Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Audio system / Sound quality is bad in all modes (volume is too low)
Toyota Corolla (E120): Sound quality is bad in all modes (volume is too low)
Wiring diagram
Inspection procedure
1 Adjust sound quality
- Adjust the sound quality.
- Operate the radio receiver assy to adjust the sound quality.
Standard: malfunction disappear.


2 Compare it with another car of same model
- Compare it with another vehicle of the same model.
- Compare with the vehicle of the same type which does not have a
trouble to see if there is any
difference in the condition of trouble occurrence.
Standard: no difference found.


3 Check harness and connector(between radio receiver assy and speaker)


4 Inspect front no.1 Speaker assy
- Preparation for check
- disconnect the connector of the speaker.
- resistance check
- check the resistance between the terminals of the speaker.
Notice
: the speaker should not be removed for checking.
Standard value: 4 Ω


5 Inspect front no.2 Speaker assy
- Check that malfunction disappear when a known good speaker is installed.
Standard: malfunction disappear.
Hint
: connect the all connectors of speakers.


6 Inspect rear speaker assy
- Preparation for check
- disconnect the connector of the speaker.
- resistance check
- check the resistance between the terminals of the speaker.
Notice
: the speaker should not be removed for checking.
Standard value: 6 Ω


7 Inspect radio receiver assy(+b, acc, gnd)

- Check that the continuity between terminals at each condition, as shown in the chart.
Standard:

- Check that the voltage between terminals at each condition, as shown in the chart.
Standard:



Repair or replace harness or connector
Other materials:
Overhaul
1. Precaution
2. Disconnect battery negative terminal
3. Inspect place front wheels facing straight ahead
4. Remove horn button assy
Notice:
if the airbag connector is disconnected with the ignition
switch being at on, dtcs will be recorded.
using a torx socket wrench, loosen the ...
General maintenance
Listed below are the general
maintenance items that
should be performed at the
intervals specified in the
"Owner's Warranty Information
Booklet" or "Owner's
Manual Supplement/Scheduled
Maintenance Guide". It
is recommended that any
problem you notice should
be brought to the attention
of your Toyota ...
Inspection procedure
1 Input signal check
See the input signal check on page 05–745.
check the indicator light when the clutch pedal is depressed.
Ok:
the indicator light goes off when the clutch pedal is
depressed.
2 Inspect terminal voltage(d)
Turn the ignition switch to on.
&n ...


