P0502 - Vehicle Speed Sensor 'A' Low Input
- Vehicle speed sensor harness or connectors is open or shorted
- Vehicle speed sensor circuit poor electrical connection
- Faulty Engine Control Module (ECM)
- Speedometer may not work properly
- Transmission shifting problem
The vehicle speed sensor outputs a 4 pulse signal for every revolution of the rotor shaft, which is rotated by the transmission output shaft via the driven gear. After this signal is converted into a more precise rectangular waveform by the waveform shaping circuit inside the combination meter, it is then transmitted to the Engine Control Module (ECM). The ECM determines the vehicle speed based on the frequency of these pulse signals.
Any information is appreciated. Thanks