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

  1. Adjust the sound quality.
  1.  Operate the radio receiver assy to adjust the sound quality.

    Standard: malfunction disappear.

2 Compare it with another car of same model

2 Compare it with another car of same model

  1. Compare it with another vehicle of the same model.
  1.  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

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

4 Inspect front no.1 Speaker assy

4 Inspect front no.1 Speaker assy

  1. Preparation for check
  1.  disconnect the connector of the speaker.
  1.  resistance check
  1.  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

5 Inspect front no.2 Speaker assy

  1. 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

6 Inspect rear speaker assy

  1. Preparation for check
  1.  disconnect the connector of the speaker.
  1.  resistance check
  1.  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)

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

  1. Check that the continuity between terminals at each condition, as shown in the chart.

Standard:

  1. Check that the voltage between terminals at each condition, as shown in the chart.

Standard:

Repair or replace harness or connector

Repair or replace harness or connector

    Share this page:

    Other materials:

    Inspection procedure
    1 Check door lock When the door does not operate manually, proceed to ”a”.  when the door does not operate via the key, proceed to ”b”. 2 Inspect door lock control switch W/ power window: remove the power window regulator master switch assy.  Inspect th ...

    Emission inspection and maintenance (I/M) programs
    Some states have vehicle emission inspection programs which include OBD (On Board Diagnostics) checks. The OBD system monitors the operation of the emission control system. If the malfunction indicator lamp comes on The OBD system determines that a problem exists somewhere in the emission control sy ...

    Maintenance requirements
    To ensure safe and economical driving, day-to-day care and regular maintenance are essential. It is the owner’s responsibility to perform regular checks. Toyota recommends the following maintenance: General maintenance General maintenance should be performed on a daily basis. This can be don ...