DESCRIPTION
The Automatic Sound Levelizer (ASL) function automatically adjusts the audio system volume level in order to compensate for increased vehicle noise (vehicle noise tends to increase as vehicle speed increases). The ASL adjusts the volume level based upon vehicle speed signals that it receives from the combination meter assembly.
The radio and display receiver assembly recognizes that the vehicle is being driven and makes it impossible to connect or register a "Bluetooth" device while driving.
HINT:
WIRING DIAGRAM
PROCEDURE
1. |
INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM) |
(a) Check the output waveform.
(1) Remove the combination meter assembly with the connector still connected.
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(2) Connect an oscilloscope to terminal F4-6 (+S) and body ground.
*a |
Component with harness connected (Combination Meter Assembly) |
- |
- |
(3) Turn the ignition switch to ON.
(4) Turn a wheel slowly.
(5) Check the signal waveform according to the condition(s) in the table below.
Item |
Condition |
---|---|
Measurement terminal |
F4-6 (+S) - Body ground |
Tool setting |
5 V/DIV., 20 ms./DIV. |
Vehicle condition |
Wheel being rotated |
OK:
The waveform is similar to that shown in the illustration.
HINT:
When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.
NG | ![]() |
GO TO METER / GAUGE SYSTEM |
|
2. |
CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - COMBINATION METER ASSEMBLY) |
(a) Disconnect the F129 radio and display receiver assembly connector.
(b) Disconnect the F4 combination meter assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
F129-27 (SPD) - F4-6 (+S) |
Always |
Below 1 Ω |
OK | ![]() |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
Toyota CH-R Service Manual > Vacuum Warning Switch: On-vehicle Inspection
ON-VEHICLE INSPECTION
PROCEDURE
1. INSPECT BRAKE FLUID LEVEL IN RESERVOIR
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2. INSPECT BRAKE BOOSTER ASSEMBLY
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3. REMOVE OUTER COWL TOP PANEL SUB-ASSEMBLY
Click here
4. INSPECT VACUUM WARNING SWITCH ASSEMBLY
(a) Start the engine and stop it after 1 or 2 minute ...
Toyota CH-R Service Manual > Rear Suspension System: Problem Symptoms Table
PROBLEM SYMPTOMS TABLE
HINT:
Use the table below to help determine the cause of problem symptoms. If multiple
suspected areas are listed, the potential causes of the symptoms are listed in order
of probability in the "Suspected Area" column of the table. Check each symptom by
check ...