P229F: NOx Sensor Circuit Range/Performance (Bank 1 Sensor 2)
14 vehicles · 8 makes · $150-$3,500 repair
Most Reported On
P229F is an OBD-II diagnostic trouble code meaning “NOx Sensor Circuit Range/Performance (Bank 1 Sensor 2).” P229F indicates the engine control module detected a range/performance problem with the downstream NOx sensor on bank 1 (sensor 2), most common on diesel vehicles with SCR/AdBlue emissions systems. The NOx sensor measures nitrogen-oxide levels in the exhaust so the system can dose diesel exhaust fluid correctly and verify the catalyst is working. An implausible or out-of-range signal can trigger emissions warnings, reduced power, and on many diesels eventual no-start countdowns tied to emissions compliance. It is an emissions-system fault that should be addressed before it escalates. This code is most commonly reported on 2014-2025 Mercedes-Benz Sprinter (Sprinter 1500, Sprinter 2500, Sprinter 3500, Sprinter 4500), 2018-2023 Ford Transit, and 2017-2023 Skoda Kodiaq, plus 11 other vehicles, with repair costs ranging from $150 to $3,500.
Common Causes
Typical Repair Cost
Based on 14 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
This is a powertrain code, so a basic OBD-II reader can read it. These read P229F.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.
- Read & clear engine (P) codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X V3.0 Elite OBD-II Scanner
by LAUNCH
Handheld scanner covering the four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
What you can do yourself, and what needs a shop
Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:
- Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
- Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
- Airbag/SRS component work — a stored fault can deploy a live device.
If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.
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Vehicles Affected (14)
DEF/AdBlue SCR System Faults and Derate
Diesel EGR/DPF Clogging & AdBlue (SCR) System Faults (OM651/OM654)
AdBlue/SCR System Faults Triggering Limp Mode and No-Start Countdown
NOx Sensor Failure in the SCR/AdBlue System Triggering a Start-Prevention Countdown
Diesel AdBlue / SCR NOx Sensor Fault Triggering Restart Countdown and No-Start
NOx Sensor / SCR System Failure on Euro 6 Diesels (Zafira Tourer C)
Diesel AdBlue / SCR system failure preventing engine restart
Diesel SCR/AdBlue & NOx Sensor Emissions Fault with 'Starting Impossible' Limp Mode
FAQ
What does P229F mean?
P229F stands for "NOx Sensor Circuit Range/Performance (Bank 1 Sensor 2)." P229F indicates the engine control module detected a range/performance problem with the downstream NOx sensor on bank 1 (sensor 2), most common on diesel vehicles with SCR/AdBlue emissions systems. The NOx sensor measures nitrogen-oxide levels in the exhaust so the system can dose diesel exhaust fluid correctly and verify the catalyst is working. An implausible or out-of-range signal can trigger emissions warnings, reduced power, and on many diesels eventual no-start countdowns tied to emissions compliance. It is an emissions-system fault that should be addressed before it escalates.
What are the most common causes of P229F?
The most common causes of P229F are: Faulty downstream NOx sensor (bank 1 sensor 2), Wiring or connector corrosion at the NOx sensor, Exhaust leak upstream of the sensor, Contaminated or incorrect diesel exhaust fluid (DEF/AdBlue), SCR catalyst degradation, NOx sensor control-module communication fault, ECM software needing update/recalibration. The specific cause varies by vehicle.
How much does it cost to fix P229F?
Repair costs for P229F range from $150 to $3,500, depending on the vehicle and root cause.
Which vehicles are affected by P229F?
Au7o has documented P229F across 14 vehicle models from 8 manufacturers: Chevrolet, Dacia, Ford, Genesis, Mercedes-Benz, Opel, Skoda, Volkswagen.
Sources (12)
- NHTSANHTSA Manufacturer Communications Data Corpus
- ForumAdblue system fault | Skoda Kodiaq SUV Forum
- ForumSkoda Kodiaq 2.0 TDI problems with DPF regeneration | MyCarly Community
- articleDPF warning light ON in Skoda Kodiaq. What to check? | DailyDriven
- articleNOX Sensor Fehler am Opel Zafira C Tourer nach 80000km — MOTOR-TALK
- articleNOx Sensor — Opel Zafira Tourer C 2.0 CDTi B20DTH (Motordoctor)
- articleMercedes OM651 & OM654 AdBlue Faults | SCR Fix - Precision Remaps UK
- articleMercedes OM651 diesel engine: common problems, reliability
- articleMercedes AdBlue Delete - Fix No-Start & Countdown Issues (Stoke Tuning)
- ForumW447 V-Class AdBlue Countdown Reset - autogmt.com
- articleMercedes Benz P229F62 and P2202 error codes explained - Xenons4U
- ForumReplace NOx sensor or delete AdBlue? - MBWorld.org Forums
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.