radio TOYOTA SEQUOIA 2001 Service Repair Manual

B04770
IN±18
± INTRODUCTIONFOR ALL OF VEHICLES
18 Author: Date:
2005 SEQUOIA (RM1146U)
(4) Check that the VSC TRAC warning light blinks.
(5) After the measurement, remove the SST and re-
start the engine. At this time, make sure that the
VSC TRAC warning light is off.
(b) Notice in VSC operation.
(1) Removal and reinstallation of VSC±related compo-
nents may cause misadjustment of them. Do not re-
move or reinstall them unless necessary.
(2) When conducting VSC±related operations, do not
fail to make sure that the preparation and the finish-
ing of the operation are all performed in accordance
with the direction in this text.
3. FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER
CAUTION:
If a large amount of unburned gasoline flows into the converter, it may overheat and create a fire haz-
ard. To prevent this, observe the following precautions and explain them to your customer.
(a) Use only unleaded gasoline.
(b) Avoid prolonged idling.
Avoid running the engine at idle speed for more than 20 minutes.
(c) Avoid spark jump test.
(1) Perform spark jump test only when absolutely necessary. Perform this test as rapidly as possible.
(2) While testing, never race the engine.
(d) Avoid prolonged engine compression measurement.
Engine compression tests must be done as rapidly as possible.
(e) Do not run engine when fuel tank is nearly empty.
This may cause the engine to misfire and create an extra load on the converter.
(f) Avoid coasting with ignition turned off.
(g) Do not dispose of used catalyst along with parts contaminated with gasoline or oil.
4. IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM
For vehicles with mobile communication systems such as two±way radios and cellular telephones, observe
the following precautions.
(1) Install the antenna as far as possible away from the ECU and sensors of the vehicle's electronic
system.
(2) Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the ve-
hicle's electronic systems. For details about ECU and sensor locations, refer to the section on
the applicable component.
(3) Do not wind the antenna feeder together with the other wiring as much as possible, also avoid
running the antenna feeder parallel with other wire harness.
(4) Check that the antenna and feeder are correctly adjusted.
(5) Do not install powerful mobile communication system.

DIDJV±01
F19126
Combination meter assy
(Vehicle speed signal)
Tire pressure monitor receiver assyCombination meter assy
(Tire pressure warning lamp) Tire
Pressure
Monitor
ECU
: Radio signal
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (FR LH)
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (FR RH)
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (RR LH)
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (RR RH)
Tire Pressure Sensor
(Tire pressure monitor valve
sub±assy) (SPARE)
DLC3
Tire pressure warning reset switch
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±799
993 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM

DIDJW±01
F19887
Tire Pressure Monitor Valve Sub±assy
Tire Pressure
Warning Reset
Switch
Tire Pressure
Monitor ECU
Meter
DLC3
Tire Pressure Monitor Valve Sub±assyTire Pressure Monitor Receiver Assy
DI±800
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
994 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DESCRIPTION
1. DESCRIPTION OF SYSTEM
(a) A tire pressure monitor valve sub±assy equipped with a tire pressure sensor and a transmitter and is
installed in a tire wheel assy. The sensor measures the tire pressure and the measured value and
transmitter ID are transmitted to the tire pressure monitor receiver assy on the body as radio waves
and then sent to the tire pressure monitor ECU from the tire pressure monitor receiver. If the transmitter
ID has already been registered, the ECU compares the measured air pressure value with the standard
value. When the value is less than the standard value registered in the tire pressure monitor ECU, the
warning lamp on the combination meter comes on.

To address the differences in the air pressure settings by the type of tires, or the differences in
pressure between the front and rear tires, a tire pressure warning reset switch has been newly
adopted.

Along with the adoption of the tire pressure warning reset switch, the warning operation has been
changed.

TPWS transmitters with different bending angles as the tire pressure monitor valve sub±assy
have been provided for steel wheels with center ornaments. (They are not interchangeable with
aluminum wheels or steel wheels with full wheel caps.)
2. WHEN TIRE PRESSURE WARNING LAMP IS LIT
(a) When the warning lamp does not go off, or when it comes on during driving, check tire pressure. If the
warning lamp is lit even though the tire pressure is correctly adjusted, the tire could be punctured.
(b) Under the following conditions, the system may not function properly.

The areas, facilities or devices that use similar radio frequencies are located in the vicinity of the
vehicle.

A radio device of similar frequency is used in the vehicle.

A lot of snow or ice is stuck to the vehicle, especially onto the wheels and around the wheel
houses.

The battery of the sensor has been depleted.

The tires without tire pressure monitor valve sub±assy are used.

Tire chains are used.

± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±801
995 Author: Date:
2005 SEQUOIA (RM1146U)

When the spare tire is not within the receivable range of the electric wave, a signal may not be
received because spare tires are fixed. Accordingly, the system may not function properly. If
there is a possibility that the TPWS system does not receive a signal from the spare tire, rotate
the tire 90°.
HINT:

If any other wheels than the specified ones are used, the system may not function properly because
the radio waves are differently transmitted from the tire pressure sensor.

Depending on the tire type, the system may not function properly even though the specified wheels
are used.
(c) The average use life of the grommet of the tire pressure monitor valve sub±assy is approximately 5
years, at which time it must be replaced.
(d) After removing and installing the ECU or a sensor, output a diagnosis code and check that it is a normal
code.
3. FUNCTION OF COMPONENTS
ComponentsFunction
Tire pressure monitor valve sub±assy
Combined as a single unit with a disc wheel air valve, it measures tire pressure and
temperature and transmits an ID number for measurement value and identification.
Built±in the battery.
Tire pressure monitor receiver assyReceives and transmits a necessary signal from the transmitter to the tire pressure
monitor ECU.
Tire pressure monitor ECU
Receives the signal from the receiver and identifies it as vehicle's own signal. If the
measurement value is equal to or lower than the specified value, it transmits a sig-
nal so that the air pressure warning lamp on the combination meter comes on.
Tire pressure warning lampLocated in the combination meter, it informs the driver of lowered tire air pressure
and system failure.
Tire pressure warning reset switchEnters the initialization mode for tire or wheel replacement, or tire rotation
4. TIRE PRESSURE WARNING RESET SWITCH

By operating the tire pressure warning reset switch, the tire pressure monitor ECU can be set to issue
a warning at an inflation pressure that corresponds to the type of tires. Therefore, the dealer must set
the warning threshold to the proper value in order to comply with the local regulations.

Operate the tire pressure warning reset switch only after the inflation pressures of all 5 tires (including
the spare) have been adjusted on the vehicle.

To initialize the system, press and hold the tire pressure warning reset switch for 3 seconds or longer
with the ignition switch ON. After the system has been initialized, the warning lamp blinks 3 times (1
second ON, 1 second OFF).

During initialization, the tire pressure monitor valve sub±assy measures the inflation pressure of the
tires, and registers the signals that are transmitted into the tire pressure monitor ECU at a frequency
of one per minute. The initialization process is completed when the signals from the 5 tires have been
received.

The initialization process is canceled if the ignition switch is turned OFF during initialization. To initialize
again, the tire pressure warning reset switch must be pressed again. For this reason, once the tire pres-
sure warning reset switch has been pressed, turning OFF the ignition switch is not recommended for
a minimum of 20 minutes.

F19171
Tire Pressure
Monitor ECU Tire Pressure Monitor
Valve Sub±assy Front LH
Tire Pressure Monitor
Valve Sub±assy Rear LH Tire Pressure Monitor
Valve Sub±assy Front RH
Tire Pressure Monitor
Valve Sub±assy Rear RHJ29A
H
J30 3
4
5 BD2
5
1
4 +5V
RDA
GNDL
V
BR±R T19
Tire Pressure
Monitor Receiver
BD2
BD2L
VL
RF5V
RDA
GND2
Tire Pressure Monitor
Valve Sub±assy SpareJ29C J29B
I
J30
J
J30 BR±RBR±R J/C
T178
T177
T1716 V
: Radio Signal
± DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
DI±835
1029 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT DESCRIPTION
The tire pressure monitor valve sub±assy constantly sends radio waves to the tire pressure monitor receiver
assy. If the battery for the tire pressure monitor valve sub±assy is depleted, or if the tire pressure monitor
receiver assy is defective or comes off, the DTC will be output. DTCs C2121/21 to C2125/25 can only be
deleted by the tester. DTCs C2181/81 to C2185/85 can be deleted when the transmitter sends a force trans-
mission signal or the test mode ends. DTCs C2181/81 to C2185/85 are output only in the test mode.
DTC No.DTC Detecting ConditionTrouble Area
C2121/21
C2122/22
C2123/23
C2124/24
C2125/25A DTC is detected when the ECU receives no signals for
51 minutes or more, the vehicle speed is 5 mph (8 km/h) or
higher, and the ECU receives no signals for 12 minutes or
more.
Tire pressure monitor receiver assy

Each tire pressure monitor valve sub±assy

Tire pressure monitor ECU

Wire harness
C2181/81
C2182/82
C2183/83
C2184/84
C2185/85
Malfunction in the transmitting/receiving circuit

Tire pressure monitor receiver assy

Each tire pressure monitor valve sub±assy

Tire pressure monitor ECU

Wire harness
HINT:
It is necessary to perform the procedure to identify the tire pressure monitor valve sub±assy that is malfunc-
tioning because it cannot be identified by the output DTC.
WIRING DIAGRAM

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)

I28193
AVC±LANStereo Component
Amplifier Assy Radio Receiver Assy
(Resistor 60 to 80 W)
Example : DI±1960
± DIAGNOSTICSAUDIO SYSTEM
2154 Author: Date:
2005 SEQUOIA (RM1146U)
4. OUTLINE OF AVC±LAN
(a) What is AVC±LAN?
AVC±LAN is the abbreviation for Audio Visual Communication±Local Area Network. This is a unified
standard co±developed by 6 audio manufacturers associated with Toyota Motor Corporation.
The unified standard includes signals, such as audio, visual and signals for switch indication and com-
munication.
(b) Objectives
Recently development in car audio systems has been rapid and functions have been changed drasti-
cally. The conventional system has been switched to a multi±media type such as a navigation system.
At the same time customers wants to upgrade their audio systems. This is the factor that lies behind
this standardization.
The concrete objectives are explained below.
(1) When products by different manufacturers were combined together, malfunctions such as sound
failure occurred. This problem can be solved by standardization of signals.
(2) Various types of after market products are available.
(3) In general, a new product developed by a particular manufacturer could not be used due to a
lack of compatibility with other manufacturer's products. By developing this new standard, users
can enjoy a range of compatible products from different manufacturers.
HINT:

When +B short or GND short is detected in the AVC±LAN circuit, communication stops, and the audio
system will not function.

When the audio system is not equipped with a navigation system, the audio head unit is the master
unit. When the audio system is equipped with a navigation system, the multi±display is the master unit.

The radio receiver assy is equipped with a resistor (60 to 80 W) for communication.

All car audio systems using an AVC±LAN circuit have a diagnostic function.

Each unit has its own specified number called a physical address (three±digit number). Numbers are
also allotted to each function, which are called logical addresses (two±digit number).
5. COMMUNICATION SYSTEM
(a) Components in the audio system communicate with each other through the AVC±LAN. (Radio receiver
with CD changer control function)
(b) When a short circuit or circuit breakdown occurs in the AVC±LAN circuit, the audio system does not
operate normally due to the communication cutoff.

I28736
Main AVC±LAN:
(*1)
(*2, 3)Multi±display
Controller (*2)
Rear Seat Audio
Controller (*3) Radio
Receiver Assy Stereo
Component
Amplifier
Sub AVC±LAN:
(*2)
(*2)
Disc
Player
Controller
(*2) Television
Display Assy (*2)
*1: Separate Type Amplifier
*2: w/ RSE System
*3: w/ RSA System
± DIAGNOSTICSAUDIO SYSTEM
DI±1961
2155 Author: Date:
2005 SEQUOIA (RM1146U)
6. DIAGNOSTIC FUNCTION
(a) The audio system has diagnostic function (The diagnostic result is displayed on the LCD of the radio
receiver assy). (Radio receiver with CD changer control function)
(b) The component code (physical address), or three±digit number (in hexadecimal) is set for each com-
ponent comprising AVC±LAN.
(c) The logical address, or two±digit number (in hexadecimal) is set for each function and component unit
in each component.