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:
Shift Solenoid "E" Control Circuit
DESCRIPTION
Shifting from 1st to 5th is performed in combination with "ON" and "OFF"
operation of the shift solenoid
valves SL1, SL2, SL3, S4 and SR which are controlled by the ECM. If an open or
short circuit occurs in
either of the shift solenoid valves, the ECM cont ...
Symptom confirmation and diagnostic trouble code
HINT:
The diagnostic system in the SIENNA has various
functions.
The first function is the Diagnostic Trouble Code
(DTC) check. A DTC is a code stored in the ECU
memory whenever a malfunction in the signal circuits
to the ECU occurs. In a DTC check, a previous
malfunction's DTC can be ...
Problem symptoms table
HINT:
Use the table below to help determine the cause of the
problem symptom. The likely causes of the problem are
indicated in descending order. Check each suspected area
in order. Repair or replace faulty parts or perform
adjustments as necessary.
Inspect the fuse and rel ...
