P2200 is the general electrical fault reported for the front NOx sensor on bank 1, the unit ahead of the SCR catalyst. Such sensors carry their own control unit, which checks the probe wiring and reports the result over CAN. GM's 6.6L Duramax (LML) sets P2200 as a Type A fault once an open-circuit status keeps arriving for more than 0.5 s or 10 s, depending on calibration. Ford's 6.7L and 3.0L diesels use it for shorts or opens on the probe lines and for memory checksum errors inside the sensor controller. VW's 2014 Touareg TDI reacts to an error message or a validity ratio of at least 0.5. P2201 covers plausibility, P2202/P2203 a value out of range, P229E the downstream sensor. Dosing loses its feedback and the MIL comes on.
Medium severity. Can I keep driving?You can usually keep driving in the short term, but get it repaired soon: on many diesels, the warning eventually limits starting or engine power.
Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.
Symptoms
- Malfunction indicator lamp on
- No NOx value in live data from the upstream sensor
- SCR or emissions warning, possibly followed by inducement countdown
Most likely causes
- Internal fault in the NOx probe or its attached control unit
- Damaged cable between probe and sensor control unit (heat, chafing)
- Moisture or corrosion in the sensor connector
- Unstable supply or ground at the sensor control unit
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P2200 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 2: Fuel injection
- 00: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2200?
You can usually keep driving in the short term, but get it repaired soon: on many diesels, the warning eventually limits starting or engine power.
What causes code P2200?
The most common causes are: internal fault in the NOx probe or its attached control unit; damaged cable between probe and sensor control unit (heat, chafing); moisture or corrosion in the sensor connector.
Related codes
- P2201NOx Sensor Circuit Range/Performance (Bank 1 Sensor 1)
- P2202NOx Sensor Circuit Low (Bank 1 Sensor 1)
- P2203NOx Sensor Circuit High (Bank 1 Sensor 1)
- P2204NOx Sensor Circuit Intermittent (Bank 1 Sensor 1)
- P220ANOx Sensor Supply Voltage Circuit (Bank 1 Sensor 1)
- P229ENOx Sensor Circuit (Bank 1 Sensor 2)
- P2213NOx Sensor Circuit (Bank 2)
- U029DLost Communication With NOx Sensor A
Sources
- gsi.ext.gm.com: 14OBDG10 Engine Diagnostics
- fordservicecontent.com: obd summary diesel 2023
- static.nhtsa.gov: MC 10074008 2280
- static.nhtsa.gov: MC 10201707 0001
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.