Vehicle Speed Sensor: Description and Operation

The Vehicle Speed Signal is connected to pin 50 of the Motronic control module, the signal is directional IN only (PIN 50 - INPUT ONLY).

The vehicle speed signal is information about the current vehicle speed and is supplied to the control module by the speedometer.

The signal is used for idle air control (active below 4 mph) and A/C compressor cut-out (also compare with pin 6).

Self-diagnosis:

^ Self-diagnosis (OBD) recognizes the fault "no signal" (Diagnostic Trouble code 1231).