Speedometer Head: Description and Operation

The car is equipped with an electronic speedometer. The ABS control module sends speed information continuously to pin 7 (14p).

This information is represented by a square wave which varies periodically between 8 V and 0 V, 29 times per wheel revolution.

When the wheels are stationary, the voltage may be either 8 V or 0 V.

This information controls the speedometer, odometer and trip odometer