P127B BMW Possible Causes
- Faulty nitrogen oxide sensor (NOx)
- Nitrogen oxide sensor (NOx) harness is open or shorted
- Poor electrical connection in the nitrogen oxide sensor (NOx) circuit
How is BMW P127B Code Repair Done?
Start by checking the “Possible Causes” listed above. Visually inspect the wiring harness and related 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)
P127B BMW Meaning
The Engine Control Module (ECM) monitors the nitrogen oxide sensor (NOx). The ECM sets the OBDII code when the nitrogen oxide sensor (NOx) does not meet factory specifications.