Toyota Sequoia (2005). Manual - part 549

I28498

11

Radio Receiver Assy

ACC+B

1

R4

20

GND

GR

1

RAD No. 2

4

3

A36 
ACC Cut Relay

P

3

1

AM1

ACC

12

Sub J/B No. 3

3A

W–R

W–R

1

IA1

24

L–Y

L–Y

2B

3

2C

8

2D

1

Engine Room J/B

RAD No. 1

ECU–B

Short Pin

1J

3

1E

W–R

1L

1

1C

6

AM1

2

ALT

5

B

Battery

IO

BR

Separate Type Amplifier:

R4

R4

3A

I18 
Ignition SW

W–L

B

2

12

1

1C

1F

GR

GR

B

C

B–O

J37

To ECM

J38

Instrument Panel J/B

1

2

BU+B

W

8

4

F10
Fusible Link Block

J/C

–

DIAGNOSTICS

AUDIO SYSTEM

DI–1991

2185

I28739

Separate Type Amplifier 
Wire Harness View:

GND

ACC+B

BU+B

R4

I28743

Built–in Type Amplifier 
Wire Harness View:

GND

ACC+B

BU+B

R2

DI–1992

–

DIAGNOSTICS

AUDIO SYSTEM

2186

INSPECTION PROCEDURE

1

Inspect radio receiver assy.

PREPARATION:
Disconnect the radio receiver assy connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:

Symbol 

(Tester connection)

Condition

Specified condition

GND (R2–7, R4–20) –

Body ground

Always

Below 1 

Ω

CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:

Symbol 

(Tester connection)

Condition

Specified condition

BU+B (R2–4, R4–1) –

GND (R2–7, R4–20)

Always

10 to 14 V

ACC+B (R2–3, R4–11) –

GND (R2–7, R4–11)

Ignition SW ACC

10 to 14 V

NG

Repair or replace harness or connector 
(Radio receiver assy – battery or body ground).

OK

Proceed to next circuit inspection shown in problem symptoms table or diagnostic trouble code
chart (See page 

DI–1967

 or 

DI–1979

).

I28500

GR

1

4

3

A36 
ACC Cut Relay

12

Sub J/B No. 3

3A

W–R

1

2

3A

GR

B

C

B–O

J37

To ECM

J38

RAD No. 2

3

1

6

AM1

2

12

1

Instrument Panel J/B

1

2

P

3

AM1

ACC

W–R

W–L

ALT

5

B

Battery

W–R

ILI

2

L–W

2A

2C

8

2D

1

Engine Room J/B

RAD No. 3

ECU–B

Short Pin

3

B

B

B

B

J11

J10

J11

L–W

IO

BR

BR

S10

S9

S9

S9

S9

12

10

15

16

1

ACC

B2+

B+

GND

E

Stereo Component 
Amplifier Assy

1J

1E

1L

1C

1C

1F

J/C

J/C

GR

8

4

F10
Fusible Link Block

W

L–W

L–W

I18
Ignition SW

–

DIAGNOSTICS

AUDIO SYSTEM

DI–1993

2187

Power source circuit (Stereo component amplifier assy)

CIRCUIT DESCRIPTION

This circuit provides power to the stereo component amplifier assy.

WIRING DIAGRAM

DID9V–01

I28324

GND

ACC

B2+

E

B+

S9

S10

DI–1994

–

DIAGNOSTICS

AUDIO SYSTEM

2188

INSPECTION PROCEDURE

1

Inspect stereo component amplifier assy (B+, B2+, ACC, GND, E).

PREPARATION:
Disconnect the stereo component amplifier assy connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:

Symbol 

(Tester connection)

Condition

Specified condition

E (S9–16) – Body ground

Always

Below 1 

Ω

GND (S9–15) – 

Body ground

Always

Below 1 

Ω

CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:

Symbol 

(Tester connection)

Condition

Specified condition

B+ (S9–1) – GND (S9–15)

Always

10 to 14 V

B2+ (S9–10) – 

GND (S9–15)

Always

10 to 14 V

ACC (S10–12) – 

GND (S9–15)

Ignition SW ACC

10 to 14 V

NG

Repair or replace harness or connector (Stereo
component amplifier assy – battery or body
ground).

OK

Proceed to next circuit inspection shown in problem symptoms table or diagnostic trouble code
chart (See page 

DI–1967

 or 

DI–1979

).