Quote:
Originally Posted by AndrewC1989
Quote:
Originally Posted by Poochie
The "bulb check" circuit in these vehicles was a holdover from when BMW used incandescent lights, which was implemented to detect what it believes to be a burn out light bulb.
The bulb check system doesn't distinguish between LED or incandescent bulbs power draw, however, in BMW's infinite wisdom, decided to leave the "warm bulb check" active with their LED setup, making the system assume that there an incandescent bulb outage, when it in fact the LEDs are fine, just merely using less current, by nature.
|
Stupid question: what's the difference between a warm and cold check? |
Hey,
So for "Cold Bulb Checks," the bulbs are switched on by a short current pulse
without the bulb being powered up.
"Warm Bulb Checks"
while the lights are powered on, the hot monitoring measures the individual power outputs, to assist in detection of any short and open circuits. A faulty incandescent bulb is detected within approx. 2 seconds.
For the record, LEDs are not
cold-monitored, as LEDs react too quickly and would light up or strobe, when powered off.