BMW DTC P20AF – Reductant Metering Unit Temperature Sensor Circuit High
DTC P20AF meaning on BMW
DTC P20AF on a BMW indicates a fault with the Reductant Metering Unit Temperature Sensor Circuit. This fault code is triggered when the Engine Control Module (ECM) detects a high voltage condition in the circuit related to the temperature sensor in the reductant metering unit.
BMW DTC P20AF symptoms
Symptoms of DTC P20AF on a BMW may include:
- Check Engine Light illuminated
- Reduced engine performance
- Possible DEF (Diesel Exhaust Fluid) system warnings
BMW DTC P20AF causes
Common causes of DTC P20AF on a BMW include:
- Faulty Reductant Metering Unit Temperature Sensor
- Wiring or connector issues in the sensor circuit
- ECM software issues
BMW DTC P20AF seriousness
The seriousness of DTC P20AF on a BMW lies in the potential impact on emissions control and engine performance. Ignoring this fault code can lead to increased emissions and potential engine damage over time.
How to diagnose DTC P20AF on BMW
To diagnose DTC P20AF on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault codes
- Inspect the Reductant Metering Unit Temperature Sensor and its wiring for any visible damage
- Check the sensor’s resistance and voltage values according to manufacturer specifications
- Perform a visual inspection of the reductant system components for any signs of leaks or damage
How to fix DTC P20AF on BMW
To fix DTC P20AF on a BMW, you can try the following:
- Replace the Reductant Metering Unit Temperature Sensor if faulty
- Repair any damaged wiring or connectors in the sensor circuit
- Clear the fault codes and perform a test drive to ensure the issue is resolved
How to erase DTC P20AF on BMW
To erase DTC P20AF on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the ECM memory. After clearing the codes, it is recommended to perform a test drive to verify that the issue has been resolved.
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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