Page 2193 of 4323
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)
Page 2195 of 4323
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
Page 2201 of 4323
I28476
R6
Light Control
Rheostat AssyRadio Receiver Assy
J/C
Steering Pad Switch
Spiral Cable
Sub±assy From
TAILLIGHT
RelayILL±
GND J/C
ILL+ W±G
GJ39 J40
J39 J40
J39 J40R4
R19 R4R3
R2 W±G
G
G
G A B
A
AAB
ILL±
T12
5
2
10
6 A±1
A±10C9±1
BR±W C9±10(*1)
*1: Separate Type Amplifier
*2: Built±in Type Amplifier(*2) (*1) (*2)
6
4
± DIAGNOSTICSAUDIO SYSTEM
DI±1999
2193 Author: Date:
2005 SEQUOIA (RM1146U)
Illumination circuit
CIRCUIT DESCRIPTION
Power is supplied to the radio receiver panel illumination when the light control switch is in the TAIL or HEAD
position. The body ECU determines the external brightness based on the brightness level detected by the
automatic light control sensor, and then operates the tail relay. Power can also be supplied by operating the
relay.
The intensity of the radio receiver panel illumination can be adjusted by the rheostat switch.
WIRING DIAGRAM
DID9X±01
Page 2260 of 4323
DIDAM±01
I28496
B±O
24R24
Rear Seat Audio
Controller Assy
ACC
+B
17
GND 1228 C
4 3A36
ACC Cut
Relay
B 12 1Sub J/B No.3
3A
ID2 W±R
J/C
L±Y1
2
IA1 26 L±R
L±R
2B3
2C8
2D Engine Room J/B
ECU±BShort Pin
1 Instrument Panel J/B
W±R
AM11
3 2RAD No.2
W 1
P6
ALT
1B
BatteryLG To ECM
GR
RSE
2 2
1Engine Room R/B No.2J37
ID221
IMLG 3A
LG
12
ID2 J38
L±R
2 12
W±LRAD No.1
W±R
W±L 1
2B
3
AM1B
ACC
I18
Ignition SW 1C
1C 1E1F
1J
1LGR
PW±R
GR
W±B 58
4F10
Fusible Link Block DI±2058
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
2252 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT INSPECTION
Power source circuit (Rear seat audio controller)
CIRCUIT DESCRIPTION
This circuit provides the power to the rear seat audio controller.
WIRING DIAGRAM
Page 2312 of 4323
I28486
J/C Sub J/B No.3
R2332 Multi±display Controller Sub±assy
ACC
R2316
+B1
R2329
GND IF3
1
IFC
4 3A36
ACC
Cut Relay
B 1
I18
Ignition SW12
12 3A W±R
W±R
1To ECM
IA126
L±R L±R
2D1
2C8Engine Room J/B
RAD No. 1
ECU±BShort Pin 3
W±L2
W±R 1C
3
1E 1J
W
IL1
IC6AM1
8
F10
FL Block
ALT
54
B
Battery
IM13
LG GR GR
L±Y GR
2 2 Engine Room R/B No. 2
Y
IF33
W±B 3AW±R
1
IF3
22B
P
3
ACCAM1
BB 1 2 W±LB±O
J37 J38
L±YY
RAD No. 2 1Instrument Panel J/B
2
1RSE
2C P DI±2110
± DIAGNOSTICSREAR SEAT ENTERTAINMANT SYSTEM
2304 Author: Date:
2005 SEQUOIA (RM1146U)
Power source circuit (Multi±display controller sub±assy)
CIRCUIT DESCRIPTION
This circuit provides power to the multi±display controller sub±assy.
WIRING DIAGRAM
DIDB5±01
Page 2386 of 4323

DIDC3±01
DI±2184
± DIAGNOSTICSNAVIGATION SYSTEM
2378 Author: Date:
2005 SEQUOIA (RM1146U)
PROBLEM SYMPTOMS TABLE
HINT:
Before performing verification listed in the table below, check the fuse and relay.
Methods used to verify the cause of the problem are listed in order of probability in the verification col-
umn.
Display function
SymptomVerificationSee page
Pressing PWR switch does not turn on system.
1. ºPRESSING POWER SWITCH DOES NOT TURN ON
SYSTEMº
2. Power source circuit (radio and navigation assy)
3. Replace radio and navigation assyDI±2213
DI±2256
±
Black screen (no image appears on navigation and audio screen).
1. ºBLACK SCREEN (NO IMAGE APPEARS ON NAV-
IGATION AND AUDIO SCREEN)º
2. Illumination circuit
3. Power source circuit (radio and navigation assy)
4. Replace radio and navigation assyDI±2214
DI±2260
DI±2256
±
Illumination for panel switch does not come on with TAIL switch
on.
1. ºILLUMINATION FOR PANEL SWITCH DOES NOT
COME ON WITH TAIL SWITCH ONº
2. Illumination circuit
3. Replace radio and navigation assyDI±2216
DI±2260
±
Display does not dim (night screen) with TAIL switch on.
1. ºDISPLAY DOES NOT DIM (NIGHT SCREEN) WITH
TAIL SWITCH ONº
2. Illumination circuit
3. Replace radio and navigation assyDI±2217
DI±2260
±
Power does not turn off (screen remains on).1. Power source circuit (radio and navigation assy)
2. Replace radio and navigation assyDI±2256
±
Panel switch does not function.
1. ºPANEL SWITCH DOES NOT FUNCTIONº
2. Steering pad switch circuit
3. Replace radio and navigation assyDI±2218
DI±2287
±
Touch panel switch does not function.
1. ºTOUCH PANEL SWITCH DOES NOT FUNCTIONº
2. Power source circuit (radio and navigation assy)
3. Replace radio and navigation assyDI±2219
DI±2256
±
Display panel does not open, tilt, or tilts improperly.
1. ºDISPLAY PANEL DOES NOT OPEN, TILT, OR TILTS
IMPROPERLYº
2. Power source circuit (radio and navigation assy)
3. Replace radio and navigation assyDI±2220
DI±2256
±
Screen is distorted.1. Power source circuit (radio and navigation assy)
2. Replace radio and navigation assyDI±2256
±
Screen flicker or color distortion.
1. ºSCREEN FLICKER OR COLOR DISTORTIONº
2. Power source circuit (radio and navigation assy)
3. Replace radio and navigation assyDI±2221
DI±2256
±
Audio function
SymptomVerificationSee page
No sound can be heard from speakers (audio is mute).
1. ºNO SOUND CAN BE HEARD FROM SPEAKERS
(AUDIO IS MUTE)º
2. Speaker circuit
3. AVC±LAN circuit (radio and navigation ± stereo compo-
nent amplifier)
4. Amplifier sound signal circuit
5. Amplifier mute signal circuit
6. Replace stereo component amplifier
7. Replace radio and navigation assyDI±2224
DI±2282
DI±2268
DI±2274
DI±2271
±
±
Page 2458 of 4323
I28474
11 Radio and
Navigation Assy
ACC
1
20
GND GR 1
RAD No. 24 3 A36
ACC Cut Relay
P
3
1 AM1 ACC12 Sub J/B No. 3
3A
W±R
W±R1
IA1 24
L±Y L±Y
2B
3
2C8
2D1 Engine Room J/B
RAD No. 1
ECU±BShort Pin 1J3
1EW±R
1L1
1C6AM12
ALT
B
Battery
IOBRR30 3A
I18
Ignition SWW±LB 212 1
1C 1FGR
GRB C B±O
J37To ECM
J38
Instrument Panel J/B
1 2B
R30
R30 J/C
PW W±R
B 8
54F10
FL Block DI±2256
± DIAGNOSTICSNAVIGATION SYSTEM
2450 Author: Date:
2005 SEQUOIA (RM1146U)
Power source circuit (Radio and navigation assy)
CIRCUIT DESCRIPTION
This circuit provides power to the radio and navigation assy.
WIRING DIAGRAM
DIDDB±01
Page 2460 of 4323
I28475
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
3AM1
ACC W±R
W±L
ALT
B
Battery W±RIL12
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
B
1GR
L±W
L±W
W±R
I18
Ignition SW P
W
8
4
5F10
FL Block DI±2258
± DIAGNOSTICSNAVIGATION SYSTEM
2452 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
DIDDD±01