BMW DTC P122E – NOx Sensor Binary Oxygen Sensor Signal Circuit/Open (Bank 1)
DTC P122E meaning on BMW
DTC P122E indicates a fault with the NOx sensor binary oxygen sensor signal circuit on Bank 1 in a BMW vehicle. This fault typically means that there is an open circuit in the signal path of the NOx sensor, preventing the proper communication of data between the sensor and the engine control module.
BMW DTC P122E symptoms
Symptoms of DTC P122E in a BMW may include poor engine performance, decreased fuel efficiency, rough idling, and potentially an illuminated check engine light on the dashboard. Additionally, the vehicle may fail emissions testing due to increased NOx emissions.
BMW DTC P122E causes
The most common causes of DTC P122E in a BMW are a faulty NOx sensor, damaged wiring or connectors in the sensor circuit, or a malfunctioning engine control module. Environmental factors such as exposure to extreme temperatures or contaminants can also contribute to this fault.
BMW DTC P122E seriousness
While DTC P122E may not cause immediate harm to the vehicle, it can lead to decreased engine efficiency and increased emissions. Ignoring this fault can result in potential damage to the catalytic converter and other emission control components over time.
How to diagnose DTC P122E on BMW
To diagnose DTC P122E on a BMW, a mechanic would typically use a diagnostic scanner to retrieve the fault code and perform a visual inspection of the NOx sensor and its wiring. They may also conduct tests to check the sensor’s resistance and voltage output to determine if it is functioning correctly.
How to fix DTC P122E on BMW
Fixing DTC P122E on a BMW usually involves replacing the faulty NOx sensor, repairing any damaged wiring or connectors in the sensor circuit, or reprogramming the engine control module if necessary. It is important to address the root cause of the fault to prevent it from recurring.
How to erase DTC P122E on BMW
Once the underlying issue causing DTC P122E has been resolved, the fault code can be cleared using a diagnostic scanner. By erasing the code, the check engine light will turn off, indicating that the fault has been addressed. It is recommended to perform a test drive to ensure that the fault does not reoccur.
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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