Fog/Driving Lamp: Description and Operation

FRONT FOG LAMPS
When the ignition switch is in the RUN position, battery positive voltage (B+) is applied to the coil of the fog lamp relay in the engine compartment relay center from the IGN 1 Fuse via CKT 439 (BRN). Battery positive voltage (B+) is applied at all times to the switch of the fog lamp relay from the FOG Fuse via CKT 1640 (ORN). When the front fog lamps switch is enabled, the instrument cluster front fog lamps input is grounded through the headlamp switch via CKT 192 (ORN). In response to this input, the instrument cluster sends a request via the Class 2 serial data line to the body control module (PZM) to activate the front fog lamps. The PZM provides ground for the coil via CKT 1317 (DK GRN/WHT). The coil is energized closing the switch contacts. Battery positive voltage (B+) is then applied via CKT 34 (PPL) to the LH front fog lamp, RH front fog lamp and the front fog lamps ON indicator. The PZM also activates the park lamps when the front fog lamps are on. If the front fog lamps are enabled and the high beams or flash-to-pass are activated, the front fog lamps will be temporarily disabled for as long as the high beams or flash-to-pass are enabled. The park lamps will remain on during this period.

REAR FOG LAMPS
When the ignition switch is in the RUN position, battery positive voltage (B+) is applied to the coil of rear fog lamp relay from the IGN 1 Fuse via CKT 439 (BRN). With the park lights on. battery positive voltage (B+) is applied to the switch of rear fog lamps relay from the RT PARK Fuse via CKT 9 (BRN). When the rear fog lamp switch is enabled, the instrument cluster rear fog lamps input is grounded through the headlamp switch via CKT 187 (LT BLU). In response to this input, the instrument cluster sends a request via the Class 2 serial data line to the PZM to activate the rear fog lamps. The PZM provides ground for the coil via CKT 1977 (YEL). The coil is energized closing the switch contacts. Battery positive voltage (B+) is then applied via CKT 122 (RED) to the LH rear fog lamp, RH rear fog lamp and the rear fog lamps ON indicator.