P2200 NOx sensor circuit (bank 1)
P2200 tends to reappear because the ECU checks the NOx sensor circuit every time the engine runs, and a wiring or sensor fault doesn't heal itself. We test the sensor and its wiring at your home, yard or depot so you know what to replace.
Why P2200 comes back after clearing
Clearing the code resets the light, but the ECU starts monitoring the NOx sensor circuit again from the next start-up. If the signal is missing or the sensor's own module reports an internal fault, P2200 is logged within a journey or two.
The official wording, NOx sensor circuit (bank 1), covers the whole circuit, so the fault could be the sensor, its control module or the wiring between them and the ECU. Until that's narrowed down, clearing it only buys a few quiet days.
The usual causes behind P2200
| Cause | How it's checked |
|---|---|
| Failed NOx sensor element or heater | Sensor status and readings on live data, compared with a warm engine |
| Fault in the module attached to the sensor | Module communication and its own fault memory |
| Chafed, melted or corroded wiring near the exhaust | Visual check and circuit tests along the loom |
| Water in the connector | Connector inspection and resistance checks |
| Power or earth supply problem to the sensor | Supply voltage and earth checks |
Symptoms
- The engine management light back soon after it's cleared
- An AdBlue or emissions warning on the dash
- A no-restart countdown on many Euro 6 vehicles
- Little or no change in how the vehicle pulls
- Other NOx codes such as P2201 stored alongside
Using the vehicle with P2200 showing
Most vehicles feel normal, which is why P2200 gets left. Without a working NOx sensor, though, the SCR system can't check itself, and on many Euro 6 vans and cars that starts a countdown to a no-restart. Get it checked well before the counter runs low.
Vans and fleets with P2200
NOx sensors sit in a hot, wet spot under the vehicle, and van wiring takes plenty of punishment from road spray. We check vans at your yard or depot between jobs, so a countdown doesn't strand a van mid-week.
Fleet operators who use us regularly can set up a trade account through our trade and partners page.
How we stop P2200 coming back
NOx circuit diagnosis, £100 + VAT
We read the codes, sensor status and module data, then test the wiring and supply. You'll know whether it's the sensor, module or loom before anything is ordered.
Sensor or wiring repair
We don't repair AdBlue or SCR parts. A dealer or a garage that handles SCR systems can fit the sensor or repair the wiring, using our findings.
AdBlue delete, £330 + VAT
A software delete removes the SCR monitoring the sensor reports to, so a failed NOx sensor no longer sets the code.
Reviews
Why does P2200 come back after it's been cleared?
The ECU watches the NOx sensor circuit constantly. If the sensor, module or wiring is still faulty, the next check fails and the code is stored again, often the same day.
Can a remap cause P2200?
A remap doesn't touch the NOx sensor circuit, so it's an unlikely cause. A well set-up map leaves the emissions monitoring alone, and P2200 points to a circuit or sensor fault.
Can another fault set off P2200?
A blown fuse or a poor earth shared with other parts can cut the sensor's supply. An exhaust leak near the sensor can also upset it, so related codes are worth reading together.
Can you check P2200 on our vans at the depot?
Yes. We'll come to the yard or depot, read each van and give you a list of which need a sensor and which need wiring work.
What should I tell you when I book for P2200?
The registration, the full code and any sub-code, any countdown figure and other warnings. If you're running a Mercedes or Peugeot, let us know the model, as sensor positions vary.
Which vehicles with P2200 can have an AdBlue delete?
Only those used off-road or going for export, as the delete isn't for vehicles on UK roads. Our guide Is AdBlue delete legal? sets out why.
Stop P2200 coming back
Book a fault check and we'll find out what's wrong with the NOx circuit, at home or at the depot.
More fault codes explained
Eccles, Manchester M30 0SF