NOx Sensor Circuit Range/Performance (Bank 1)
The DURAMAX-P2201 (Duramax) diesel fault code means: NOx Sensor Circuit Range/Performance (Bank 1). This is a serious severity code.
- Keep driving?
- Yes, with caution
- DIY difficulty
- advanced
Down with a Duramax fault on the road?
We are building a network of verified mobile diesel and reefer technicians along the freight corridor. It is not live yet — no one can be dispatched to you today. You can see where the pilot is launching and register interest.
View pilot availability →A $30 car code reader can't do diesel. The HD7000 reads full-system codes and does parked DPF regen, idle/speed-limit, and service resets from the cab — on everything from a 6.7 Cummins/Power Stroke/Duramax pickup to Class-8 trucks (Detroit, Paccar, CAT, Volvo, Mack, International).
Full-system 6/9/16-pin diesel scan tool for Cummins, Paccar, CAT, Detroit and more — plug-and-play, no subscription. A cheaper way to read heavy-duty codes a basic OBD2 scanner skips entirely.
Affiliate links — we earn a commission at no extra cost to you.
What Are the Symptoms of DURAMAX-P2201?
- Check Engine Light on
- Emissions or DEF system warning message
- Possible reduced power if the fault is not repaired
What Causes DURAMAX-P2201? (Most Likely First)
- Failed NOx sensor High
- Damaged wiring or a corroded connector near the exhaust High
- Sensor power or ground problem Moderate
- Exhaust leak near the sensor Low
Can I Still Drive with DURAMAX-P2201?
Yes, with caution. DURAMAX-P2201 is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
What does P2201 mean on a Duramax?
P2201 means NOx Sensor Circuit Range/Performance (Bank 1). The bank 1 NOx sensor is reporting, but its reading does not make sense for the operating conditions.
Is P2201 a Duramax-specific code?
No. P2201 is a generic OBD-II code defined by SAE J2012, so it means the same thing on any vehicle that sets it. The exact conditions GM uses to set it on its diesels are in GM service information.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose DURAMAX-P2201?
Find which NOx sensor is bank 1 on your truck in the service information.
Inspect the sensor connector and harness for heat damage.
Check the sensor power and ground before replacing it.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines P2201 as a generic OBD-II code)
P2201 on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:
Explore More
Was this helpful?
Send this to whoever is fixing the truck — your tech, or the person asking what the fault means.