RAD No. 2

ECU–B

DOOR No. 2

SECURITY 
HORN

AM1

–

DIAGNOSTICS

BODY CONTROL SYSTEM

DI–1679

1873

SYSTEM DIAGRAM

I28588

BEAN

BODY ECU

Hi Beam Indicator

Driver Door ECU

A/C ECU

Sliding Roof 
Control ECU

MPX1

MPX2

MPX3

HIND

HRLY

H–ON

DIM

HEAD

TAIL

A

HF

HI

FOG

Combination Meter

From 
Battery

HEAD

MAIN

Headlight

DRL (*1)

Headlight

DRL No. 4

H–LP(*2)

DRL

H–LP(*2)

Headlight

Headlight

H–LP(*1)

H–LP(*1)

H–LP(*1)

H–LP(*1)

DIMMER

(*2)

(*2)

Combination Switch

Light Control 
Switch

Dimmer 
Switch

Fog Light 
Switch

DRL 
Resister

*1: w/ DRL 
*2: w/o DRL

DI–1680

–

DIAGNOSTICS

BODY CONTROL SYSTEM

1874

I28734

BODY ECU

Back Door 
Power Window SW

Rear Wiper 
and 
Washer 
Switch

Rear Washer 
Motor

Theft Deterrent Horn

Light 
Control 
Sensor

Wireless 
Door Lock 
Receiver

ECU–B

From 
Battery

DLC3

From 
Battery

POWER MAIN

Power 
Window SW 
(RR)

Power 
Window 
Motor (RR)

PWR 
No. 3

PWR 
No. 2

Power 
Window SW 
(RL)

Power 
Window 
Motor (RL)

From 
Battery

From 
Battery

DOME

HORN

Interior Light

HORN

Vehicle Horn

Combination Meter

Security Indicator

Horn Switch

Glass 
Breakage 
Sensor ECU

Wireless Buzzer

ECU–B

HTR

PWS

BUP

BDN

RWLS

RWC1

RWW

SH

TRCY

RRU

RRD

RLU

RLD

ILE

CLTB

CLTS

CLTE

HR

RDA

PRG

GND1

IND

HORN

BZR

OBD2

DOP

Microphone

From
Battery

–

DIAGNOSTICS

BODY CONTROL SYSTEM

DI–1681

1875

DI1OD–22

Customer Problem Analysis

Vehicle Brought to Workshop

Problem Symptom Confirmation

Symptom Simulation

Symptom does not
occur

Circuit Inspection

Identification of Problem

Repair

Confirmation Test

End

Titles inside

are titles of pages in this

manual, with the page number indicated in
the bottom portion. See the indicated pages
for detailed explanations.

1

2

3

6

5

8

P. 

IN–24

P. 

DI–1683

P. 

DI–1700

 – 

DI–1774

Symptom
occurs

Step 4, 6, 8: Diagnostic steps permitting the use of the hand–held tester.

7

Problem Symptoms Table

P. 

DI–1686

P. 

DI–1904

Multiplex communication system inspection *

4

*: Confirm that there is no trouble by DTC check.

DI–1682

–

DIAGNOSTICS

BODY CONTROL SYSTEM

1876

HOW TO PROCEED WITH TROUBLESHOOTING

HINT:
This ECU is connected to the multiplex communication system. Therefore, be sure to check that there is no
troubles in the multiplex communication system before performing the troubleshooting.