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
Hint: components:
1. Drain manual transaxle oil (m/t transaxle)
torque: 39.2 Nvm (400 Kgf·cm, 29 ft·lbf)
2. Drain automatic transaxle fluid (a/t transaxle)
torque: 17.5 Nvm (178 Kgf·cm, 13 ft·lbf)
3. Remove front wheel
4. Remove engine under cover lh
5. Remove front axle hub lh nut
...
Inspection procedure
1 Inspect terminal voltage(od – body ground)
Disconnect the cruise control ecu connector.
turn the ignition switch to the on position.
measure the voltage between terminal od of cruise control
ecu and body ground.
Standard:
2 Inspect terminal voltage(od1 – bod ...
Inspection procedure
1 Inspect shift solenoid valve(s2)
Remove the shift solenoid valve s2.
measure the resistance according to the value(s) in the
table below.
Standard:
Connect the positive (+) battery lead to the solenoid connector
terminal, and the negative (–) battery lead to the
so ...


