BMW DTC P221A – NOx Sensor 1/2 Correlation (Bank 1)
DTC P221A meaning on BMW
The DTC P221A code for BMW indicates a NOx (nitrogen oxide) sensor 1/2 correlation issue on Bank 1. This means that there is a discrepancy between the readings of the two NOx sensors located in Bank 1 of the vehicle.
BMW DTC P221A symptoms
Some common symptoms associated with the DTC P221A code on a BMW may include:
- Check Engine Light illuminated
- Reduced engine performance
- Increased fuel consumption
- Failed emissions test
BMW DTC P221A causes
The DTC P221A code on a BMW can be triggered by various factors, including:
- Faulty NOx sensor 1 or 2
- Wiring or connector issues
- Exhaust system leaks
- Engine misfire
BMW DTC P221A seriousness
While the DTC P221A code may not cause immediate drivability issues, it is important to address it promptly to prevent potential damage to the vehicle’s emissions system and ensure compliance with environmental regulations.
How to diagnose DTC P221A on BMW
Diagnosing the DTC P221A code on a BMW typically involves:
- Using a diagnostic scanner to retrieve the fault codes
- Inspecting the NOx sensors and their wiring for any visible damage
- Performing a sensor test to check the functionality of the NOx sensors
- Checking for exhaust leaks or other related issues
How to fix DTC P221A on BMW
To fix the DTC P221A code on a BMW, you may need to:
- Replace the faulty NOx sensor 1 or 2
- Repair any damaged wiring or connectors
- Address any exhaust system leaks
- Clear the fault codes and reset the Check Engine Light
How to erase DTC P221A on BMW
To erase the DTC P221A code on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the vehicle’s ECU. Once the codes are cleared, the Check Engine Light should turn off. It is important to ensure that the underlying issue causing the fault code has been addressed before clearing the codes.
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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