Principles of Operation
WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
The SJB controls the Daytime Running Lamps (DRL) by using various inputs to determine whether or not the DRL should be illuminated. These inputs include:
- Ignition switch position
- Headlamp switch position
- Headlamps on or off
- Transmission gear selection
- Parking brake input status
The DRL are not a programmable parameter for this vehicle.
When the DRL is active, the SJB energizes the fog lamp relay. This illuminates the fog lamps at full intensity.