TOYOTA SEQUOIA 2001 Service Repair Manual

± DIAGNOSTICSAUDIO SYSTEM
DI±1989
2183 Author: Date:
2005 SEQUOIA (RM1146U)

*2: When 210 sec. has passed after pulling out the power supply connector of the master component
with the ignition switch in ACC or ON, this code is stored.

*3: This code may be stored when the engine key is turned 1 min. again after engine start.

*4: This code may be stored when the engine key is turned again after engine start.

I28499
Built±in Type Amplifier:
Radio Receiver Assy A36
ACC Cut Relay Sub J/B No. 3
Instrument Panel J/B
Engine Room J/BTo ECM
Battery
IFR2
R2
R2 12
3A1
3A
1
4 3 W±R
2
GR B C B±O
J37 J38
IA124
L±Y L±Y GR
2B
2C8
2D1 RAD No. 1
ECU±BShort Pin 3
W±R
BRB RAD No. 2
3
1 6AM1 212 1
P
31ALT
5
B
I18
Ignition SWW±L1 2
AACC+B
GND BU+B 4 3
7 W±R
1J
1E
1L 1C1C1F
ACCAM1
GR
8
F10
Fusible Link Block
4 WJ/C
J12
Junction
Connector DI±1990
± DIAGNOSTICSAUDIO SYSTEM
2184 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT INSPECTION
Power source circuit (Radio receiver assy)
CIRCUIT DESCRIPTION
This circuit provides power to the radio receiver assy.
WIRING DIAGRAM
DID9U±01

I28498
11 Radio Receiver Assy
ACC+B
1
R420
GND GR 1
RAD No. 24 3 A36
ACC Cut Relay
P
31AM1 ACC12 Sub J/B No. 3
3AW±R
W±R1
IA124
L±Y L±Y
2B
3
2C8
2D1 Engine Room J/B
RAD No. 1
ECU±BShort Pin 1J3
1E
W±R
1L1
1C6AM12
ALT
5
B
Battery
IOBR Separate Type Amplifier:
R4 R4 3A
I18
Ignition SWW±LB 212 1
1C 1FGR
GRB C B±O
J37To ECM
J38
Instrument Panel J/B
1 2BU+B
W
8
4 F10
Fusible Link BlockJ/C
± DIAGNOSTICSAUDIO SYSTEM
DI±1991
2185 Author: Date:
2005 SEQUOIA (RM1146U)

I28739
Separate Type Amplifier
Wire Harness View:
GND ACC+B
BU+B
R4
I28743
Built±in Type Amplifier
Wire Harness View:
GND
ACC+BBU+B R2
DI±1992
± DIAGNOSTICSAUDIO SYSTEM
2186 Author: Date:
2005 SEQUOIA (RM1146U)
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)ConditionSpecified condition
GND (R2±7, R4±20) ±
Body groundAlwaysBelow 1 W
CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:
Symbol
(Tester connection)ConditionSpecified condition
BU+B (R2±4, R4±1) ±
GND (R2±7, R4±20)Always10 to 14 V
ACC+B (R2±3, R4±11) ±
GND (R2±7, R4±11)Ignition SW ACC10 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
3AW±R 1
2 3A
GRB C B±O
J37To ECM
J38
RAD No. 2
3
1 6AM1 212 1Instrument Panel J/B
1 2
P
3
AM1
ACC W±R
W±LALT
5
B
Battery W±RILI2
L±W
2A
2C8
2D1 Engine Room J/B
RAD No. 3
ECU±BShort Pin 3
B B
BBJ11
J10 J11 L±W
IOBR
BRS10
S9
S9S9
S9 12
10
15
161ACC
B2+
B+
GND
E Stereo Component
Amplifier Assy
1J 1E
1L 1C 1C 1FJ/C
J/C
GR
8
4 F10
Fusible Link Block WL±W L±W
I18
Ignition SW
± DIAGNOSTICSAUDIO SYSTEM
DI±1993
2187 Author: Date:
2005 SEQUOIA (RM1146U)
Power source circuit (Stereo component amplifier assy)
CIRCUIT DESCRIPTION
This circuit provides power to the stereo component amplifier assy.
WIRING DIAGRAM
DID9V±01

I28324GND ACC
B2+ EB+
S9S10
DI±1994
± DIAGNOSTICSAUDIO SYSTEM
2188 Author: Date:
2005 SEQUOIA (RM1146U)
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)ConditionSpecified condition
E (S9±16) ± Body groundAlwaysBelow 1 W
GND (S9±15) ±
Body groundAlwaysBelow 1 W
CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:
Symbol
(Tester connection)ConditionSpecified condition
B+ (S9±1) ± GND (S9±15)Always10 to 14 V
B2+ (S9±10) ±
GND (S9±15)Always10 to 14 V
ACC (S10±12) ±
GND (S9±15)Ignition SW ACC10 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).

I28501
Steering
Pad SwitchSpiral Cable
Sub±assyRadio Receiver Assy
SW2
GND SW1 R19
EAUAU2
R19
R19 AU1
EAUAU2
AU1C9±11 GR±R
LG±R
BR±W C9±12
C9±10 A±11
A±12
A±108
7
6
± DIAGNOSTICSAUDIO SYSTEM
DI±1995
2189 Author: Date:
2005 SEQUOIA (RM1146U)
Steering pad switch circuit
CIRCUIT DESCRIPTION
This circuit sends an operation signal from the steering pad switch to the radio receiver assy.
If there is an open in the circuit, the audio system cannot be operated by the steering pad switch.
If there is a short in the circuit, the same condition as when the switch is continuously depressed occurs.
Therefore, not only the steering pad switch cannot operate the radio receiver assy, but also the radio receiver
assy itself cannot function.
WIRING DIAGRAM
DID9W±01

I28741
SW2
SW1 GND
R19
Separate Type Amplifier
Wire Harness View:
I28745
R19
SW2
SW1 GND
Built±in Type Amplifier
Wire Harness View:
DI±1996
± DIAGNOSTICSAUDIO SYSTEM
2190 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
NOTICE:
The vehicle is equipped with SRS (Supplemental Restraint System) such as airbags. Before servic-
ing (including removal or installation of parts), be sure to read the precautionary notice for the sup-
plemental restraint system (see page RS±1).
1 Inspect steering pad switch 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)ConditionSpecified condition
SW1 (R19±7) ±
GND (R19±6)No switch is pushedApprox. 100 kW
SW1 (R19±7) ±
GND (R19±6)SEEK+ switch: pushApprox. 0 W
SW1 (R19±7) ±
GND (R19±6)SEEK± switch: pushApprox. 0.3 kW
SW1 (R19±7) ±
GND (R19±6)VOL+ switch: pushApprox. 1 kW
SW1 (R19±7) ±
GND (R19±6)VOL± switch: pushApprox. 3.2 kW
SW2 (R19±8) ±
GND (R19±6)No switch is pushedApprox. 100 kW
SW2 (R19±8) ±
GND (R19±6)MODE switch: pushApprox. 0 W
NG Go to step 2.
OK
Proceed to next circuit inspection shown in problem symptoms table (See page DI±1967).

I28724
EAUAU2AU1
Connector Front View:
± DIAGNOSTICSAUDIO SYSTEM
DI±1997
2191 Author: Date:
2005 SEQUOIA (RM1146U)
2 Inspect steering pad switch assy.
PREPARATION:
Disconnect the steering pad switch assy connector.
CHECK:
Measure the resistance according to the value(s) in the table below.
OK:
Symbol (Tester connection)ConditionSpecified condition
AU1 (A±12) ± EAU (A±10)No switch is pushedApprox. 100 kW
AU1 (A±12) ± EAU (A±10)SEEK+ switch: pushApprox. 0 W
AU1 (A±12) ± EAU (A±10)SEEK± switch: pushApprox. 0.3 kW
AU1 (A±12) ± EAU (A±10)VOL+ switch: pushApprox. 1 kW
AU1 (A±12) ± EAU (A±10)VOL± switch: pushApprox. 3.2 kW
AU2 (A±11) ± EAU (A±10)No switch is pushedApprox. 100 kW
AU2 (A±11) ± EAU (A±10)MODE switch: pushApprox. 0 W
NG Replace steering pad switch assy.
OK

I28340
Steering Pad Switch Assy Side:
EAUAU2
AU1
Vehicle Side:
EAUAU2
AU1
C9
A
DI±1998
± DIAGNOSTICSAUDIO SYSTEM
2192 Author: Date:
2005 SEQUOIA (RM1146U)
3 Inspect spiral cable sub±assy.
PREPARATION:
Disconnect the spiral cable sub±assy connector.
CHECK:
Measure the resistance according to the values in the table be-
low.
OK:
Symbol (Tester connection)Specified condition
EAU (A±10) ± EAU (A±10)Below 1 W
AU1 (A±12) ± AU1 (A±12)Below 1 W
AU2 (A±11) ± AU2 (A±11)Below 1 W
NG Replace spiral cable sub±assy.
OK
Repair or replace harness or connector (Radio receiver assy ± spiral cable).