Toyota Sienna Service Manual: Speaker Circuit
DESCRIPTION
- When the vehicle has a built-in type amplifier, a sound signal is
sent from the radio receiver to the
speakers via the "6 Speaker System" circuit.
- When the vehicle has a separate type amplifier, a sound signal
from the radio receiver is amplified by
the stereo component amplifier and then transmitted to the speaker via the
"10 Speaker System"
circuit.
If there is a short in this circuit, the stereo component amplifier detects
it and stops output to the speakers.
Thus sound cannot be heard from the speakers even if there is no malfunction in
the stereo component
amplifier or speakers
WIRING DIAGRAM



1 CHECK HARNESS AND CONNECTOR

- Disconnect the connectors shown in the illustration from
the stereo component amplifier or radio receiver and
speakers.
- 10 Speaker System:
Measure the resistance between each of the front No. 2
speakers and the stereo component amplifier to check
for an open circuit in the wire harness.
Standard resistance:
Below 1 Ω
- 6 speaker System:
Measure the resistance between each of the front No. 2
speakers and the radio receiver to check for an open
circuit in the wire harness.
Standard resistance:
Below 1 Ω
- Measure the resistance between each of the front No. 2
speakers and each of the front No. 1 speakers to check
for an open circuit in the wire harness.
Standard resistance:
Below 1 Ω
- 10 Speaker System:
Measure the resistance between each of the rear
speakers and the stereo component amplifier to check
for an open circuit in the wire harness.
Standard resistance:
Below 1 Ω
- 6 Speaker System:
Measure the resistance between each of the rear
speakers and the radio receiver to check for an open
circuit in the wire harness.
Standard resistance:
Below 1 Ω
- 10 Speaker System:
Measure the resistance between each of the rear stereo
component speakers and the stereo component
amplifier to check for an open circuit in the wire harness.
Standard resistance:
Below 1 Ω
- 10 Speaker System:
Measure the resistance between the front stereo
component speaker and the stereo component amplifier
to check for an open circuit in the wire harness.
Standard resistance:
Below 1 Ω

- 10 Speaker System:
Measure the resistance between the woofer box speaker
and the stereo component amplifier to check for an open
circuit in the wire harness.
Standard resistance:
Below 1 Ω
- Measure the resistance between the each speaker and
body ground to check for a short circuit in the wire
harness.
Standard resistance:
10 kΩ or higher
2 INSPECT FRONT NO. 1 SPEAKER
- Resistance check.
- Measure the resistance between the terminals of
the speaker.
Standard resistance:
10 Speaker System:
4 to 6 Ω
6 Speaker System:
Approximately 4 Ω
3 INSPECT REAR SPEAKER
- Resistance check.
- Measure the resistance between the terminals of
the speaker.
10 Speaker System:
Approximately 2.4 Ω
6 Speaker System:
Approximately 4 Ω
4 INSPECT FRONT NO. 2 SPEAKER
- Check that the malfunction disappears when another
speaker in good condition is installed.
Standard:
Malfunction disappears.
HINT:
- Connect all the connectors to the front No. 2 speaker.
- When there is a possibility that either the right or left
front speaker is detective, inspect by interchanging
the right one with the left one.
- Perform the above inspection on both LH and RH
sides.
5 CONFIRM MODEL
Result

6 INSPECT WOOFER BOX SPEAKER

- Resistance check.
- Measure the resistance according to the value(s) in
the table below.
NOTICE:
The speaker should not be removed for
checking.
Standard resistance

7 INSPECT REAR STEREO COMPONENT SPEAKER
- Check that the malfunction disappears when another
speaker in good condition is installed.
OK:
Malfunction disappears.
HINT:
- Connect all the connectors to the rear stereo component
speaker.
- When there is a possibility that either the right or left rear
speaker is detective, inspect by interchanging the right one
with the left one
8 INSPECT FRONT STEREO COMPONENT SPEAKER
- Resistance check.
- Measure the resistance between the terminals of
the speaker.
Standard resistance:
1.2 to 2.2 Ω
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
DESCRIPTION
Power is supplied to the radio receiver and steering pad switch illumination
when the light control switch is
in the TAIL or HEAD position.
WIRING DIAGRAM
INSPECTION PROCEDURE
N ...
DESCRIPTION
The radio receiver sends a sound signal to the stereo component amplifier
through this circuit.
The sound signal that has been sent is amplified by the stereo component
amplifier, ...
Other materials:
Fuel Pump Control Circuit
DESCRIPTION
The FUEL PUMP relay switches the fuel pump speed according to the engine
conditions. The fuel pump
operates when the ECM receives the starter-operating signal (STA) and
crankshaft-rotating signal (NE).
The FUEL PUMP relay is turned ON while the engine is idling or operating at l ...
Inspection
1. INSPECT LOWER BALL JOINT ASSEMBLY FRONT LH
(a) As shown in the illustration, flip the ball joint stud
back and forth 5 times, before installing the nut.
(b) Using a torque wrench, turn the nut continuously at
a rate of 3 - 5 seconds per 1 turn and take the
torque reading on the 5th tur ...
Radio and Navigation Assembly Communication Error
INSPECTION PROCEDURE
1 IDENTIFY THE COMPONENT SHOWN BY THE SUB-CODE
Enter the diagnostic mode.
Press the "LAN Mon" switch to change to "LAN Monitor"
mode.
Identify the component shown by the sub-code.
HINT:
"110 (multi-display)" i ...