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:
ECU Power Source Circuit
DESCRIPTION
This circuit provides power to operate the theft deterrent (warning) ECU.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FUSE (ECU-B)
Remove the ECU-B fuse from the engine room J/B.
Measure the resistance.
Standard resistance:
Below 1 Ω
2 CHECK INSTRUMENT PANEL ...
Light Sensor Circuit Malfunction
DTC B1244 Light Sensor Circuit Malfunction
DESCRIPTION
This DTC is output when failure in the light sensor circuit is detected.
DTC No.
DTC Detection Condition
Trouble Area
B1244
Malfunction of automatic light control sensor
Open or short of a ...
Rear Air Conditioning Relay Circuit
DESCRIPTION
The RR A/C relay is switched on by signals from the A/C amplifier. It
supplies power to the rear blower
motor.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT RELAY (RR A/C)
(a) Remove the RR A/C relay from the No. 3 relay block.
(b) Measure the resistance according to t ...
