Operation CHARM: Car repair manuals for everyone.

Principles of Operation

PRINCIPLES OF OPERATION

NOTE: The smart junction box (SJB) is also known as the generic electronic module (GEM).

The DRL feature operates the low beam headlamps at a reduced intensity when the ignition switch is in the RUN position, the headlamps are not on from any other input, and the transmission is not in PARK (P).

The SJB controls the 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