BMW DTC P126C – Nox Sensor Signal Error at Start of Loading (Bank 1)
DTC P126C meaning on BMW
The DTC P126C error code on a BMW indicates a Nox sensor signal error at the start of loading in Bank 1. This means that there is an issue with the signal being received from the Nox sensor located in Bank 1 of the vehicle’s exhaust system.
BMW DTC P126C symptoms
Symptoms of the BMW DTC P126C error code may include:
- Check Engine Light (MIL) illuminated
- Reduced engine performance
- Increased fuel consumption
- Possible rough idling or misfiring
BMW DTC P126C causes
Common causes of the BMW DTC P126C error code include:
- Failed Nox sensor in Bank 1
- Wiring or connector issues related to the Nox sensor
- Exhaust system leaks or damage
- Software or calibration issues
BMW DTC P126C seriousness
The DTC P126C error code should not be ignored as it can lead to increased emissions, reduced fuel efficiency, and potential engine performance issues. It is recommended to address this issue promptly to prevent further damage to the vehicle.
How to diagnose DTC P126C on BMW
To diagnose the DTC P126C error code on a BMW, a mechanic may perform the following steps:
- Use a diagnostic scanner to retrieve the fault codes
- Inspect the Nox sensor in Bank 1 for any physical damage
- Check the wiring and connectors for any signs of wear or corrosion
- Perform a visual inspection of the exhaust system for leaks or damage
- Verify software and calibration settings
How to fix DTC P126C on BMW
To fix the DTC P126C error code on a BMW, the following steps may be taken:
- Replace the Nox sensor in Bank 1 if it is found to be faulty
- Repair or replace any damaged wiring or connectors
- Address any leaks or damage in the exhaust system
- Update software or recalibrate the system as needed
How to erase DTC P126C on BMW
Once the underlying issue causing the DTC P126C error code has been resolved, the code can be erased using a diagnostic scanner. This will clear the code from the vehicle’s memory and turn off the Check Engine Light. It is important to ensure that the repair has been successful before clearing the 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
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.