Frequency Sweep

NOTE:  If possible, have the client demonstrate their complaint, and record the conditions under which the complaint occurred. Try to reproduce the complaint in a known-good vehicle.

Do this test to find rattles or reverberations that may cause a perception of poor sound quality.

1. Insert the audio Diagnostic CD (07AAZ-SDBA100) into the audio-navigation unit or the audio unit.

2. Play track No. 13 (sweep from 500 Hz to 35 Hz) at a normal, or slightly higher than normal, volume level.Listen to each speaker for poor sound quality or reverberations caused by specific frequencies. Use the voice-over to estimate the frequency that causes the vibration. Use the audio-navigation unit's or the audio unit's fader and balance settings to help isolate the channel with the problem.

• If vibrations or poor sound quality are heard, go to step 4.
• If no vibrations or poor sound quality are heard, go to Sound Judging.

4. Choose the appropriate track from No. 14 to 25 (small range frequency sweep) or 26 to 53 (single frequencies) to recreate the frequency that caused the poor sound quality or vibration located in step 3; this aids in diagnosis of the cause.

NOTE: 

When you get to the track that recreates the problem, select the repeat function on the audio-navigation unit or the audio unit, this will help you isolate the cause.

5. Replace or insulate the source of the vibrations or, if the speaker is the source of the poor sound quality, replace it.