Toyota Sequoia (2005). Manual - part 491

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DIAGNOSTICS

BODY CONTROL SYSTEM

DI–1759

1953

Illumination circuit

CIRCUIT DESCRIPTION

The body ECU and the back door ECU detect the condition of each door courtesy light switch.
FRONT COURTESY LIGHT SWITCH CONTROL:
The 2 front courtesy light switches are directly connected to the body ECU and back door ECU. If the courte-
sy light switch is turned on (a front door is opened), voltage applied to terminal ILE of the body ECU is
grounded inside the ECU and the step light, front courtesy light, etc. come on.

REAR COURTESY LIGHT SWITCH CONTROL:
The 2 rear courtesy light switches are directly connected to the body ECU and back door ECU via each cour-
tesy light. The rear courtesy light comes on when a rear door is opened.

DID9B–01

I28523

Back Door ECU

Sub J/B No. 3

ILE B11

8

BF1

8

BD2

9

W

W

W

W

J30

J/C

J29

F

M

Instrument Panel J/B

Body ECU

1G

6

1G

5

1M

10

1E

3

1G

13

1G

14

1E

8

1M

6

1J

5

ILE

B7

3

1F

10

1M

7

W

3C

3A

3A

3D

6

6

16

6

I17
Ignition Key
Cylinder Light

1

2

W

R

R

6

R

J48

R

J/C

J49

BC1

L

F

R

D13 Door Courtesy 
Light Rear RH

1

2

D17 Door Courtesy 
Light Switch Rear RH

2

1

W–B

BA1

6

1

2

2

IN1

R

A

A

J21
J/C

R

R

1

B–O

2

1

D8 Diode
(Interior Light No. 1)

BC1

7

R–Y

R–Y

W–B

R

W–B

W–B

R

R

R

W (*1)

W (*2)

W

R

1

2

S8 Step Light

V7 Vanity Light RH

V6 Vanity Light LH

R11 Rear Interior Light

(*4)

(*3)

To Dome Fuse

W–B

W–B

W

G–R

(*2)

(*2)

(*2)

1

2

4

d e

f

g

b c

a

R
(*2)

3

ON

Door

OFF

R

R

DI–1760

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DIAGNOSTICS

BODY CONTROL SYSTEM

1954

WIRING DIAGRAM

(*1): w/o Sliding Roof, RSE and RSA
(*2): w/ Sliding Roof, RSE or RSA
(*3): w/ Sliding Roof w/ RSE or RSA
(*4): w/ Sliding Roof w/o RSE and RSA

I28526

d e

f

g

b c

a

D12 Door Courtesy 
Light Rear LH

D9 Diode
(Interior Light No. 2)

2

1

1

2

W–B

R

BA1

7

R–Y

R–Y

D16 Door Courtesy 
Light Switch Rear LH

1

W–B

(*1) (*2)

O4 O5

3

9

Overhead Module

Personal Light

Rear Interior Light

(*2)

(*1)

(*1)

(*1)

(*1)

ON

Door

OFF

O4

(*1) (*2)

O4 O5

1

13

13

G–R

(*2)

O5

10

A

J8
J/C

IE

W

(*1)

W–B

R

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DIAGNOSTICS

BODY CONTROL SYSTEM

DI–1761

1955

(*1): w/o Sliding Roof, RSE and RSA
(*2): w/ Sliding Roof, RSE or RSA

DI–1762

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DIAGNOSTICS

BODY CONTROL SYSTEM

1956

INSPECTION PROCEDURE

HINT:
When using the hand–held tester, start the inspection from step 1 and when not using the hand–held tester,
start from step 2.

1

Check illumination (interior light) using hand–held tester.

PREPARATION:
(a)

Connect the hand–held tester to the DLC3.

(b)

Turn the ignition switch ON. (Do not start the engine.)

(c)

Turn the light control switch OFF.

CHECK:
According to the display on the tester, perform the ”ACTIVE TEST”.
BODY ECU:

Item

Test Details

Diagnostic Note

ILLUMI OUTPUT

Illuminated entry system ON/OFF

–

OK:

The illumination (interior) lights turn on or off correctly when operating them through the hand–
held tester.

OK

Proceed to next circuit inspection shown in
problem symptoms table (See page 

DI–1686

).

NG

2

Check illumination light (interior light system) (See page 

BE–40

).

NG

Replace defective light.

OK