Engine Speed Sensor: Description and Operation

DME of the 911 Carrera 4 works with one new inductive sender for speed and reference mark information. A gear ring is machined on the flywheel for this purpose and has 60 teeth. Two of these teeth have openings for production of the reference mark signal. The reference mark signal is designed for 84° before TDC.

This inductive sender is designed for a higher speed range and a larger disturbance interval. The distance of the sender to the flywheel's gear ring is adjustable and must be 0.8 ± 0.2 mm (0.032 ± 0.08 in).