Audio System - Humming/Booming Noise From Speakers

06-092

December 12, 2008

*Applies To:
See VEHICLES AFFECTED*

Booming or Humming Noise From Speakers While Driving

(Supersedes 06-092, dated December 22, 2006, to update the information marked by black bars and asterisks)

SYMPTOM
A booming or humming noise is heard from the speakers while driving with the radio on or off.

PROBABLE CAUSE
A faulty ANC (active noise control) unit.

CORRECTIVE ACTION
Replace the ANC control unit.





*VEHICLES AFFECTED*





*PARTS INFORMATION*

WARRANTY CLAIM INFORMATION

In warranty:
The normal warranty applies.

Flat Rate Time: 0.6 hour

Failed Part: P/N 39200-STW-A01
H/C 8159055

Defect Code: 03217

Symptom Code: 04201

Template ID: 06-092A

Skill Level: Repair Technician

Out of warranty:
Any repair performed after warranty expiration may be eligible for goodwill consideration by the District Parts and Service Manager or your Zone Office. You must request consideration, and get a decision, before starting work.

DIAGNOSIS

1. Start the vehicle.

2. Turn the radio on, and make sure it operates normally.

3. Turn the radio off.

4. Press and hold the preset buttons number 1 and number 6, then press the VOL push PWR button. The audio system enters its diagnostic mode and Diagnosis (or Diag) appears on the display. Release the preset buttons.

5. Press the number 1 preset button. ANC ON appears on the display.

6. Press the number 1 preset button again to turn the ANC OFF. You should hear a humming noise coming from the speakers for about 60 seconds.

NOTE:
^ To turn the humming off, press the number 1 preset button to turn the ANC ON, and wait for the hum to stop. Press the number 1 preset button again to turn the ANC OFF.

^ Repeatedly pressing the number 1 preset button cycles the audio unit ANC ON and ANC OFF, but the ANC control unit won't hum until the ignition switch is turned to LOCK (0) and ON (II), and you put the audio system back into Diagnosis mode.

^ When the ignition switch is turned to LOCK (0) and ON (II) again, the audio system defaults to its ANC ON mode.

7. With the ANC OFF (audio unit on), test-drive the vehicle as described by the customer. If you can't reproduce the booming or humming noise, go to REPAIR PROCEDURE.

8. If you can still hear the booming or humming noise, disregard this bulletin and do the ANC troubleshooting in the service manual.

REPAIR PROCEDURE

1. Replace the ANC control unit.

^ Refer to page 22-375 of the 200608 Pilot Service Manual, or

^ Online, enter keyword ACTIVE and select Active Noise Control Unit Removal/Installation (2WD) from the list.

2. Test-drive the vehicle to confirm the repair.