P125B BMW Possible Causes
- Faulty nitrogen oxide (NOx) sensor
- Nitrogen oxide (NOx) sensor wiring harness is open or short-circuited
- Poor electrical connection in the nitrogen oxide (NOx) sensor circuit
How is BMW P125B 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 engine maintenance warning light)
P125B BMW Meaning
The engine control module (ECM) monitors the nitrogen oxide (NOx) sensor. The ECM sets the OBDII code when the nitrogen oxide (NOx) sensor does not meet factory specifications.