For 1990-2009 cars

# NEW TWILIGHT SENTINEL AND DAYTIME RUNNING LAMP MODULES

#### VEHICLES AFFECTED: 1990 C/H MODELS

The 1990 C/H Model breakpoint numbers are as follows:

Plant Division VIN

Buick City Buick LH510815 (DRL module Canada only) Buick City Oldsmobile LH346425 (DRL module Canada only) Lake Orion Cadillac L4323744 Lake Orion Oldsmobile L4345160 Wentzville Buick All 1990 Models Wentzville Oldsmobile L1831878 (DRL module Canada only) Wentzville Pontiac L1257540

#### CONDITION:

A new Twilight Sentinel/Daytime Running Lamp module has been developed to correct the following conditions on the subject vehicles:

1. Headlamps coming on and timing out when turning on the park lamp switch with the key in the 'Off' position. This may occur with the Twilight Sentinel system on or off.

2. Headlamps will not flash at night when the Theft Deterrent system is activated.

3. Headlamps turn on and off (repeated cycles) at dawn or dusk. (U.S. vehicles only)

Headlamps cycle from daytime intensity to night intensity (repeated cycles) at dusk or dawn. (Canadian vehicles only)

U.S. ONLY - To correct these conditions, replace the Twilight Sentinel module using part number 16515789.

CANADA ONLY - To correct this condition, replace the Daytime Running Lamp module part number 16515790.

Use the most applicable Labour Operation from the Canadian Labour Time Guide.

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.