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:

    Checking the engine coolant
    The coolant level is satisfactory if it is between the "MAX" and "MIN" lines on the reservoir when the engine is cold. Reservoir "MAX" line "MIN" line If the level is on or below the "MIN" line, add coolant up to the "MAX" line. ■Coolant selection Only use "Toyota Super Long Life Coolant" or ...

    Outside temperature display
    The temperature display shows temperatures within the range of -40°F (-40°C) to 122°F (50°C). ► Type A ► Type B ► Type C ► Type D ■The outside temperature is displayed when ►Vehicles without a smart key system The engine switch is in the “ON ...

    Inspection procedure
    1 Check side squib(lh) circuit(airbag sensor assy center – front seat airbag assy lh) Disconnect the negative (–) terminal cable from the battery, and wait at least for 90 seconds.  disconnect the connectors between the airbag sensor assy center and the front seat airbag assy ...