Filament monitor, front lights: Notes

Fig 1: Communication Diagram - Filament Monitor (Front Lights)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Circuit Diagram - Filament Monitor (Front Lights)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The SID unit receives information on headlamp functionality from the filament monitor.

The SID unit sends B+ to the filament monitor via pin 10. If a headlamp bulb is faulty, the filament monitor output will be grounded.

The SID unit uses the information for a CHECK message (3 second delay). See CHECK MESSAGES  .