Toyota Sienna Service Manual: Poor Sound Quality in All Modes (Low Volume)
INSPECTION PROCEDURE
1 CHECK AUDIO SETTINGS
- Set "BASS", "MID", and "TREB" to the initial values and check that sound is normal.
OK: Malfunction disappears.
2 COMPARE WITH ANOTHER VEHICLE OF SAME MODEL
- Compare with another vehicle of the same model.
- Compare with another vehicle of the same model which does not have trouble to see if there is any difference in the sound quality.
OK: No difference is found.
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
Radio Broadcast cannot be Received or Poor Reception
INSPECTION PROCEDURE
1 CHECK RADIO RECEIVER
Check the radio's automatic station search function.
Check the radio's automatic station search function
by activating it.
OK:
The ra ...
Vehicle Speed Signal Circuit between Radio Receiver and Combination
Meter
DESCRIPTION
This circuit is necessary for the ASL (Auto Sound Leveliser) built into the
radio receiver.
Speed signals are received from the combination meter and used for the ASL.
The ASL fun ...
Other materials:
Back Sonar Sensor LH Circuit
DESCRIPTION
An ultrasonic sensor consists of a sensor portion that transmits and receives
ultrasonic waves and a preamplifier
that amplifies them. The ultrasonic sensor outputs the ultrasonic waves and
sends the received
signals to the clearance warning ECU.
WIRING DIAGRAM
INSPECTION PR ...
Input instructions
(a) The general VIN input instructions using the
intelligent tester are shown below:
(b) The arrow buttons (UP, DOWN, RIGHT and LEFT)
and numerical buttons (0 to 9) are used to input the
VIN.
(c) Cursor Operation
To move the cursor around the tester screen, press
the RIGHT and LEFT buttons. ...
Inspection
1. INSPECT POWER STEERING RACK
(a) Using a dial indicator, check the power steering rack
for runout and for teeth wear and damage.
Maximum runout:
0.3 mm (0.012 in.)
If necessary, replace the rack & pinion power
steering gear assembly.
(b) Check the back surface for wear and damag ...