BMW DTC P203C – Reductant Level Sensor ‘A’ Circuit Low
DTC P203C meaning on BMW
DTC P203C for BMW refers to the Reductant Level Sensor ‘A’ Circuit Low. This diagnostic trouble code indicates that the reductant level sensor circuit for the AdBlue system is reporting a low voltage signal, which may be caused by various issues affecting the sensor’s operation.
BMW DTC P203C symptoms
Symptoms of DTC P203C on a BMW may include the check engine light being illuminated on the dashboard, reduced engine performance, and potential warnings related to the AdBlue system or emissions control system.
BMW DTC P203C causes
The causes of DTC P203C on a BMW can vary and may include issues such as a faulty reductant level sensor, wiring problems in the sensor circuit, a malfunctioning AdBlue system, or issues with the engine control module (ECM) that interprets the sensor data.
BMW DTC P203C seriousness
While DTC P203C may not cause immediate drivability issues, it is important to address this fault as it can lead to increased emissions and potential non-compliance with environmental regulations. Ignoring this fault could also result in the vehicle failing emissions tests.
How to diagnose DTC P203C on BMW
To diagnose DTC P203C on a BMW, a mechanic would typically use a diagnostic scanner to retrieve the fault code and then perform further testing on the reductant level sensor, wiring, and related components to identify the root cause of the low circuit voltage.
- Use a diagnostic scanner to read the fault code
- Inspect the reductant level sensor and its wiring for any visible damage or corrosion
- Test the sensor’s resistance and voltage output
- Check the AdBlue system for proper operation
- Verify the ECM is receiving and interpreting sensor data correctly
How to fix DTC P203C on BMW
Fixing DTC P203C on a BMW typically involves addressing the underlying cause of the low circuit voltage in the reductant level sensor system. Depending on the specific issue, potential fixes may include:
- Replacing the reductant level sensor
- Repairing or replacing damaged wiring in the sensor circuit
- Resetting the AdBlue system and ensuring proper fluid levels
- Updating the ECM software or replacing the ECM if necessary
How to erase DTC P203C on BMW
Once the underlying issue causing DTC P203C on a BMW has been resolved, the fault code can be cleared using a diagnostic scanner. This process typically involves accessing the vehicle’s ECM, selecting the option to clear fault codes, and confirming the deletion of the stored DTC P203C code.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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