P2201 — NOx Sensor Circuit Range Bank 1
Seen on: Heavy Truck/Diesel
NOx Sensor Circuit Range Bank 1. Common causes: NOx sensor out-of-range reading.
Look up listed providers near you and give them this code when you call.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- NOx sensor out-of-range reading
- Contamination
- aging sensor
First moves (roadside)
- Compare upstream vs downstream NOx
- replace if upstream reads erratic
FAQ
NOx Sensor Circuit Range Bank 1. Common causes: NOx sensor out-of-range reading.
Serious — Power derate likely — plan to stop soon.
The most common cause is: NOx sensor out-of-range reading. Other possibilities include Contamination; aging sensor.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Find a mechanic or related guides
General diagnostic guidance for diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.