BMW F02 - HBL Filter

HBL Filter
The HBL filter is fitted to suppress interference pulses from the additional brake light
during radio reception. HBL stands for high-level brake light (third brake light).
A pulse-modulated signal (PWM) activates the third brake light. This kind of activation
(PWM rectangular signal) can cause high-frequency interference. This is especially
common with AM reception. The reason for this is that the audio information is contained
in the amplitudes in the AM signal.
Index Explanation
1
Rejector circuit on right side
Terminal 30, rear window:
lower section of rear window
2
Threaded ground connection
to vehicle body
3
Rejector circuit on right side
Terminal 30, connection,
vehicle wiring harness
Index Explanation
1
HBL filter - connection to additional brake
light and for powering the diversity
module with antenna amplifier
2
Securing screw with ground connection
3
HBL filter, connection to vehicle wiring harness
Right side antenna amplifier
HBL (high level brake light) filter
83
F01 Audio Systems