The low beam headlamps operate at reduced intensity when in daytime running lamps (DRL) mode. The DRL relay is soldered into the underhood fuse block circuit board. The ground circuit to the switch side or the DRL relay has a resistor in-line to reduce the intensity of the low beam headlamps for DRL operation. The body control module (BCM) receives a signal from the ambient light sensor indicating a low or high ambient outside light level. Under daylight conditions the BCM grounds the DRL relay control circuit energizing the DRL control relay. The now closed relay supplies ground directly to the low beam headlamps now illuminate with reduced intensity. The DRL relay is ground at G203. Any time the headlamps are illuminated the DRL will not illuminate. Manual park lamps do not effect DRL operation.

An open/high resistance in the instrument panel I/P can cause the DRL indicator to become inoperative

Schematic Reference

Headlights/Daytime Running Lights (DRL) Schematics

Connector End Views

Lighting Systems Connector End Views

Electrical Information Reference

Scan Tool Reference

Ignition ON, the headlamp switch in the AUTO position. Observe the headlamps, the headlamps should be ON.

1. Ignition OFF, disconnect the harness connector at the turn signal multifunction switch terminals C1 pins 4 and 2.
2. Ignition ON, test for less than 1 ohm of resistance between the low reference circuit and ground with the DRL ON.

⇒	If greater than 1 ohm, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the turn signal multifunction switch.

3. Test for battery voltage between the supply voltage circuit and ground.

⇒	If battery voltage is not found, test the supply voltage circuit for a short to ground or an open/high resistance.

4. If all circuits test normal, replace the I/P.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for I/P replacement, setup, and programming