B1055:04 Code - Right Rear Door Audio Output 4 Circuit Open

Vehicles without Amplifier:
Each of the audio output channel circuits (+) and (-), at the radio have a DC bias voltage that is approximately one-half of battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5 V DC. The audio being played on the system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move and produce sound. The frequency (Hz) of the AC voltage signal is directly related to the frequency of the input (audio source playing) to the audio system. Both the DC bias voltage and the AC voltage signals are needed for the audio system to properly produce sound.

Vehicles with Amplifier:
The Media Oriented Systems Transport (MOST) is a high-speed multimedia network technology. The serial MOST bus uses a ring topology and synchronous data communication to transmit audio, video, data and control information between any devices attached.
The audio amplifier is a participant on the MOST network. The audio amplifier receives audio input and control information from the MOST bus.
Each of the audio output channel circuits (+) and (−), at the audio amplifier have a DC bias voltage that is approximately one-half of the battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5V DC. The audio being played on the system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move and produce sound.

The Diagnostic Trouble Code (DTC) will be set when an open is detected on the specified (+) (positive) or (−) (negative) signal circuit.

• Faulty Radio Unit
• Faulty Audio Amplifier (If equipped)
• Faulty Right Rear Door Speaker
• Right Rear Door Speaker harness is open or shorted
• Right Rear Door Speaker circuit poor electrical connection