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
Screen Flicker or Color Distortion
INSPECTION PROCEDURE
1 CHECK DISPLAY SETTING
Enter the display adjustment screen by pressing the
"DISPLAY" switch.
Reset display settings (contrast, brightness) and check
...
Map Disc cannot be Inserted
INSPECTION PROCEDURE
1 CHECK RADIO AND NAVIGATION ASSEMBLY
Check if a disc is inserted into the MAP disc slot.
Check if "DISC IN" is displayed.
OK:
"DISC IN&quo ...
Other materials:
Steering wheel audio
switches
Some audio features can be controlled using the switches on
the steering wheel.
Operation may differ depending on the type of audio system or
navigation system. For details, refer to the manual provided with
the audio system or navigation system.
Operating the audio system using the steering ...
Adjustment
HINT:
On the RH side, use the same procedures as on the LH
side.
Since a centering bolt is used as door hinge mounting
bolts on the body side and the door side, the door cannot
be adjusted with them on. Substitute a bolt with a washer
for the centering bolt.
1. INSPECT BACK DOOR PAN ...
Inspection
1. INSPECT MASS AIR FLOW METER
Visually check for any foreign matter on the
platinum hot wire (heater) of the mass air flow
meter.
OK:
There is no foreign matter.
If the result is not as specified, replace the mass air
flow meter.
Measure the resistance according to the ...
