Possible causes

– Faulty Speed Sensor
– Speed Sensor harness is open or shorted
– Speed Sensor circuit poor electrical connection

When is the code detected?

Diagnostic trouble code is detected when Transmission Control Module (TCM) does not receive the proper voltage signal from the sensor.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Speedometer improper reading
– Possible shifting problems

P0720 BMW Description

The speed sensor detects the revolution of the idler gear parking pawl lock gear and emits a pulse signal. The pulse signal is sent to the Transmission Control Module (TCM) which converts it into vehicle speed.