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:
Terminals of ecu
1. A/C AMPLIFIER
HINT:
Check from the rear of the connector while it is
connected to the A/C amplifier.
(a) Waveform 1:
(b) Waveform 2: ...
Inspection
1. INSPECT BRAKE DRUM INSIDE DIAMETER
(a) Using a brake drum gauge or equivalent, measure
the inside diameter of the drum.
Standard inside diameter:
254.0 mm (10.00 in.)
Maximum inside diameter:
256.0 mm (10.08 in.)
2. INSPECT REAR DRUM BRAKE SHOE LINING THICKNESS
(a) Using a ruler, ...
Reassembly
1. INSTALL REAR DIFFERENTIAL PINION SHAFT
(a) Install the 2 thrust washers to the 2 side gears.
(b) Install the 2 side gears, 2 differential pinion gears, 2
differential pinion thrust washers and differential
pinion shaft to the differential case.
HINT:
Align the holes of the differentia ...
