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:
Diagnosis system
1. DESCRIPTION
Front power seat control system data can be read
through the Data Link Connector 3 (DLC3) of the
vehicle. When the system seems to be
malfunctioning, use the intelligent tester to check for
malfunctions and perform repairs.
2. CHECK DLC3
The vehicle us ...
Mute Signal Circuit between Radio Receiver and Television Display
Assembly
DESCRIPTION
The radio receiver controls the volume according to the MUTE signal from the
television display
assembly.
The MUTE signal is sent to reduce noise and a popping sound generated when
switching the mode, etc.
If there is an open in the circuit, noise can be heard from the speake ...
Distance Control Switch Circuit
DESCRIPTION
The distance control switch sets the vehicle-to-vehicle distance mode. The
distance control switch is
installed in the steering pad switch. The vehicle-to-vehicle distance set value
can be changed by
operating the steering pad switch (distance control switch) while the dynamic
l ...
