P123E BMW Possible Causes
- Faulty nitrogen oxide (NOx) sensor
- Nitrogen oxide (NOx) sensor harness is open or shorted
- Poor electrical connection in the nitrogen oxide (NOx) circuit
How is BMW P123E Code Repair Performed?
Start by checking the “Possible Causes” listed above. Visually inspect the wiring harness and associated connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
- Engine light on (or service engine soon warning light)
P123E BMW Meaning
The Engine Control Module (ECM) monitors the nitrogen oxide sensor. The ECM sets the OBDII code when the nitrogen oxide sensor does not meet factory specifications.