Medium Duty Operator's Manual - Peterbilt Motors Company

DASH- AND DOOR-MOUNTED FEATURES
CONTROLS AND DISPLAY
release the parking brake. If the headlight switch is ON,
the DRL system is overridden, and headlights operate
normally.
WARNING! Do not use daytime running lights
(DRL) during periods of darkness or reduced
visibility. Do not use DRL as a substitute for
headlights or other lights during operations
that require lighting of your vehicle. Doing so
could lead to an injury accident.
Daytime Running Lights
On vehicles equipped with the Daytime Running Light
(DRL) system, the low beam headlights are turned ON
automatically at reduced brightness (to conserve headlamp
life).
If the headlight switch is turned OFF, the DRL system
engages automatically after the engine starts and you
CAUTION: On vehicles equipped with daytime
running lights (DRL), the high-beam headlamps
go on automatically at reduced brightness if the
engine is running and the headlamp switch is
turned off. The daytime running lights are turned
off automatically while the parking brake is
engaged. If the headlamp switch is turned on, the
DRL system is overridden & headlamps operate
normally.
– 50 – Y53-6008A Medium Duty (R05/09)