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:
Navigation Voice Circuit
DESCRIPTION
This circuit is used when the voice guidance in the navigation system is on.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK HARNESS AND CONNECTOR (RADIO AND NAVIGATION ASSEMBLY - STEREO
COMPONENT AMPLIFIER)
Disconnect the radio and navigation assembly connector
R13 and s ...
ECU Power Source Circuit
DESCRIPTION
This is the power source for the tire pressure warning ECU.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
When replacing the tire pressure warning ECU, read the transmitter IDs
stored in the old ECU
using the intelligent tester and write them down before removal.
It is neces ...
Lumbar support adjuster assembly
INSPECTION
1. INSPECT LUMBAR SUPPORT ADJUSTER ASSEMBLY
Check operation of the lumbar support adjuster
motor.
Check if the lumbar support adjuster moves
smoothly when the battery is connected to the
lumbar support adjuster motor connector
terminal.
OK
If the r ...
