Sound Quality Diagnosis - Electrical Noise Test

Sound Quality Diagnosis - Electrical Noise Test

Special Tools Required

- Diagnostics CD 07AAZ-SDBA100

Electrical Noise Test

Do this test to check for electrical noise being induced into the audio system.

NOTE: Electrical noise may be caused by outside sources that cannot be handled by the audio system. Make sure you remove any cell phones and/or turn off any aftermarket devices before beginning this test.

1. Insert the audio diagnostic CD (T/N 07AAZ-SDBA100) into the audio unit.

2. Play track No. 4 (digital zero) at a normal, or slightly higher than normal, volume level.

3. Operate any electrical device that may create electrical noise in the audio system, including starting the engine.

4. Play track No. 5 (near digital zero) at a normal, or slightly higher than normal, volume level.

5. Operate any electrical device that may create electrical noise in the audio system, including starting the engine.

6. Play track No. 6 (SNR) at a normal, or slightly higher than normal, volume level.

7. Operate any electrical device that may create electrical noise in the audio system, including starting the engine.
- If no abnormal noise is heard, go to the individual speaker test. Sound Quality Diagnosis - Individual Speaker Test

- If the noise is present only during the SNR track, replace the audio unit.

- If the noise is heard during the digital zero or near digital zero track, check for:
- Poor ground at the audio unit, amplifier, engine, or battery cable

- Pinched or shorted speaker or amplifier wire

- Faulty amplifier

- Faulty audio unit

- Other faulty components causing excessive electrical noise (ignition coils, alternator, door lock actuators, etc.). Disconnect any suspect components, and then replay the tracks that were originally noisy. If the noise is gone, check the component's circuit and the component.