Exterior Lamps - Operation

OPERATION

AUTOMATIC HEADLAMP SYSTEM

Automatic headlamps are controlled by the Cab Compartment Node (CCN). With the headlamp switch in the AUTO position, the CCN controls the headlamp, parking, side marker, tail and instrumentation lamps based on ambient light levels. Ambient light levels are monitored by the CCN using the ambient light signal present. Ambient light readings are averaged to limit cycling the lamps on and off when passing through areas with varying light levels. The automatic headlamps only function when the engine is running higher than 300 RPM. When the headlamp switch is in the AUTO position (Automatic mode), the headlamp time delay system functions when the ignition switch is placed in any position other than run/start.

DAYTIME RUNNING LAMPS

Power is reduced using Pulse-Width Modulation (PWM) to the high beams, where by power is switched on and off rapidly instead of remaining on continuously. The duration and interval of the power pulses is programmed into the Integrated Power Module (IPM).

HEADLAMP TIME DELAY SYSTEM

The headlamp time delay system is activated by turning the headlamps on (high or low beam) while the engine is running, turning the ignition switch off, and then turning the headlamp switch off. The Cab Compartment Node (CCN) will allows the headlamps to remain on for 90 seconds (configurable) before they automatically turn off. If the key is in the ignition during the headlamp time delay mode, both the headlamps and park lamps (including panel dimming) will be on.

If the headlamp switch is in the auto headlamp position, the headlamps are on due to the night signal from the ambient light sensor and the ignition switch is in any position other than run/start, the CCN enters a 90 second (configurable) auto headlamps time delay mode. If the key is in the ignition during the headlamp time delay mode, both the headlamps and park lamps (including panel dimming) will be on. If the key is not in the ignition, only the headlamps are on. The CCN allows the headlamps to remain ON for 90 seconds before they automatically turn off.