Daytime Running Lamp: Description and Operation

CANADIAN VEHICLES ONLY

This Daytime Running Lamps (DRL) System uses the Fog Lamps for Daytime Running Lights. When the Ignition Switch is in "RUN" with the park brake released, and the Headlamps are off, the DRL feature is on.

Voltage is supplied to the DRL Relay Coil and contacts at all times from the "HEAD" Fuse. When the DRL Control Module sees an open circuit 381 (R/W), indicating that the Park Brake is released, and 0 volts at circuit 261 (W), indicating that the Headlamps are off, it applies a ground to the DRL Relay Coil via circuit 272 (GN).

The DRL Relay energizes, applying battery voltage to the Fog Lamps. When the Headlamps are turned on, voltage is applied the DRL Control Module via circuit 261. The DRL Control Module then removes ground from circuit 272 (GN), de-energizing the DRL Relay. The Fog Lamps turn off.

Applying the Park Brake also disables the DRL System by applying a ground signal to the module via circuit 381 (R/W). The diode shown inside the DRL Control Module prevents low brake fluid level from disabling the DRL System. The Powertrain Control Module (PCM) receives a DRL on signal via circuit 272.