FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Ultralight Sensor

GENERAL INFORMATION
Ultralight System
The Ultralight system turns the instrumentation and exterior illumination lamps ON when the ambient light levels are low and OFF when light levels are high. Ultralight is controlled by the Body Control Module (BCM). With the headlamp switch in the AUTO position, the BCM will control the headlamp, parking, side marker, tail and instrumentation lamps based on ambient light levels. Ambient light levels are monitored by the BCM using the automatic temperature control system Sunload Sensor, located on the top of the instrument panel cover. Ambient light readings are averaged to limit cycling the lamps - ON and OFF when passing through areas with varying light levels. Ultralight will only function when the engine is running. When the headlamp switch is in the AUTO position (Ultralight mode), the Headlamp Time Delay system will function when the ignition is switched OFF.