The Quick Answer above is the generic definition. What follows is what is documented for the BMW models that log P0502, checked against manufacturer data and owner reports.
DTC/P0502·BMW
P0502 on BMW: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeverityNot safe to driveBMW
P0502 on a BMW 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.
Repair cost on BMW€60 - €650
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BMW 3 Series
2005-2024On E90 and F30 3 Series, P0502 typically follows a complete ABS wheel speed sensor failure, often at the rear axle. Iron particles from the bearing collect on the sensor magnet and eventually short the signal to ground. BMW recommends inspecting the bearing whenever a rear sensor is replaced.
What causes P0502 on a BMW?
Beyond the generic causes listed on the main P0502 page, these are the documented BMW-specific patterns:
BMW 3 SeriesRear ABS wheel speed sensor failure with short to ground
BMW 3 SeriesIron debris from worn rear bearing contaminating the sensor
How to diagnose P0502 on a BMW with OBD2
Follow these steps to pinpoint the root cause of P0502:
- Read all stored codes. Companion ABS wheel speed codes (C-codes) usually point directly to the failed circuit
- 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
- 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
- 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
- If the wiring and sensor are healthy, inspect the reluctor ring for missing teeth, cracks, or a sheared press fit
How much does P0502 cost to fix on a BMW? (EUR)
Estimated repair costs for P0502 in EUR, compiled across makes. Expect BMW parts and labour towards the upper end of each range.
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0502 on BMW
These codes commonly cluster with P0502 on BMW vehicles:
Looking for the full P0502 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0502 guideSkanyx · BMW
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