TOYOTA SEQUOIA 2001 Service Repair Manual

I28337
R24
+B
ACC
GND
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
DI±2059
2253 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect rear seat audio controller (+B, ACC, GND).
PREPARATION:
Disconnect the rear seat audio controller connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Symbol
(Tester connection)ConditionSpecified condition
GND (R24±17) ±
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 (R24±12) ±
GND (R24±17)Always10 to 14 V
ACC (R24±24) ±
GND (R24±17)Ignition SW ACC10 to 14 V
NG Repair or replace harness or connector.
OK

DI±2060
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
2254 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check problem symptoms table.
CHECK:
Check the problem symptoms table.
RESULT:
All possible suspected areas have been inspected.Go to step A
Possible suspected areas still exist.Go to step B
B Proceed to next circuit inspection shown in
problem symptoms table (See page DI±2050).
A
Replace rear seat audio controller.

I28599I28773
w/o Navigation:
Radio Receiver Assy
Rear Seat Audio Controller
R19
Stereo Component Amplifier AssyTX± TX+
S10 ID2
LG
LG
V
P L 9
10
5
R41522
R24
23
TX1± TX1+
TX± TX+27 26
TX± TX+ 20
19 R19
R4LGID2 R24
S10
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
DI±2061
2255 Author: Date:
2005 SEQUOIA (RM1146U)
AVC±LAN circuit
CIRCUIT DESCRIPTION
Each unit of the rear seat audio system connected to the AVC±LAN (communication bus) transfers the signal
of each switch by communication.
When a short to +B or short to ground occurs in this AVC± LAN, the audio system will not function normally
as communication is discontinued.
WIRING DIAGRAM
DIDAN±01

I28599I28773
w/ Navigation:
Radio and Navigation AssyRear Seat Audio Controller
R27
Stereo Component Amplifier AssyTX± TX+
S10 ID2
LG
LG
V
P L 9
10
5
1522
R24
23
TX± TX+
ATX± ATX+27 26
TX± TX+ 20
19 R30LGID2 R24
S10 R30 R27
DI±2062
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
2256 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Service check mode (Rear seat audio controller).
CHECK:
Start the diagnosis system and read the check result for the rear seat audio controller (See page DI±1974,
DI±2191).
RESULT:
ºNCONº is displayed or result is not displayed (w/ naviga-
tion)Go to step A
ºNCONº is displayed or result is not displayed (w/o naviga-
tion)Go to step B
ºNCONº is displayed or result is not displayed (DSP AMP)Go to step C
ºGOODº is displayedGo to step D
B Go to step 3.
C Go to step 4.
D Replace radio and navigation assy or radio re-
ceiver assy.
A

I28299TX±
Radio and Navigation Assy
Wire Harness View:
TX+R27
I28337TX+
R24
TX±
Rear Seat Audio Controller
Wire Harness View:
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
DI±2063
2257 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check harness and connector (Rear seat audio controller ± Radio and navigation
assy).
PREPARATION:
Disconnect the R24 and R27 connectors.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Symbol
(Tester connection)ConditionSpecified condition
TX+ (R24±22) ±
TX+ (R27±9)AlwaysBelow 1 W
TX± (R24±23) ±
TX± (R27±10)AlwaysBelow 1 W
TX+ (R24±22) ± Body
groundAlways10 kW or higher
TX± (R24±23) ± Body
groundAlways10 kW or higher
NG Repair or replace harness or connector.
OK
Replace rear seat audio controller.

I28605
TX1+
R19
Radio Receiver Assy
Wire Harness View:
TX1±
I28337TX+
R24
TX±
Rear Seat Audio Controller
Wire Harness View:
DI±2064
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
2258 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check harness and connector (Rear seat audio controller ± Radio receiver assy).
PREPARATION:
Disconnect the R19 and R24 connectors.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Symbol
(Tester connection)ConditionSpecified condition
TX+ (R24±22) ±
TX1+ (R19±9)AlwaysBelow 1 W
TX± (R24±23) ±
TX1± (R19±10)AlwaysBelow 1 W
TX+ (R24±22) ± Body
groundAlways10 kW or higher
TX± (R24±23) ± Body
groundAlways10 kW or higher
NG Repair or replace harness or connector.
OK
Replace rear seat audio controller.

I28606
Radio Receiver Assy
Wire Harness View:
TX±
TX+
R4
I28292TX+
Radio and Navigation Assy:
TX±R30
I28752
Stereo Component Amplifier Assy :
S10
TX± TX+
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
DI±2065
2259 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check harness and connector (Radio receiver assy / radio and navigation assy ±
Stereo component amplifier assy).
PREPARATION:
Disconnect the radio receiver assy or radio and navigation assy
and stereo component amplifier assy connectors.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Radio Receiver Assy:
Symbol
(Tester connection)ConditionSpecified condition
TX+ (R4±5) ±
TX+ (S10±20)AlwaysBelow 1 W
TX± (R4±15) ±
TX± (S10±19)AlwaysBelow 1 W
TX+ (R4±5) ± Body
groundAlways10 kW or higher
TX± (R4±15) ± Body
groundAlways10 kW or higher
Radio And Navigation Assy:
Symbol
(Tester connection)ConditionSpecified condition
TX+ (R30±5) ±
TX+ (S10±20)AlwaysBelow 1 W
TX± (R30±15) ±
TX± (S10±19)AlwaysBelow 1 W
TX+ (R30±5) ± Body
groundAlways10 kW or higher
TX± (R30±15) ± Body
groundAlways10 kW or higher
NG Repair or replace harness or connector.
OK
Replace rear seat audio controller.

I28377
w/o Navigation System:
R19
Radio Receiver AssyRear Seat Audio Controller
RMUT
ID2 19
R2411
RMU11
LG R±W
I28377
w/ Navigation System:
R27
Radio and Navigation AssyRear Seat Audio Controller
RMUT
ID2 19
R2411
RMUT11
LG R±W DI±2066
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
2260 Author: Date:
2005 SEQUOIA (RM1146U)
Mute signal circuit (to rear seat audio controller)
CIRCUIT DESCRIPTION
This circuit sends the signal to the rear seat audio controller to mute the noise. Because of that, the noise
produced by changing the sound source ceases.
If there is an open in the circuit, noise can be heard from the speaker when changing the sound source.
If there is a short in the circuit, even though the rear seat audio controller is normal, no sound or only extreme-
ly small sound can be produced.
WIRING DIAGRAM
DIDAO±01

I28336
RMUT
R24Wire Harness View:
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
DI±2067
2261 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect rear seat audio controller.
PREPARATION:
Make sure that the rear seat audio controller connector is con-
nected.
CHECK:
Measure the voltage according to the value in the table below.
OK:
Symbol
(Tester connection)ConditionSpecification
RMUT (R24±11) ±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±2050).
NG
2 Check system.
CHECK:
Check whether the vehicle is equipped with a navigation system or not.
RESULT:
w/o NavigationGo to step A
w/ NavigationGo to step B
B Go to step 5.
A

I28337
R24
RMUT
Rear Seat Audio Controller
Wire Harness View:
I28605
RMU
R19
Radio Receiver Assy
Wire Harness View:
DI±2068
± DIAGNOSTICSREAR SEAT AUDIO SYSTEM
2262 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check harness and connector (Radio receiver assy ± Rear seat audio controller).
PREPARATION:
Disconnect the R19 and R24 connectors.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Symbol
(Tester connection)ConditionSpecified condition
RMUT (R24±11) ±
RMU (R19±19)AlwaysBelow 1 W
RMUT (R24±11) ± Body
groundAlways10 kW or higher
NG Repair or replace harness or connector.
OK
4 Replace rear seat audio controller.
CHECK:
Replace the rear seat audio controller and check if it operates normally.
OK:
The function returns to normal.
OK Normal operation.
NG
Replace radio receiver assy.