What does P2200 mean?
NOx sensors measure nitrogen oxides before and after the SCR catalyst. The computer uses them to dose DEF and to check that the SCR system is working.
The computer has detected an electrical fault in the sensor circuit.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Check engine light
- DEF/emissions warning message
- Possible speed limit countdown (derate)
Common causes
- Open or shorted wiring
- Corroded or loose connector
- Failed sensor
- Blown fuse or reference voltage issue shared with other sensors
How to diagnose P2200
- Look for other codes that share the same 5 V reference circuit.
- Inspect the connector and wiring, then check reference, ground and signal voltages.
- Replace the sensor only after the wiring tests good.
- Check for exhaust leaks.
- Look at NOx sensor readings with a capable scan tool.
How to fix it
- Replace the NOx sensor
- Repair wiring
- Repair exhaust leaks
Estimated repair cost
Likely repairs for P2200 run from about $400 to $1,000, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| NOx sensor replacement (one) | $400 - $1,000 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P2200?
High severity
Watch the dash. Many diesels start a speed-limit countdown for SCR faults, so get it in soon.
P2200 FAQ
What does P2200 mean?
P2200 stands for "NOx Sensor Circuit (Bank 1)". NOx sensors measure nitrogen oxides before and after the SCR catalyst.
Can I drive with a P2200 code?
Watch the dash. Many diesels start a speed-limit countdown for SCR faults, so get it in soon.
How much does it cost to fix P2200?
It depends on the cause. The likely repairs for P2200 range from about $400 to $1,000 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P2200?
The most common causes are: open or shorted wiring; corroded or loose connector; failed sensor.