Principles of Operation

Fog Lamps

Principles of Operation

NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).

The SJB (Smart Junction Box) monitors the headlamp switch position by sending a voltage signal to the headlamp switch. When the fog lamp switch is engaged, the voltage signal is routed to ground.

The fog lamps can be turned on when the following conditions are met:

- The ignition switch is in the RUN or START position.

- The low beam headlamps or the parking lamps are on.

- The high beams are not on.

When the SJB (Smart Junction Box) receives an input from the headlamp switch indicating a request for the fog lamps, the SJB (Smart Junction Box) provides voltage to the fog lamp relay. When the fog lamp relay is energized, voltage is routed to the fog lamps.