Originally Posted by shadye90
When you installed the ultrasonic modlue didnt you have to cut open the slits in order for the sensor signals to pass through because on a e90 w/o the factory alarm the slits are not cut out..
There's a TSB on this. Car should have come from the factory with a slotted rear light module cover. Plenty of members here have taken this TSB printout to their dealers and had them install the correct slotted cover for free. See the first TSB here to see what I'm talking about -