Principles of Operation
WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. 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 (automatic transaxle)
- Parking brake applied or released (manual transaxle)
When the DRL is active, the SJB provides a pulse-width modulated voltage to the low beam headlamps. This illuminates the headlamps at a reduced intensity.
The SJB can be configured to turn the DRL on for this vehicle. Refer to MODULE CONFIGURATION for additional information on this programmable parameter.