GM Service Manual Online
For 1990-2009 cars only

Diagnostic Fault Information

Important: Always perform the Diagnostic Starting Point - Entertainment prior to using this diagnostic procedure.

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Battery Power

1

1

1

--

Entertainment and Comfort Serial Data

1

1

1

--

Ground

--

2

2

--

1. Loss of audio output on the channel during Remote Playback Device play.

2. Audio noise during Remote Playback Device play.

Circuit/System Description

The remote playback device sends its audio signals through the radio to be heard through the vehicle speakers.

Diagnostic Aids

This diagnostic assumes that the radio is functional and that the remote playback device has some audio output. The remote playback device audio signal outputs, and the radio audio signal inputs are also a possible cause of this symptom if the physical operation of the system appears to be working.

Reference Information

Schematic Reference

Radio/Audio System Schematics

Connector End View Reference

Entertainment Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Special Tools Required

J 39916-A

Circuit/System Verification

  1. Ignition ON.
  2. Turn the radio on. Insert a CD into the CD player.
  3. Play the CD.
  4. Adjust the balance control to determine which channel is inoperative.

Circuit/System Testing

  1. Ignition ON, radio and remote playback device - CD player on with CD playing. Test for 0-3 vac audio signal on the appropriate left or right audio signal.
  2. If the AC audio signal voltage is not seen, test the appropriate left or right audio signal for a short to voltage, short to ground or an open/high resistance. If circuit tests normal, continue the following tests before replacing the remote playback device.
  3. Test the audio common circuit to ground for less than 1 volt dc.
  4. If the voltage is greater than 1 volt dc. Test the audio common circuit for a short to voltage or an open/high resistance.
  5. If the circuits test normal, bench test the remote playback device by connecting battery voltage, ground and entertainment and comfort serial data circuits. Play a CD and test for the 0-3 vac signal voltage on the left and right audio outputs to audio common.
  6. If the 0-3 vac signal voltage is not present on the outputs, replace the remote playback device.
  7. If all circuits test normal, test or replace the radio.

Repair Instructions

    •  Remote CD Changer Replacement
    •  Radio Replacement