Daytime Running Lamp: Testing and Inspection

LH vehicles built for use in Canada are equipped with a Daytime Running Lamp (DRL) system. The DRL system operates the headlamp high beams at reduced power with the headlamp high beam and low beam switch OFF and the ignition switch in the run position. In addition, the park brake must be disengaged and the brake fluid level switch must be open for the headlamps to operate in the DRL mode. The DRL system is controlled by the Daytime Running Lamp Module attached to the Junction Block on the left side of the instrument panel. The DRL module overrides the headlamp switch when the headlamps are turned OFF. The headlamps operate normally when the headlamps are turned ON.

The Daytime Running Light Module (DRL Module) is controlled by inputs received from the ignition switch and High or Low Beam Headlamp relays, Park Brake switch, and the Brake Fluid Level switch.