LAMP MONITOR MALFUNCTION DIAGNOSIS REPLACE LAMP MODULE

SUBJECT: LAMP MONITOR MALFUNCTION

MODELS AFFECTED: 1991 PARK AVENUE AND ULTRA

Some 1991 Park Avenue and Ultra models with Option U46 Exterior Lamp Monitor may exhibit one of the following conditions due to a transient voltage spike interfering with the logic of the module.

1. LED's remain lit all the time. Cycling the ignition may temporarily correct the problem.

2. LED's remain in the diagnostic mode where they flicker continuously at half intensity. Cycling the ignition may temporarily correct the problem.

3. Module has lost memory and must be reinitialized. To initialize a module, the park lights must be turned on to provide a basis of operation.

Vehicle Breakpoint

Start of Production - M1612000

Follow the service manual using normal diagnostic procedures. If no problem is found and one of the above conditions exist, replace the lamp monitor with Part No. 12088548.

Parts are currently available from GMSPO.

WARRANTY INFORMATION:

Use currently available Labor Operation and Time.

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.