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:

    Starting the engine
    1 Continuously variable transmission: Ensure that the shift lever is in P and depress the brake pedal. Manual transmission: Shift the shift lever to N and depress the clutch pedal. 2 Touch the Toyota emblem side of the electronic key to the engine switch. When the electronic key is detected, a ...

    Towing with a wheel-lift type truck
    ► From the front Release the parking brake. ► From the rear Use a towing dolly under the front wheels. Vehicles without a smart key system: When not using a towing dolly, turn the engine switch to the “ACC” position and shift the shift lever to N. Vehicles with a smart key ...

    Cleaning and protecting the vehicle interior
    Perform cleaning in a manner appropriate to each component and its material. Protecting the vehicle interior Remove dirt and dust using a vacuum cleaner. Wipe dirty surfaces with a cloth dampened with lukewarm water. If dirt cannot be removed, wipe it off with a soft cloth dampened with neut ...