Circuit Description
WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
The BCM provides control for the L DRL relay circuit. The BCM grounds the L DRL relay control circuit in order to energize the L DRL relay and turn ON the LF turn signal This allows the LF turn signal to be used for DRL, UTD, and approach lighting functions. The BCM monitors the voltage level on the L DRL relay control circuit. When the BCM commands the relay ON, the voltage level on the L DRL relay control circuit should be low. When the relay is OFF, the voltage on the L DRL relay control circuit should be high. If the BCM detects a voltage level other than expected, a malfunction is present and a DTC will set.