2001 TOYOTA SEQUOIA audio

IN0IG±04
BO4111
Negative Cable
± INTRODUCTIONFOR ALL OF VEHICLES
IN±9
9 Author: Date:
2005 SEQUOIA (RM1146U)
FOR ALL OF VEHICLES
PRECAUTION
1. FOR VEHICLES EQUIPPED WITH SRS AIRBAG AND
SEAT BELT PRETENSIONER
(a) The SEQUOIA is equipped with an SRS (Supplemental
Restraint System), such as the driver airbag, front pas-
senger airbag, side airbag assembly, curtain shield airbag
assembly and seat belt pretensioner.
Failure to carry out service operations in the correct se-
quence could cause the supplemental restraint system to
unexpectedly deploy during servicing, possibly leading to
a serious accident.
Further, if a mistake is made in servicing the supplemental
restraint system, it is possible the SRS may fail to operate
when required. Before servicing (including removal or
installation of parts, inspection or replacement), be sure
to read the following items carefully, then follow the cor-
rect procedure described in this manual.
(b) GENERAL NOTICE
(1) Malfunction symptoms of the supplemental re-
straint system are difficult to confirm, so the diag-
nostic trouble codes become the most important
source of information when troubleshooting. When
troubleshooting the supplemental restraint system,
always inspect the diagnostic trouble codes before
disconnecting the battery (See page DI±1118).
(2) Work must be started after 90 seconds from the
time the ignition switch is turned to the ºLOCKº posi-
tion and the negative (±) terminal cable is discon-
nected from the battery.
(The supplemental restraint system is equipped
with a back±up power source because if work is
started within 90 seconds of disconnecting the neg-
ative (±) terminal cable from the battery, the SRS
may deploy.)
When the negative (±) terminal cable is discon-
nected from the battery, memory of the clock and
audio systems will be cancelled. So before starting
work, make a record of the contents memorized in
each memory system. When work is finished, reset
the clock and audio systems as before. To avoid
erasing the memory of each memory system, never
use a back±up power supply from another battery.

IN01T±18
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±23
23 Author: Date:
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the SEQUOIA. In general, the ECU controlled system
is considered to be a very intricate system requiring a high level of technical knowledge and expert skill to
troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, troubleshooting of
these systems is not complex. If you have adequate understanding of the system and a basic knowledge
of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem. This
manual is designed through emphasis of the above standpoint to help service technicians perform accurate
and effective troubleshooting, and is compiled for the following major ECU controlled systems:
The troubleshooting procedure and how to make use of it are described on the following pages.
SystemPage
1. EngineDI±1
2. Automatic TransmissionDI±515
3. Air Suspension Control SystemDI±695
4. Tire Pressure Warning SystemDI±796
5. ABS with EBD & BA & TRAC & VSC SystemDI±891
6. Can Communication SystemDI±1060
7. Supplemental Restraint SystemDI±1118
8. Power Seat Control System w/ Driving Position MemoryDI±1501
9. Cruise Control SystemDI±1536
10.Engine Immobilizer SystemDI±1570
11. Combination Meter SystemDI±1601
12.Sliding Roof SystemDI±1661
13.Body Control SystemDI±1678
14.Driver Door Control SystemDI±1778
15.Passenger Door Control SystemDI±1814
16.Back Door Control SystemDI±1850
17.Multiplex Communication SystemDI±1887
18.Audio SystemDI±1955
19.Rear Seat Audio SystemDI±2044
20.Rear Seat Entertainment SystemDI±2078
21.Navigation SystemDI±2159
22.Air Conditioning SystemDI±2297
FOR USING OBD II SCAN TOOL OR TOYOTA HAND±HELD TESTER

Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should
be read thoroughly.

If the scan tool or tester cannot communicate with ECU controlled systems when you have connected
the cable of the scan tool or tester to DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Bus
line) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outline in the Tester Operator's
Manual.

IN±26± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
26 Author: Date:
2005 SEQUOIA (RM1146U)
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the SEQUOIA fulfills various functions. The first function is the Diagnostic Trouble
Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the ECU memory
at the time of occurrence, to be output by the technician during troubleshooting. Another function is the Input
Signal Check which checks if the signals from various switches are sent to the ECU correctly.
By using these check functions, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the SEQUOIA.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Diagnostic Test
Mode (Active Test)
1. Engine(with Check
Mode)
2. Automatic Transmission(with Check
Mode)
3. Air Suspension Control System(with Check
Mode)
4. Tire Pressure Warning System
5. ABS with EBD & BA & TRAC & VSC System
6. Can Communication System
7. Supplemental Restraint System(with Check
Mode)
8. Power Seat Control System w/ Driving Position Memory
9. Cruise Control System
10.Engine Immobilizer System
11. Combination Meter System
12.Sliding Roof System
13.Body Control System
14.Driver Door Control System
15.Passenger Door Control System
16.Back Door Control System
17.Multiplex Communication System
18.Audio System
19.Rear Seat Audio System
20.Rear Seat Entertainment System
21.Air Conditioning System
In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diag-
nostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition,
it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic
trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes
should be checked before and after the symptom confirmation to determine the current conditions, as shown
in the table on the next page. If this is not done, it may, depending on the case, result in unnecessary trouble-
shooting for normally operating systems, thus making it more difficult to locate the problem, or in repairs not
pertinent to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic
trouble code check.

A23548
ECM
E4
STAR ACCR
AM28
ED I18
Ignition SWB B
B±W 1C9
620
42 P
1
B±W
B 1
J2
J/C 1
17
B±O
2D
ALTE7 J38
1FGR
W4
ED2 IA1
S3 F10
Fusible
Link Block4
W±R
B±L
Battery 5B
ST 3A
1
StarterST Relay 5
B
12 3
Instrument Panel J/B
12
Engine Room J/B
2C
5 Sub J/B No. 4
P 3A 12A36
ACC CUT Relay
to Audio
J37J/C
C
GR
4 GR
N B±R
B±R
J/C BD
J51 J52B±R
STSW
E6 IG4B
Engine Room R/B No.2
2 B
2 2
2
2 2 B±RB±R RAD No.2
1C
1C
1C
1J 1J1J
1L
1E 3
5
W±L W±R
W±R
2C
2E1
3B±R
3
B1
B±W
W±B 6
A 1
2 3 58
3
J5
J/C 1
1W±B 128 B±R
W±RJ51 BE6 11
STA W±R
21
3
S2W±R4A
4B 19
9 Sub J/B No.4 GR
P1
Park/Neutral
Position SW
AM1ACC
AM2
ST2
ECU±B
SHORT PIN
B 7
B 2AM1
1
STA8
IA5
± DIAGNOSTICSENGINE
DI±299
493 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

DID9J±01
± DIAGNOSTICSAUDIO SYSTEM
DI±1955
2149 Author: Date:
2005 SEQUOIA (RM1146U)
AUDIO SYSTEM
PRECAUTION
NOTICE:
When disconnect the battery terminal, initialize the following systems after the terminal is recon-
nected.
System NameSee Page
Back Door Power Window Control SystemBE±77

DID9K±01
I27726
Radio Receiver Assy
Rear Door Speaker Tweeter
Rear Door Speaker Front Door Speaker (*1)
Front Door Speaker and
Woofer (*2)Steering Pad
Switch
Instrument Panel J/B

RAD NO. 2 Fuse

ECU±B Fuse

AM1 FuseEngine Room J/B

RAD NO. 1 Fuse

RAD NO. 3 Fuse
Ignition Switch
Disc Player
Controller
(*3)
Stereo
Component
AmplifierMulti±display
Controller (*3)
VTR
Terminal
(*3)Headphone
Terminal
(*3, *4)
Television Display Assy (*3)
Rear Seat Audio
Controller Assy (*4)
Radio Sub
Antenna*1: Built±in Type Amplifier
*2: Separate Type Amplifier
*3: w/ RSE System
*4: w/ RSA System Radio Main Antenna
DI±1956
± DIAGNOSTICSAUDIO SYSTEM
2150 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

DID9L±01
I28760
Built±in Type Amplifier:
Radio
Receiver
Assy
Steering Pad SwitchSpeakers Sound Signal Operation
Signal
Sound Signal
± DIAGNOSTICSAUDIO SYSTEM
DI±1957
2151 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM

I28735
Separate Type Amplifier:
Steering Pad Switch
AVC±LAN Speakers
Sound SignalOperation
Signal
Radio
Receiver
Assy Stereo
Component
Amplifier
Assy
Multi±display
Controller
Assy (*1)
Rear Seat Audio
Controller (*2)
*1: w/ Rear Seat Entertainment System
*2: w/Rear Seat Audio System
Display Signal DI±1958
± DIAGNOSTICSAUDIO SYSTEM
2152 Author: Date:
2005 SEQUOIA (RM1146U)