Heavy Duty 971927807 Rear ABS Wheel Speed Sensor Fit Porsche Panamera On the Porsche 971 Panamera (and the 992 GT3), the wheel-speed pick-ups are carefully calibrated Hall sensors tucked into the wheel carrier, reading a multi-pole encoder ring buried in the hub. When metal shavings from the brake pads settle on the tip, the sealed plug works loose, or the bearing encoder throws a tooth, you get the ABS and PSM lamps, a speedo that flickers, and a wheel-speed fault that