BMW P128B code possible causes
- Faulty nitrogen oxide (NOx) sensor
- Nitrogen oxide (NOx) sensor harness is open or short-circuited
- Poor electrical connection in the nitrogen oxide (NOx) sensor circuit
How is BMW P128B 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.
What are the possible symptoms of BMW P128B code?
- Check engine light on (or Service Engine Soon warning light)
What does BMW P128B code mean?
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.