This bulletin supersedes bulletin T-91-14 which should be discarded. This bulletin is being revised to update part availability.
Some 1990-1991 Allantes may experience an intermittent condition where the audio system 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 display will show one caret 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. The condition occurs when the radio initialization routine is interrupted during the first second of the power-up cycle due to the key being moved from the "Run" to the "Crank" position.
Revised control head software has been developed and is incorporated in exchange combo panels available through Dayton Speedometer using the procedure described on page 15 of DSIB 91-1-1. Their telephone number to request a pre-exchange combo panel is (800) 543-9687 or (800) 543-0179 (within the state of Ohio). The combo panels will be shipped minus the CD mechanism. It will, therefore, be necessary to swap the CD mechanism from the exchange unit as described on page 9A-50 of the 1990 Allante Service Information Manual.
For warranty purposes use Labor Operation N4150 at 1.0 hour. This includes transferring the CD mechanism into the pre-exchange Combo panel.
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.