Fog/Driving Lamp: Description and Operation

FRONT FOG LAMPS
When the front fog lamp switch is pressed, the instrument panel module (IPM) Front Fog Lamp Switch Input is grounded. In response to this input the IPM sends a class 2 message to the dash integration module (DIM) changing the state of the front fog lamps. The state of the front fog lamps will remain the same until the front fog lamp switch is pressed even between ignition cycles. Battery positive voltage (B+) is supplied at all times from the underhood fuse block FOG/DRL Fuse to the FOG LP relay switch. Battery positive voltage (B+) is supplied with the ignition switch in the ON position to the FOG LP relay coil. The FOG LP relay is located in the underhood fuse block. When the front fog lamp state is on the DIM grounds the FOG LP relay coil. With the ignition switch in the ON or START position the FOG LP relay coil is energized and the switch contact closes. Battery positive voltage (B+) is supplied to the LH and RH front fog lamps. The LH and RH front fog lamps are both permanently grounded so both front fog lamps have power and ground and then light. When the front fog lamps are on the park lamps will also light. Refer to Exterior Lights Circuit Description.