Each of the audio output channel circuits (+) and (-), at the radio and audio amplifier have a DC bias voltage that is 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. This voltage will vary depending on what type of audio is being listened to, talk or music, and type of music, as well as the volume setting of the system. Low volume and talk settings will measure around 1V AC and less, where constant music may measure 3V AC and slightly higher.

The DTC will set when the radio detects a short to voltage or short to ground in any of the low level audio signal circuits (+) and (-).

No sound is present from one or more of the speakers.

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Entertainment/Communication Connector End Views

Description and Operation

Radio/Audio System Description and Operation

Electrical Information Reference

1. Ignition OFF, disconnect the C2 harness connector at the audio amplifier.
2. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.

•	Left front low level audio signal (+) terminal A7

•	Left front low level audio signal (-) terminal A6

•	Right front low level audio signal (+) terminal B6

•	Right front low level audio signal (-) terminal B7

•	Left rear low level audio signal (+) terminal A4

•	Left rear low level audio signal (-) terminal A5

•	Right rear low level audio signal (+) terminal B5

•	Right rear low level audio signal (-) terminal B4

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

3. If all circuits test normal, replace the audio amplifier.

1. Ignition OFF, disconnect the C2 harness connector at the audio amplifier.
2. Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.

•	Left front low level audio signal (+) terminal B10

•	Left front low level audio signal (-) terminal B9

•	Right front low level audio signal (+) terminal B8

•	Right front low level audio signal (-) terminal B7

•	Left rear low level audio signal (+) terminal B6

•	Left rear low level audio signal (-) terminal B5

•	Right rear low level audio signal (+) terminal B4

•	Right rear low level audio signal (-) terminal B3

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

3. If all circuits test normal, replace the audio amplifier.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.