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Filament monitor

Filament monitor

Dipped beam filament monitor


Main beam filament monitor


Daylight driving light filament monitor


The filament monitor 228b is located in the engine bay (relay box). It detects any break in the circuit to the lamps by measuring the current in the circuit. In the event of an open circuit, the filament monitor pin 9 grounds pin 23 of the SID unit. SID displays the message FRONT LIGHT FAILURE.

Parking light filament monitor

4D


5D


Brake light filament monitor

4D


5D


In TWICE, the current to each pin passes through a shunt resistor for that pin. In the event of filament failure, SID puts a fault message onto the bus. The control module generates an audible signal and puts the message REAR LIGHT FAILURE onto the display.