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:
Coolant
Replacement
1. Drain coolant
Caution:
to avoid the danger of being burned, do not remove the radiator
cap while the engine and radiator are still hot, as fluid
and steam can be blown out under pressure.
remove the radiator cap.
loosen the radiator and engine drain plugs, a ...
Circuit description
The fuel trim is related to the feedback compensation value, not to the basic
injection time. The fuel trim includes
the short–term fuel trim and the long–term fuel trim.
The short–term fuel trim is the short–term fuel compensation used to maintain
the air–fuel ratio at stoichiometric
air–f ...
Automatic door locking and unlocking systems
The following functions can be set or cancelled:
*1: Vehicles with an automatic transmission or continuously variable transmission
*2: Vehicles with a smart key system
■ Setting and canceling the functions
To switch between set and canceled, follow the procedure below:
1 Vehicles withou ...