P123C BMW Possible Causes
- Faulty nitrogen oxide (NOx) sensor signal Binary oxygen sensor
- Nitrogen oxide (NOx) sensor signal Binary oxygen sensor wiring harness open or short circuit
- Nitrogen oxide (NOx) sensor signal Binary oxygen sensor circuit poor electrical connection
How is BMW P123C 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)
P123C 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.