For 1990-2009 cars

# RADIO CONTROLS INOPERATIVE/ DISPLAY BLANK (EXCHANGE HEAD)

#### SUBJECT: RADIO CONTROLS INOPERATIVE OR DISPLAY BLANK WHEN COLD (EXCHANGE RADIO CONTROL HEAD)

#### VEHICLES AFFECTED: 1990-91 'D'

Some 1990-1991 Broughams equipped with the base or uplevel radio system (RPO's UX1 or U1H) may experience a condition where the radio display will be blank or controls inoperative when ambient temperatures are below 40 degrees F (5 degrees C). If the TECH1 is used for diagnosis when the condition is present, the remote radio receiver chassis will play and respond normally to TECH1 commands. Depressing the volume control knob to display the time will normally return the system to proper operation.

This condition may be caused by software contained in the radio control head. Revised radio control head software has been developed, and the control head should be exchanged.

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.