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:
Problem symptoms table
HINT:
Before performing verification listed in the table below,
check the fuse and relay.
Check the circuits for each problem symptom in the order
given in the table below, and proceed to the relevant page.
CLEARANCE SONAR SYSTEM:
*1: with Front Clearance Sonar
*2: wit ...
Diagnostic trouble code chart
HINT:
If a malfunction code is displayed during the DTC check,
check the circuit indicated by the DTC. For details of each
code, turn to the page for the respective "DTC Code" in the
DTC chart.
DTC chart of ABS:
DTC chart of VSC:
...
On-vehicle inspection
1. CHECK RADIATOR RESERVOIR CAP SUBASSEMBLY
a) Measure the valve opening pressure.
(1) If there are water stains or foreign matter on
rubber packings 1, 2 or 3, clean the part(s) with
water and finger scouring.
(2) Check that rubber packings 1, 2 and 3 are not
deformed, cracked or swol ...
