Vehicle Speed Sensor: Description and Operation
CONNECTIONThe Vehicle Speed Signal is connected to pin B 9 of the Engine Control Module, the signal is directional IN only (PIN B 9 - INPUT ONLY).
SIGNAL SOURCE
The vehicle speed signal is information about the current vehicle speed and is supplied to the Engine Control Module by the speedometer.
SIGNAL USAGE
The signal is used for idle air control (active below 4 mph) and A/C compressor cut-out (also compare with pin C 10).
Self-diagnosis:
^ Self-diagnosis (OBD) recognizes the fault "no signal".