Principles of Operation

Stoplamps

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 input from the stoplamp switch. When the brake pedal is applied, voltage is routed to the SJB (Smart Junction Box) and the high mounted stoplamp. When the SJB (Smart Junction Box) detects the voltage from the stoplamp switch, the SJB (Smart Junction Box) provides voltage to the rear stoplamps.

On vehicles equipped with adaptive cruise control, the adaptive cruise control stoplamp relay is wired in parallel with the stoplamp switch output circuit. When the brake pedal is applied, voltage from the stoplamp switch is routed through the adaptive cruise control stoplamp relay before going to the SJB (Smart Junction Box) and the high mounted stoplamp. This allows the ABS module to activate the stoplamps for conditions related to the adaptive cruise control system. For details regarding the adaptive cruise control system, refer to Cruise Control.