OBD-II Diagnostic Trouble Code
P2200 — NOx Sensor Circuit Bank 1
P2200 indicates a general circuit fault with the bank 1 NOx sensor, which on most heavy diesels is the upstream (engine-out) NOx sensor ahead of the SCR. The sensor is a smart sensor with its own control module that reports over the CAN data link, so the ECM may be reporting lost communication or an internal sensor circuit fault; exact location varies by OEM.
Severity 4/5
Truck-relevant
Stop within 50 mi
Severity
Stop within 50 mi
NOx Sensor Circuit Bank 1
Code
P2200
Category
Powertrain
Subsystem
Aftertreatment
Truck-relevant
Yes
What this means for truckers
P2200 (NOx Sensor Circuit Bank 1) — generic version of the NOx sensor codes. See P20EE/P229F prevention notes.
Before you replace parts — try this first
P2200 on the Aftertreatment system is most often failed nox sensor or its control module — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
The check-engine or emissions light comes on and the SCR system may lose closed-loop DEF dosing control. Many trucks start a timed derate countdown (often to a low speed limit) if the fault is not repaired, though the engine usually drives normally at first.
Common causes
- CommonFailed NOx sensor or its control module ($450–$1200)
- CommonDamaged NOx sensor harness or connector from heat or chafing ($100–$400)
- OccasionalLoss of power, ground or CAN communication to the sensor module ($100–$450)
- RareECM or aftertreatment control module fault ($800–$2500)
How to fix
Check the NOx sensor module connector for power, ground and CAN high/low voltages
When to use: First, especially if the scan tool shows no data from the sensor
Inspect the sensor harness along the exhaust for melted or chafed sections
When to use: When power and CAN are intermittent
Replace the NOx sensor assembly (probe and module as one unit) and clear codes
When to use: When wiring and supply are verified good
Run an OEM SCR performance or NOx sensor verification test
When to use: After repair to confirm the fix and reset derate
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P229E — NOx Sensor Circuit Bank 1 Sensor 2
- → P229F — NOx Sensor Bank 1 Sensor 2
- → P22A4 — Reductant Heater B Control Circuit/Open
- → P22A5 — Reductant Heater B Control Circuit Low
- → P22A6 — Reductant Heater B Control Circuit High
Frequently Asked Questions
Can I drive with code P2200?
Drive with caution. P2200 is severity 4 — stop within ~50 miles. Most commercial diesel codes at this severity (turbo, fuel rail, transmission solenoid) can damage adjacent expensive components if left unrepaired. Get to a service location before highway-speed loads.
How much does it cost to fix P2200 on a commercial truck?
Total repair cost ranges $100–$2500 depending on the root cause. The cheapest fix is usually the first one listed below — Failed NOx sensor or its control module — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will P2200 fail a DOT inspection?
Yes — P2200 is an emissions-related code, and DOT inspectors check emissions compliance. An active emissions code with a check engine light can result in an out-of-service violation under FMCSA Part 393. The truck typically can't be moved until the code is cleared. Repeated emissions violations escalate to CSA scores.
What's the difference between P2200 and related codes?
P2200 is closely related to: P229E (NOx Sensor Circuit Bank 1 Sensor 2), P229F (NOx Sensor Bank 1 Sensor 2), P22A4 (Reductant Heater B Control Circuit/Open), P22A5 (Reductant Heater B Control Circuit Low). These codes share the same subsystem (aftertreatment) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only P2200 is set without the companions, the issue is more isolated.
How do I prevent P2200 from coming back after a repair?
For P2200 (NOx Sensor Circuit Bank 1), prevention centers on the aftertreatment system. Run quality DEF (verify supplier — BlueDEF, PEAK, Yara Air1). Don't skip parked regens — when the dash asks for one, do it. Avoid extended idle time which fouls the DPF. Replace NOx sensors at the OEM interval (typically 400K miles).