Tribute 4WD L4-2.3L Hybrid (2008)
Brake Lamp: Description and Operation
STOPLAMPS
Principles of Operation
NOTE: The smart junction box (SJB) is also known as the generic electronic module (GEM).
The SJB monitors the input from the stoplamp switch. When the brake pedal is applied, voltage is routed to the SJB and the high mounted stoplamp. The
SJB then supplies voltage to the stoplamps.
Field-Effect Transistor (FET) Protection
The SJB utilizes a FET protective circuit strategy for many of its outputs (for example, the headlamp output circuit). Output loads (current level) are
monitored for excessive current (typically short circuits) and are shut down (turns off the voltage or ground provided by the module) when a fault is
detected. A continuous DTC is stored at that time for the fault. The circuit will then reset after a customer demand of the function (switching the
component on, battery saver being energized). When an excessive circuit load occurs several times, the module shuts down the output until a repair
procedure is carried out. At the same time, the continuous DTC that was stored on the first failure will not clear by a command to clear the continuous
DTCs. The module will not allow this code to be cleared or the circuit restored to normal operation until a successful on-demand self-test proves that the
fault has been repaired. After the on-demand self-test has successfully completed (no on-demand DTCs present), the continuous DTC will have been
cleared and the circuit function will return.
Each circuit has three predefined levels of short circuit tolerance established in the module based on each circuits' capability. When the first or second
level is reached, the continuous DTC associated with the circuit sets along with DTC B106E. These DTCs may be cleared using the Clear DTC
operation on the scan tool as long as the fault itself has been corrected. If any of the circuits are shorted past the third level, then B106F sets along with
the associated continuous DTC. This DTC cannot be cleared and the module must be replaced.
The SJB FET protected output circuits for the stoplamp system are for the LH rear stop/turn lamp output and the RH rear stop/turn lamp output circuits.
