4.27.1 Description

Two checks are performed on the vehicle speed signal. The first check monitors for the loss of any of the ABS wheel speed sensor signals. If any of the signals are not available for longer than a predefined time a failure is registered. The second check compares the vehicle speed transmitted by the ABS control module and the vehicle speed calculated by the ECM (using data from the transmission output shaft speed sensor). If the transmitted and calculated speeds do not match for longer than a predefined time a failure is registered.

Fig 1: Vehicle Speed Signal (P0500, P0501, P0721)

Courtesy of JAGUAR CARS, INC.