KlaroFault codeP0502
MODERATEVehicle Speed Sensor Circuit Low Input
What this code means
Vehicle Speed Sensor Circuit Low Input.
P0502 is a generic code: it means the same thing on every make. P0502 belongs to family P05xx — Idle speed and vehicle speed control. Its page explains how to read a code and groups all its codes by part.
Type of fault
The control unit reads a voltage on this circuit below its expected range. Usual causes: a wire shorted to ground or broken, a corroded or loose connector, or the component itself. Check the wiring and connector before replacing the part — that is where many of these faults turn out to be.
Vehicle speed sensor
The speed sensor tells the control units how fast the car is going, from the gearbox output or the wheel speed sensors of the ABS. Engine, gearbox, speedometer and cruise control all rely on it.
What you notice
A speedometer that stops or jumps, cruise control not working, erratic shifts on automatic gearboxes, sometimes an unstable idle.
How to check it
Check the connector on the gearbox or the wheel sensor, and the wiring for chafing. In Klaro, the vehicle speed should follow the speedometer smoothly; a speed that drops to zero while driving points to the sensor or its circuit. ABS faults on the dashboard point to the wheel sensors.
Watch it live in Klaro
With an OBD2 adapter plugged in, these live readings show the part at work, when your car reports them:
- Vehicle speed
- Engine RPM
What to do
Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.
Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →
How to read this code
- PPowertrain
- 0standardised code
- 5Idle speed and vehicle speed control
- 02P0502
