GM Service Manual Online
For 1990-2009 cars only

RADIO VOLUME GOES TO ZERO AFTER STARTING

SUBJECT: RADIO VOLUME GOES TO ZERO AFTER STARTING

VEHICLES AFFECTED: 1990-91 V MODELS

Some 1990-1991 Allantes may experience an intermittent condition where the radio volume setting will be reset to the minimum value when the vehicle is started. This may occur whether the last audio source selected was cassette tape, compact disc, or radio. The radio display will shown one character (-) as the volume setting during this condition, and no sound will be audible. The volume control buttons will operate normally to change the volume setting.

This condition may be caused by the radio control head software. During the first second of the power-up cycle, the radio control head directs the remote radio receiver chassis to momentarily mute the audio to prevent speaker pops and then sends another command to restore the volume level to the last stored setting. If the radio initialization routine is interrupted due to the key being moved from the "Run" to the "Crank" position while the volume is muted and before the message is sent to restore the volume, the muted level may be stored as the last setting and the radio will remain at zero volume.

Revised radio control head software is being developed, and information will be published at a later date concerning availability.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.