Page 2369 of 4323

I28190
GPS Current longitude/latitude/altitude is determined using the radio wave arrival time from four satellites.
± DIAGNOSTICSNAVIGATION SYSTEM
DI±2167
2361 Author: Date:
2005 SEQUOIA (RM1146U)
(b) Autonomous navigation
This method determines the relative vehicle position based on the running track determined by the
gyro and vehicle speed sensors located in the navigation ECU.
(1) Gyro sensor
Calculates the direction by detecting angular velocity. It is located in the radio and navigation
assy.
(2) Vehicle speed sensor
Used to calculate the vehicle running distance.
(c) GPS navigation (Satellite navigation)
This method detects the absolute vehicle position using radio wave from a GPS satellite.
* GPS satellites were launched by the U.S. Department of Defence for military purposes.
Number of satellitesMeasurementDescription
2 or lessMeasurement impossibleVehicle position cannot be obtained because the number of satellites is not enough.
32±dimensional measure-
ment is possibleVehicle position is obtained based on the current longitude and latitude (This is less precise
than 3±dimensional measurement).
43±dimensional measure-
ment is possibleVehicle position is obtained based on the current longitude, latitude and altitude.
Page 2370 of 4323

I28191
AActual driving route
Driving route on the display
(Route by estimation)
Roads
The system compares the shape of the roads L1,
L2 and L3 to the estimated running track after the
vehicle makes a right turn. At point A, the vehicle
position differs enough from the shape of L1 that
the display switches to the road L2. Start
Map
Matching
I28192
Vy1
Vx1 Vx2
Vy2 Vx1 (Vy1)
Vx2 (Vy2)
Touch±sensitive switch positionThe touch switch detects the voltage ratio
and calculates the position on the screen. Glass
OuterInner
Contact DI±2168
± DIAGNOSTICSNAVIGATION SYSTEM
2362 Author: Date:
2005 SEQUOIA (RM1146U)
(d) Map matching
The current driving route is calculated by autonomous navigation (according to the gyro sensor and
vehicle speed sensor) and GPS navigation. This information is then compared with possible road
shapes from the map data in the map disc and the vehicle position is set onto the most appropriate
road.
(e) Touch switch
Touch switches are touch±sensitive (interactive) switches operated by touching the screen. When a
switch is pressed, the outer glass bends in to contact the inner glass at the pressed position. By doing
this, the voltage ratio is measured and the pressed position is detected.
Page 2371 of 4323

± DIAGNOSTICSNAVIGATION SYSTEM
DI±2169
2363 Author: Date:
2005 SEQUOIA (RM1146U)
4. DVD (Digital Versatile Disc) player outline (for navigation map)
The navigation ECU uses a laser pickup to read the digital signals recorded on a DVD.
HINT:
Do not disassemble any part of the navigation system.
Do not apply oil to the navigation system.
Do not insert anything but a DVD into the navigation system.
CAUTION:
Because the navigation system uses an invisible laser beam, do not look directly at the laser pickup.
Be sure to only operate the navigation as instructed.
5. CD (Compact Disc) player outline
A CD player uses a laser pickup to read digital signals recorded on a CD. By converting the digital signals
to analog, it can play music and other things. In general, CD players can play a 4.7±inch (12 cm) or 3.2±inch
(8 cm) disc.
HINT:
Do not disassemble any part of the CD player.
Do not apply oil to the CD player.
Do not insert anything but a CD into the CD player.
CAUTION:
Because the CD player uses an invisible laser beam, do not look directly at the laser pickup. Be sure
to only operate the player as instructed.
Page 2372 of 4323

I28687
Main AVC±LAN:
(*1, 2) Multi±display Controller
Sub±assy (*1)
Rear Seat Audio
Controller (*2) Radio and Navigation Assy Stereo Component
Amplifier Assy
Sub AVC±LAN:
Disc Player
Controller (*1) Television Display Assy (*1)
*1 w/ RSE
*2: w/ RSA
: AVC±LAN DI±2170
± DIAGNOSTICSNAVIGATION SYSTEM
2364 Author: Date:
2005 SEQUOIA (RM1146U)
6. AVC±LAN Description
(a) What is AVC±LAN?
AVC±LAN, an abbreviation for ºAudio Visual Communication Local Area Networkº, is a united standard
developed by the manufacturers in affiliation with Toyota Motor Corporation. This standard pertains
to audio and visual signals as well as switch and communication signals.
(b) Purpose:
Recently, car audio systems have rapidly developed and the functions vastly changed. The conven-
tional car audio system is being integrated with multi±media interfaces similar to those in navigation
systems. At the same time, customers are demanding higher quality from their audio systems. This
is merely an overview of the standardization background. The specific purposes are as follows.
(1) To solve sound problems, etc. caused by using components of different manufacturers through
signal standardization.
(2) To allow each manufacturer to concentrate on developing products they do best. From this, rea-
sonably priced products can be produced.
Page 2373 of 4323

± DIAGNOSTICSNAVIGATION SYSTEM
DI±2171
2365 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:
If a short to +B or short to ground is detected in the AVC±LAN circuit, communication is interrupted
and the audio system will stop functioning.
If an audio system is equipped with a navigation system, the multi±display unit acts as the master unit.
If the navigation system is not equipped, the audio head unit acts as the master unit instead. If the radio
and navigation assy is equipped, it is the master unit.
The radio and navigation assy provides resistance to make communication possible.
The car audio system with an AVC±LAN circuit has a diagnostic function.
Each component has a specified number (3±digit) called a physical address. Each function has a num-
ber (2±digit) called a logical address.
7. Communication system outline
(a) Components of the audio system communicate with each other via the AVC±LAN.
(b) The master component of the AVC±LAN is a radio and navigation assy with a 60 to 80 W resistor. This
is essential for communication.
(c) If a short circuit or open circuit occurs in the AVC±LAN circuit, communication is interrupted and the
audio system will stop functioning.
8. Diagnostic function outline
(a) The audio system has a diagnostic function (the result is indicated on the master unit).
(b) A 3±digit hexadecimal component code (physical address) is allocated to each component on the
AVC±LAN. Using this code, the component in the diagnostic function can be displayed.
Page 2374 of 4323

DIDBS±01
Vehicle brought into a workshop
1. Diagnostic questioning and symptom confirmation
HINT:
Ask the customer about symptoms and confirm malfunctions.
Fill out the Customer Problem Analysis check sheet.
The screen displays nothing (Go to step 5, proceed
to ºBLACK SCREEN (NO IMAGE APPEARS ON
NAVIGATION/AUDIO SCREEN)º) P. DI±2214 Other symptoms
2. Confirm the system normal condition
P. DI±2162Applicable (This is not a malfunction.)
Not applicable
3. Check the diagnostic trouble codes
HINT:
Even if the malfunction symptom is not confirmed, check the diagnostic trouble codes.
This is because the system stores past diagnostic trouble codes.
Refer to the detailed description on the diagnostic screen, as necessary. A code is outputA code is not output (Go to step 5)
4. Diagnostic trouble code chart.
HINT:
Find the output code on the diagnostic trouble code chart.Output the diagnostic trouble code (Go to step 7)
5. Problem symptoms table
HINT:
If the symptom does not recur and no code is output,
perform the symptom reproduction method.There is an applicable symptom code in the table
(Go to step 7)
There is no applicable
symptom code in the
table
6. Check the ECU terminal arrangement based on the malfunction symptom
7. Circuit inspection and part inspection
8. Recheck the diagnostic trouble code
HINT:
After deleting the DTC, recheck the diagnostic trouble code.
9. Perform confirmation test
ENDItems inside
are titles of pages in this manual,
with the page number in the bottom portion. See
the pages for detailed explanations.
P. DI±2191
P. DI±2214 ± DI±2294 P. DI±2203
P. DI±2184
P. DI±2199
DI±2172
± DIAGNOSTICSNAVIGATION SYSTEM
2366 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO PROCEED WITH TROUBLESHOOTING
Page 2375 of 4323
DIDBT±01
/ /
/ /
I28194
Inspector 's name:
Customer 's NameVIN
Production Date
Licence Plate No.
Odometer Readingkm
mile
Frequency Problem Occurs Always Intermittently ( times a day) Brought in
Date Problem First OccurredDate Vehicle
Problem SymptomDTC Check
1st time trouble code.
2nd time trouble code. RADIO AND NAVIGATION SYSTEM Check Sheet
± DIAGNOSTICSNAVIGATION SYSTEM
DI±2173
2367 Author: Date:
2005 SEQUOIA (RM1146U)
CUSTOMER PROBLEM ANALYSIS CHECK
Page 2376 of 4323

DIDBU±01
30 kHz 300 kHz 3 MHz 30 MHz 300 MHz
LF MF HF VHF
AM FM
Frequency modulation Frequency
Designation
Radio wave
Modulation Amplitude modulation
BE2818
FM (Stereo)
FM (Monaural)
AM
BE2819
Ionosphere Phasing: DI±2174
± DIAGNOSTICSNAVIGATION SYSTEM
2368 Author: Date:
2005 SEQUOIA (RM1146U)
IDENTIFICATION OF NOISE SOURCE
Radio Description
(a) Radio frequency band
Radio Broadcasts use the radio frequency bands shown in the table below.
LF: Low Frequency
MF: Medium Frequency
HF: High Frequency
VHF: Very High Frequency
(b) Service area
The service areas of the AM and FM broadcasts are vast-
ly different. Even if an AM broadcast has clear reception,
an FM broadcast originating in the same location may not
be received at all.
The service area of FM stereo broadcasts is small, and
static as well as interference (noise) easily enters the sig-
nal.
(c) Radio reception problems
HINT:
In addition to static, other problems such as ºphasingº, ºmulti±pathº, and ºfade outº exist. These problems
are not caused by electrical noise, but by the radio signal propagation method itself.
(1) Phasing
The AM frequency band reflects off the earth's iono-
sphere at night. When this occurs, the reflected sig-
nal may interfere with the direct signal sent by the
same transmitter. This phenomenon is known as
ºphasingº.