Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers) - Except THX(R) Audio System

PINPOINT TEST B: POOR QUALITY/DISTORTED/NO SOUND FROM ONE OR MORE SPEAKERS (NOT ALL SPEAKERS) - EXCEPT THX(R) AUDIO SYSTEM

Normal Operation
The audio control module (ACM) directs audio signals to the front door speakers and to the rear entertainment module (RETM) (if equipped) in the form of a fluctuating AC voltage. The tweeter speakers (if equipped) are wired in series with the front door speakers. The rear door speakers receive audio signals through the RETM (if equipped) or directly from the ACM.

If the vehicle is equipped with the DVD entertainment system, the RETM mutes the speaker output to the rear speakers when the audio system is in dual-play mode. Make sure the audio system is in single-play mode before diagnosing a symptom of no sound to the rear speakers.

For the navigation system, if the voice guidance setting is set to zero rather than to off, it may appear that the front speakers intermittently produce no sound. Make sure the voice guidance setting is not set to zero before addressing a concern with the front speakers.

- DTC B2965 (Audio System Speaker Circuit Fault) - sets when an open, a short to ground, or a short to voltage is detected on the front or rear door speaker circuits. The ACM checks for faults once every 500ms during normal operation, or for any duration during the ACM self-test. The following should also be noted:
- The Audiophile ACM does not check for opens in the front door speakers.
- The navigation ACM does not check for opens.

For some ACMs, a short to ground or short to voltage in the circuitry to one of the speakers will cause all speakers to lose sound due to the built-in overload protection feature of the ACM. In this case, DTC B2965 will set in the ACM, and this pinpoint test should be followed to isolate the damaged circuit.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Speaker
- RETM (if equipped)
- ACM

B1-B5:

B5-B8:

B8-B10:

B10-B12:

B12-B15:

B15-B18: