Daytime Running Lamps (DRL)

Overview 

The DRL system consists of:

• Low beams (halogen headlamps)
• Turn lamps (High Intensity Discharge (HID) headlamps)
• BCM-B

The DRL system operates the low beam headlamps at a reduced intensity (vehicles with halogen headlamps) or the front turn lamps at full intensity (not flashing) (vehicles with HID headlamps). When enabling the DRL on vehicles that were not equipped with DRL from the factory, using the scan tool, the DRL operates the front turn lamps at full intensity (not flashing) regardless of headlamp options.

System Operation 

System Diagram 

Courtesy of FORD MOTOR COMPANY

Daytime Running Lamps (DRL) 

The DRL system utilizes the existing circuitry and components from the headlamp or the turn lamp system.

The BCM-B monitors the ignition status (ignition switch for vehicles without Intelligent Access (IA) or the RFA module for vehicles With Intelligent Access), the headlamp switch and autolamp status, and the transmission range status from the PCM.

Based on the input, the BCM-B activates the DRL.

The DRL are activated when:

• the ignition is in RUN,
• the headlamps have not been turned on by the autolamp system or the headlamp switch, and
• the transmission is not in PARK.