Theory Of Operation
WARNING: This page is about a different car, the 2020 Jeep Renegade. However, it is still accessible from the selected car via links, so may be relevant.
The Daytime Running Lamps (DRLs) illuminate when the engine is running, the Parking Brake is released and the Headlamps are off, or in the AUTO position. When the Body Control Module (BCM) receives a CAN Bus message from the PCM, indicating the engine is running, a hard-wired input from the Headlamp Switch, indicating the Headlamp Switch is Off, or in the AUTO position, and a CAN Bus message from the Antilock Brake System (ABS) Module, indicating that the Parking Brake is released, the BCM will provide voltage to the Left and Right DRLs through the DRL Lamp Driver circuits.