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:
Driving support system
information display
■ Driving support system
information
Select to display the operational
status of the following systems:
Dynamic radar cruise control
LTA (Lane Tracing Assist)
LDA (Lane Departure Alert)
■ Navigation system-linked
display (if equipped)
Select to display the following
navigation system-linked ...
If a warning message or indicator is displayed (vehicles with a multi-information
display)
If a warning is shown on the multi-information display, stay calm and perform
the following actions:
1 Master warning light
The master warning light also comes on or flashes in order to indicate that a message
is currently being displayed on the multiinformation display.
2 Multi-information d ...
Inspection procedure
1 Inspect dlc3 terminal voltage(ts terminal)
Turn the ignition switch to on.
measure voltage between terminals ts and cg of dlc3.
Ok:
voltage: 10 – 14 v
2 Check harness and connector(dlc3 – body ground)
Check for open and short circuit in harness and connector between
...


