TOYOTA SEQUOIA 2001 Service Repair Manual

± DIAGNOSTICSAUDIO SYSTEM
DI±2019
2213 Author: Date:
2005 SEQUOIA (RM1146U)
5 Inspect rear speaker assy.
CHECK:
Measure the resistance between the terminals of the speaker.
NOTICE:
The speaker should not be removed for checking.
OK:
2.6 ± 0.2 W
NG Replace rear speaker assy.
OK
Proceed to next circuit inspection shown in problem symptoms table (See page DI±1967).

I28754
Radio Receiver Assy
Wire Harness View:
FL±
FL+
FR+ RR±
RL±
RR+RL+
R2R3
FR±
I28355
Front Door Speaker Assy and Rear
Speaker Connector Front View:
F17
F16
R9
R10
I28758
Tweeter Assy Connector Front View:
T12
T13
DI±2020
± DIAGNOSTICSAUDIO SYSTEM
2214 Author: Date:
2005 SEQUOIA (RM1146U)
6 Check harness and connector (Radio receiver assy ± Speaker assy).
PREPARATION:
Disconnect the connectors from the radio receiver assy and
speakers.
CHECK:
Measure the resistance between the speaker and the radio re-
ceiver assy to check for an open circuit in the wire harness.
OK:
Below 1 W
CHECK:
Measure the resistance between each speaker and body
ground to check for a short circuit in wire harness.
OK:
10 kW or higher
HINT:
Refer to the wiring diagram for connection of each terminal.
NG Repair or replace harness or connector.
OK

± DIAGNOSTICSAUDIO SYSTEM
DI±2021
2215 Author: Date:
2005 SEQUOIA (RM1146U)
7 Inspect front door speaker assy.
CHECK:
Measure the resistance between the terminals of the speaker.
NOTICE:
The speaker should not be removed for checking.
OK:
Approximately 4 W
NG Replace front door speaker assy.
OK
8 Inspect tweeter assy.
CHECK:
Check that malfunction disappears when another tweeter in good condition is installed.
OK:
Malfunction disappears.
HINT:

Connect all the connectors to the speakers.

When there is a possibility that either right or left front speaker is defective, inspect by interchanging
the right one and the left one.
OK Replace tweeter.
NG

DI±2022
± DIAGNOSTICSAUDIO SYSTEM
2216 Author: Date:
2005 SEQUOIA (RM1146U)
9 Inspect rear speaker assy.
CHECK:
Measure the resistance between the terminals of the speaker.
NOTICE:
The speaker should not be removed for checking.
OK:
Approximately 4 W
NG Replace rear speaker assy.
OK
Proceed to next circuit inspection shown in problem symptoms table (See page DI±1967).

I28506
Stereo Component
Amplifier Assy
Radio Receiver Assy
TX+
S10
R4 V
P
TX±
S10 R4TX+
TX± 20 5
19 15
± DIAGNOSTICSAUDIO SYSTEM
DI±2023
2217 Author: Date:
2005 SEQUOIA (RM1146U)
AVC±LAN circuit (Radio receiver assy ± stereo component ampli-
fier)
CIRCUIT DESCRIPTION
Each unit of the 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.
In this AVC±LAN, the radio receiver assy becomes the master of the communication, and the radio receiver
assy has resistance necessary for communication.
WIRING DIAGRAM
DIDA1±01

I28765
Radio Receiver Assy
Wire Harness View:
TX±
TX+
R4
DI±2024
± DIAGNOSTICSAUDIO SYSTEM
2218 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect radio receiver assy.
PREPARATION:
Disconnect the radio receiver assy connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Symbol
(Tester connection)ConditionSpecified condition
TX+(R4±5) ± TX± (R4±15)Always60 to 80 W
NG Replace radio receiver assy.
OK

I28739
Radio Receiver Assy
Wire Harness View:
TX±
TX+
R4
I28752
Stereo Component Amplifier Assy:
TX± TX+
S10
± DIAGNOSTICSAUDIO SYSTEM
DI±2025
2219 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check harness and connector (Radio receiver assy ± Stereo component amplifi-
er assy).
PREPARATION:
Disconnect the stereo component amplifier assy connector.
CHECK:
Measure the resistance according to the values in the table be-
low.
OK:
Symbol (Tester connection)Specified condition
TX+ (R4±5) ± TX+ (S10±20)Below 1 W
TX± (R4±15) ± TX± (S10±19)Below 1 W
TX+ (R4±5) ± Body ground10 kW or higher
TX± (R4±15) ± Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Proceed to next circuit inspection shown on problem symptoms table or diagnostic trouble code
chart (See page DI±1967 or DI±1979).

DI±2026
± DIAGNOSTICSAUDIO SYSTEM
2220 Author: Date:
2005 SEQUOIA (RM1146U)
Sound quality is bad in all modes (Volume is too low)
INSPECTION PROCEDURE
1 Adjust sound quality.
CHECK:
Set ºBASSº and ºTREBº to the initial values and check if sounds is normal.
OK:
Malfunction disappears.
OK System is OK.
NG
2 Replace stereo component amplifier assy.
Replace the stereo component amplifier assy and check if it operates normally.
OK:
Malfunction disappears.
NG Replace radio receiver assy.
OK
End.
DIDA2±01

± DIAGNOSTICSAUDIO SYSTEM
DI±2027
2221 Author: Date:
2005 SEQUOIA (RM1146U)
Noise occurs
INSPECTION PROCEDURE
1 Check of speaker installation.
CHECK:
Check if each speaker is securely installed.
OK:
Each speaker is securely installed.
HINT:
The radio is equipped with a noise prevention system that blocks excessively loud noise. If such noise oc-
curs, check the all wiring is proper and that the antenna installation part ground and noise±prevention equip-
ment are installed.
Condition in which noise occursNoise type
Noise increases when the accelerator pedal is depressed, but stops when
the engine is stopped.Generator noise
Noise occurs during A/C or the heater operation.Blower motor noise
Noise occurs when the vehicle accelerates rapidly on an unpaved road or
after the ignition switch is turned on.Fuel pump noise
Noise occurs when the horn switch is pressed and released or when pressed
and held.Horn noise
Quiet noise occurs while the engine is running, but stops when the engine is
stopped.Ignition noise
Noise occurs synchronously with the blink of the turn signal.Flasher noise
Noise occurs during window washer operation.Washer noise
Noise occurs while the engine is running, and it continues even after the en-
gine is stopped.Water temperature sensor noise
Noise occurs during wiper operation.Wiper noise
Noise occurs when the brake pedal is depressed.Stop light switch noise
Others.Static electricity stored on the vehicle
HINT:

Identify the condition under which the noise occurs, and check the noise filter on the related part.

First ensure that the noise is not coming from the outside. Failure to do so makes noise source detec-
tion difficult and may lead to a misdiagnosis.

Noise should be removed in descending order of loudness.
NG Install it properly.
OK
Identification of noise source (See page DI±1964).
DIDA3±01

DI±2028
± DIAGNOSTICSAUDIO SYSTEM
2222 Author: Date:
2005 SEQUOIA (RM1146U)
Radio broadcast cannot be received (Bad reception)
INSPECTION PROCEDURE
1 Check if radio auto±search functions properly.
CHECK:
Check if the radio auto±search functions properly.
Perform the auto±search of the radio and check that it functions normally.
OK:
The radio auto±search functions properly.
OK Replace radio receiver assy.
NG
2 Check optional component.
CHECK:
Check for any optional component (sun shade film, telephone antenna etc.).
Check whether or not any optional component such as a sun shade film and telephone antenna is
installed.
OK:
Optional component is not installed.
NG Effect from optional component.
OK
DIDA4±01