BMW DTC P126D – Nox Sensor Signal Error at Start of Loading (Bank 2)
DTC P126D meaning on BMW
DTC P126D on a BMW indicates a Nox sensor signal error at the start of loading in Bank 2. This fault code is specific to the nitrogen oxide (NOx) sensor, which is responsible for monitoring and controlling the levels of NOx emissions from the vehicle’s exhaust system.
BMW DTC P126D symptoms
Symptoms of a DTC P126D on a BMW may include:
- Check Engine Light (CEL) illuminated on the dashboard
- Reduced engine performance or power
- Increased fuel consumption
- Failed emissions test
BMW DTC P126D causes
The common causes of a DTC P126D on a BMW include:
- Faulty NOx sensor
- Wiring or connector issues in the NOx sensor circuit
- Software or calibration issues
- Exhaust system leaks
BMW DTC P126D seriousness
Ignoring a DTC P126D on a BMW can lead to increased emissions, reduced fuel efficiency, and potential engine performance issues. It is important to address this fault code promptly to ensure the vehicle operates efficiently and meets emission standards.
How to diagnose DTC P126D on BMW
To diagnose a DTC P126D on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault code and any related codes
- Inspect the NOx sensor and its wiring for any visible damage or corrosion
- Check for exhaust leaks or other issues in the exhaust system
- Perform a sensor test using diagnostic equipment to verify sensor functionality
How to fix DTC P126D on BMW
To fix a DTC P126D on a BMW, you can try the following solutions:
- Replace the faulty NOx sensor with a new one
- Repair any damaged wiring or connectors in the NOx sensor circuit
- Update the vehicle’s software or calibration if necessary
- Address any exhaust system leaks or issues
How to erase DTC P126D on BMW
To erase a DTC P126D on a BMW, you can clear the fault code using a diagnostic scanner or by disconnecting the vehicle’s battery for a few minutes. However, it is recommended to address the underlying issue causing the fault code before clearing it to prevent it from reoccurring.
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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