Toyota Corolla Repair Manual: 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
No sound is heard from speaker in all modes
Wiring diagram
Inspection procedure
1 Check lcd (liquid crystal display) for lighting
Lcd illumination check
turn the ignition switch acc.
Turn the radio receiver assembl ...
Radio broadcast cannot be received (bad reception)
Inspection procedure
1 Check if radio auto–search functions properly
Check if the radio auto–search functions properly.
Perform the auto–search of the radio and check that it function ...
Other materials:
Registering a Bluetooth® phone for the first time
To use the hands-free system, it is necessary to register a Bluetooth® phone
with the system.
Once the phone has been registered, it is possible to use the hands-free system.
For details about registering a Bluetooth® device
1 Turn the Bluetooth® connection setting of your cellular phone on.
2 ...
Inspection procedure
Hint:
hand–held tester only:
narrowing down the trouble area is possible by performing ”a/f control” active
test (heated oxygen
sensor or other trouble areas can be distinguished).
perform active test using hand–held tester (a/f control).
Hint:
”a/f control” is the active test whi ...
Symptom simulation
Hint:
the most difficult case in troubleshooting is when no symptoms occurs. In such
cases, a thorough customer
problem analysis must be carried out. Then the same or similar conditions and
environment in which the
problem occurred in the customer’s vehicle should be simulated. No matter how ...