TOYOTA SEQUOIA 2001 Service Repair Manual

I28755
Stereo Component Amplifier Assy:
MUTE
S10
I28606
Radio Receiver Assy
Wire Harness View:
MUTE
R4
I28752
Stereo Component Amplifier Assy:
MUTE
S10
± DIAGNOSTICSAUDIO SYSTEM
DI±2009
2203 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect stereo component amplifier assy.
PREPARATION:
Make sure that the stereo component amplifier assy connector
is connected.
CHECK:
Measure the voltage according to the value in the table below.
OK:
Symbol
(Tester connection)ConditionSpecification
MUTE (S10±1) ±
Body groundTurn ignition switch to
ACC, Audio system is
playing "Changing mode
Above 3.5 V " Below 1 V
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI±1967).
NG
2 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)ConditionSpecified condition
MUTE (R4±7) ±
MUTE (S10±1)AlwaysBelow 1 W
MUTE (R4±7) ±
Body groundAlways10 kW or higher
NG Repair or replace harness or connector.

I28738
R4 Wire Harness View:
MUTE
DI±2010
± DIAGNOSTICSAUDIO SYSTEM
2204 Author: Date:
2005 SEQUOIA (RM1146U)
OK
3 Inspect radio receiver assy.
PREPARATION:
Reconnect the radio receiver assy connector.
CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:
Symbol
(Tester connection)ConditionSpecified condition
MUTE (R4±7) ±
Body groundIgnition switch ONAbove 3.5 V
OK Replace stereo component amplifier assy.
NG
Replace radio receiver assy.

I28505
WRadio Receiver Assy
G 429
8
R B
R4L+
L± Stereo Component
Amplifier Assy
R+
R±
GND 19
18
10 3
S10
5
Shielded L+
L± R+
R±S10
S10
S10
S106R4
R4
R4
R4 SGND
± DIAGNOSTICSAUDIO SYSTEM
DI±2011
2205 Author: Date:
2005 SEQUOIA (RM1146U)
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
± DIAGNOSTICSAUDIO SYSTEM
2206 Author: Date:
2005 SEQUOIA (RM1146U)
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 W
L± (R4±19) ± L± (S10±2)Below 1 W
R+ (R4±8) ± R+ (S10±5)Below 1 W
R± (R4±18) ± R± (S10±4)Below 1 W
L+ (R4±9) ± Body ground10 kW or higher
L± (R4±19) ± Body ground10 kW or higher
R+ (R4±8) ± Body ground10 kW or higher
R± (R4±18) ± Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Proceed to next circuit inspection shown in problem symptoms table (See page DI±1967).

± DIAGNOSTICSAUDIO SYSTEM
DI±2013
2207 Author: Date:
2005 SEQUOIA (RM1146U)
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 RHII2
J/C
BC1
BA1 R10
Rear Door
Speaker RH
R9
Rear Door
Speaker LHJ/C BC1
BA1II2
II2
II2
J49 J48
J49 J48
J34 J33
J34 J33IB1
IB1
IB1S9
S9
S9
S9
S9
S9
S9
S9
S9
S9
S9FL±
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 31
2 4
23
4 1
2
3 4
15
4
6
7
2
1
10
9
11 12
11 12 2 1
2 1I
C
HB
KE
LF V
P
G
L±W LRV
P
G L±W
R Y
L LGR Y
L LG V
P
R
WR
WR
W
Y B
Y B
Y B Separate Type Amplifier: DI±2014
± DIAGNOSTICSAUDIO SYSTEM
2208 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

I28504
FL±
FR+
RR+ RL+ FL+
FR±
RR± RL± IB1
54
VP
V P
IB1R2
R3R2
R3
R3
R3 R2
R22
6
L LG
L LG
5
2 6 T12
Tweeter LH
312 4
1
3
1 9 10
II2
II2 V PL R
312 4T13
Tweeter RH 1
2
1
2
B Y
R WB Y
R WB Y
R W 1 2
1 2BA1
BC1BA1
BC1Junction
Connector
Junction
Connector J34 J33
J49 J48 11
12
11
12J34 J33
J49J48B L
KF
E
H
IC F16
Front Door
Speaker LH
F17
Front Door
Speaker RH
R9
Rear Door
Speaker LH
R10
Rear Door
Speaker RHRadio Receiver Assy Built±in Type Amplifier:
± DIAGNOSTICSAUDIO SYSTEM
DI±2015
2209 Author: Date:
2005 SEQUOIA (RM1146U)

DI±2016
± DIAGNOSTICSAUDIO SYSTEM
2210 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check apparatus.
CHECK:
Choose the apparatus to be inspected.
ApparatusGo to step
Separate type amplifierA
Built±in type amplifierB
B Go to step 6.
A

I36938I28293
Stereo Component Amplifier Assy:
RR+
FL+RL+
WFL+
RR±FL±
RL± WFL± WFR±
WFR+
FR± FR+
S9
I28355
Rear Speaker Connector Front View:
R10
R9
I28757
Front Door Speaker Assy and Woofer
Connector Front View:
F14
F15
I28758
Tweeter Connector Front View:
T12
T13
± DIAGNOSTICSAUDIO SYSTEM
DI±2017
2211 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check harness and connector (Stereo component amplifier assy ± Speaker
assy).
PREPARATION:
Disconnect the connectors from the radio receiver assy and
speakers.
CHECK:
Measure the resistance between the speaker and the stereo
component amplifier to check for an open circuit in the wire har-
ness.
OK:
Below 1 W
CHECK:
Measure the resistance between each speaker and body
ground to check for a short circuit in wire harness.
OK:
10 kW or higher
HINT:
Refer to the wiring diagram for connection of each terminal.
NG Repair or replace harness or connector.
OK

I28759
Front Door Speaker Assy and Woofer
Connector Front View:
F14
F15
DI±2018
± DIAGNOSTICSAUDIO SYSTEM
2212 Author: Date:
2005 SEQUOIA (RM1146U)
3 Inspect front door speaker and woofer.
CHECK:
Measure the resistance according to the value(s) in the table
below.
NOTICE:
The speaker should not be removed for checking.
OK:
Tester connectionSpecified condition
1 ± 2Approx. 3.15 W
3 ± 4Approx. 2.78 W
NG Replace front door speaker and woofer.
OK
4 Inspect tweeter.
CHECK:
Check that malfunction disappears when another tweeter in good condition is installed.
OK:
Malfunction disappears.
HINT:

Connect all the connectors to the speakers.

When there is a possibility that either right or left front speaker is defective, inspect by interchanging
the right one and the left one.
OK Replace tweeter.
NG