P0502 : Vehicle Speed Sensor "A" Circuit Low Input

P0502 means the ECU is detecting a voltage on the vehicle speed sensor circuit that is lower than expected, typically because the signal wire is shorted to ground, the sensor has failed open, or the connector has lost contact. On vehicles that use the ABS wheel speed sensors as the primary speed input, P0502 usually accompanies an ABS wheel speed code.

P0502 est un code defaut lie a electrique, classe en gravite moderate. Lorsque le calculateur de ton vehicule detecte cette condition, il enregistre P0502 et allume le voyant moteur.

Si ton vehicule a declenche P0502, tu peux remarquer un ou plusieurs de ces symptomes :

• Speedometer reads zero even while driving
• ABS and traction control warning lights on
• Cruise control will not engage
• Automatic transmission shifts harshly or stays in a single gear
• Check engine light on

Voici les causes les plus courantes de P0502, classees selon la probabilite qu'elles soient en cause :

Non, regle ca immediatement. The ECU is reading a vehicle speed signal that is below the expected threshold, which usually means zero signal or a shorted-to-ground circuit. Speedometer, ABS, and transmission shift quality are affected. Drive only as far as needed to reach a workshop.

Suis ces etapes pour identifier la cause profonde de P0502 :

1. Read all stored codes. Companion ABS wheel speed codes (C-codes) usually point directly to the failed circuit
2. Locate the suspect sensor and inspect the connector for water, corrosion, and damaged pins. Reseat the connector and clear the code to see if it returns
3. With ignition off, measure resistance from the sensor signal pin to chassis ground. A near-zero reading confirms a short to ground in the wiring or the sensor
4. Backprobe the sensor connector with the engine running and the wheels spinning. A Hall-effect sensor should switch between roughly 0 V and 5 V; a magnetic sensor should produce a small AC waveform that grows with speed
5. If the wiring and sensor are healthy, inspect the reluctor ring for missing teeth, cracks, or a sheared press fit

Les couts de reparation de P0502 varient selon la cause profonde et ton vehicule. Voici des estimations courantes :

P0502 se comporte differemment selon ton vehicule. Selectionne ta voiture ci-dessous pour des causes propres au modele, les problemes connus et des estimations de couts ajustees :

Ces codes apparaissent souvent avec P0502 ou indiquent des problemes connexes :