Lamp Monitoring
Lamp monitoring on the E46 is a function of the LSZ control module. The following lamps are monitored in both the hot and cold states:
- High/Low Beams
- Brake Lights - Left/Right
- Turn Signal Lights
- Tail Lights
- Parking Lights
- Side Marker Lights
- License Plate Lights
Hot monitoring takes place when the lights are switched by monitoring the current flow through the lamp filaments.
Cold monitoring takes place by the LSZ when the lights are switched off. The LSZ will briefly activate the lighting circuits and check for current flow through the lamps. The lights are not switched on long enough to illuminate the bulbs.
If the LSZ detects a defective bulb, a signal is sent to the instrument cluster and the warning is posted in the Check Control pictogram.