Toyota Sequoia (2005). Manual - part 554

I28505

W

Radio Receiver Assy

G

4

2

9

8

R

B

R4

L+

L–

Stereo Component 
Amplifier Assy

R+

R–

GND

19

18

10

3

S10

5

Shielded

L+

L–

R+

R–

S10

S10

S10

S10

6

R4

R4

R4

R4

SGND

–

DIAGNOSTICS

AUDIO SYSTEM

DI–2011

2205

Sound signal circuit

CIRCUIT DESCRIPTION

The radio receiver assy sends a sound signal to the stereo component amplifier assy through this circuit.
The sound signal that has been sent is amplified by the stereo component amplifier assy, and then sent to
the speakers.
If there is an open or short in the circuit, sound cannot be heard from the speakers even if there is no malfunc-
tion in the stereo component amplifier assy or the speakers.

WIRING DIAGRAM

DID9Z–01

I28739

Radio Receiver Assy 
Wire Harness View:

R4

L–

L+

R+

R–

I28752

Stereo Component Amplifier Assy 
Wire Harness View:

L+

R–

L–

R+

S10

DI–2012

–

DIAGNOSTICS

AUDIO SYSTEM

2206

INSPECTION PROCEDURE

1

Check harness and connector (Radio receiver assy – Stereo component amplifi-
er assy).

PREPARATION:
Disconnect the radio receiver assy and stereo component am-
plifier assy connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:

Symbol (Tester connection)

Specified condition

L+ (R4–9) – L+ (S10–3)

Below 1 

Ω

L– (R4–19) – L– (S10–2)

Below 1 

Ω

R+ (R4–8) – R+ (S10–5)

Below 1 

Ω

R– (R4–18) – R– (S10–4)

Below 1 

Ω

L+ (R4–9) – Body ground

10 k

Ω 

or higher

L– (R4–19) – Body ground

10 k

Ω 

or higher

R+ (R4–8) – Body ground

10 k

Ω 

or higher

R– (R4–18) – Body ground

10 k

Ω 

or higher

NG

Repair or replace harness or connector.

OK

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

DI–1967

).

–

DIAGNOSTICS

AUDIO SYSTEM

DI–2013

2207

Speaker circuit

CIRCUIT DESCRIPTION

The sound signal that has been amplified by the stereo component amplifier is sent to the speakers from
the stereo component amplifier through this circuit.
If there is a short in this circuit, the stereo component amplifier assy (built–in amp) detects it and stops output
to the speakers.
Thus sound cannot be heard from the speakers even if there is no malfunction in the stereo component am-
plifier assy (built–in amp) or the speakers.

DIDA0–01

I28503

Stereo Component 
Amplifier Assy

IB1

S9

T12 
Tweeter RH

F14 Front Door Speaker 
and Woofer LH

F15 Front Door Speaker 
and Woofer LH

T13 
Tweeter RH

II2

J/C

BC1

BA1

R10 
Rear Door 
Speaker RH

R9 
Rear Door 
Speaker LH

J/C

BC1

BA1

II2

II2

II2

J49

J48

J49

J48

J34

J33

J34

J33

IB1

IB1

IB1

S9

S9

S9

S9

S9

S9

S9

S9

S9

S9

S9

FL–

WFL+

WFR–

FR+

RR+

RL+

FL+

WFL–

WFR+

FR–

RR–

RL–

11

2

6

17

18

7

3

5

12

14

4

13

2

3

4

1

3

1

2

4

2

3

4

1

2

3

4

1

5

4

6

7

2

1

10

9

11

12

11

12

2

1

2

1

I

C

H

B

K

E

L

F

V

P

G

L–W

L

R

V

P

G

L–W

R

Y

L

LG

R

Y

L

LG

V

P

R

W

R

W

R

W

Y

B

Y

B

Y

B

Separate Type Amplifier:

DI–2014

–

DIAGNOSTICS

AUDIO SYSTEM

2208

WIRING DIAGRAM