P20AE – BMW DTC

BMW DTC P20AE – Reductant Metering Unit Temperature Sensor Circuit Low

DTC P20AE meaning on BMW

The Diagnostic Trouble Code (DTC) P20AE for BMW indicates a fault related to the Reductant Metering Unit Temperature Sensor Circuit registering a low voltage or resistance. This sensor is crucial for monitoring the temperature of the reductant metering unit, which is a part of the Selective Catalytic Reduction (SCR) system used to reduce emissions in diesel engines.

BMW DTC P20AE symptoms

Symptoms of the DTC P20AE on a BMW may include:

• Check Engine Light (MIL) illuminated
• Reduced engine performance
• Possible DEF (Diesel Exhaust Fluid) system warnings

BMW DTC P20AE causes

Common causes of the DTC P20AE on a BMW include:

• Defective Reductant Metering Unit Temperature Sensor
• Wiring or connector issues in the sensor circuit
• Faulty SCR system components

BMW DTC P20AE seriousness

The DTC P20AE should not be ignored as it can lead to increased emissions and potential engine performance issues. While the vehicle may still be operable, it is recommended to address this fault promptly to ensure proper emissions control and engine efficiency.

How to diagnose DTC P20AE on BMW

To diagnose the DTC P20AE on a BMW, you can follow these steps:

1. Use a diagnostic scanner to retrieve the fault codes and confirm the presence of P20AE.
2. Inspect the Reductant Metering Unit Temperature Sensor and its wiring for any visible damage or corrosion.
3. Check the sensor’s resistance and voltage values to determine if it is functioning within specifications.
4. Perform a comprehensive inspection of the SCR system components for any other potential issues.

How to fix DTC P20AE on BMW

To fix the DTC P20AE on a BMW, you can consider the following actions:

1. Replace the Reductant Metering Unit Temperature Sensor if it is found to be faulty.
2. Repair any damaged wiring or connectors in the sensor circuit.
3. Clear the fault codes using a diagnostic scanner after completing the repairs.
4. Perform a test drive to ensure the issue has been resolved and the MIL is no longer illuminated.

How to erase DTC P20AE on BMW

To erase the DTC P20AE on a BMW, follow these steps:

1. Connect a diagnostic scanner to the vehicle’s OBD-II port.
2. Access the scanner’s menu to clear the fault codes stored in the system.
3. Confirm the deletion of the DTC P20AE by checking for any remaining codes.
4. If the MIL is no longer illuminated and there are no active fault codes, the DTC P20AE has been successfully erased.

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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