BMW DTC P122D – NOx Sensor Circuit Shorted (Bank 2)
DTC P122D meaning on BMW
DTC P122D is a diagnostic trouble code that indicates a NOx (nitrogen oxide) sensor circuit shorted on Bank 2 in a BMW vehicle. This fault code is specific to the NOx sensor system, which is responsible for monitoring and controlling the levels of nitrogen oxides in the exhaust gases.
BMW DTC P122D symptoms
Symptoms of DTC P122D may include:
- Check Engine Light illuminated
- Reduced engine performance
- Increased fuel consumption
- Failed emissions test
BMW DTC P122D causes
Common causes of DTC P122D include:
- Short circuit in the NOx sensor circuit on Bank 2
- Faulty NOx sensor
- Wiring or connector issues
- ECU (Engine Control Unit) malfunction
BMW DTC P122D seriousness
DTC P122D should not be ignored as it can lead to increased emissions, reduced engine efficiency, and potential damage to the catalytic converter. It is important to address this issue promptly to ensure proper vehicle operation and compliance with emissions regulations.
How to diagnose DTC P122D on BMW
To diagnose DTC P122D, a mechanic may perform the following steps:
- Use a diagnostic scanner to retrieve the fault code
- Inspect the NOx sensor circuit on Bank 2 for any visible damage or short circuits
- Check the wiring and connectors for proper connection and continuity
- Test the NOx sensor for proper functionality
- Verify the ECU operation and communication with the sensor
How to fix DTC P122D on BMW
To fix DTC P122D, the following steps may be taken:
- Repair any damaged wiring or connectors in the NOx sensor circuit
- Replace the faulty NOx sensor on Bank 2
- If necessary, reprogram or replace the ECU
- Clear the fault code and perform a test drive to verify the repair
How to erase DTC P122D on BMW
To erase DTC P122D, a diagnostic scanner can be used to clear the fault code from the ECU memory. After the repair has been completed, the code can be erased to reset the Check Engine Light and ensure 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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