P229F

NOx Sensor Circuit Range/Performance Bank 2

P229F is a generic OBD-II powertrain diagnostic trouble code: NOx Sensor Circuit Range/Performance Bank 2. It is logged by the engine control unit when the scr/adblue monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P229F
Group
Powertrain
System
SCR/AdBlue
Severity
Warning (MIL on, possible limp mode)
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What P229F means

P229F is an SAE generic powertrain code that sets when the Engine Control Module (ECM) or Selective Catalytic Reduction (SCR) control module detects that the signal from the Bank 2 NOx sensor is outside the expected operating range, or that the sensor's performance does not correlate with calculated exhaust NOx levels. Unlike circuit-open or short codes, a Range/Performance fault means the sensor is electrically present but is delivering readings that are implausible given current engine load, exhaust temperature, and AdBlue dosing state.

The NOx sensor on Bank 2 is typically the downstream (post-SCR catalyst) sensor used to verify AdBlue conversion efficiency. When its output drifts, sticks, or responds too slowly to commanded changes in reductant dosing, the ECM logs P229F.

Common platforms affected include diesel passenger cars and light-duty trucks from VAG, BMW, Mercedes-Benz, Ford, GM Duramax, Ram/Cummins, and Nissan equipped with two-bank exhaust or dual NOx sensor configurations.

Common causes

Most-frequently reported root causes when P229F is logged.

  • 1
    Failed or contaminated Bank 2 NOx sensor (internal cell degradation or silicone/sulphur poisoning)
  • 2
    Faulty NOx sensor control unit / integrated heater circuit causing slow warm-up and sluggish response
  • 3
    Wiring harness damage, chafing, or corroded connector pins on the Bank 2 NOx sensor circuit
  • 4
    Inadequate AdBlue (DEF) quality or concentration causing abnormal exhaust chemistry
  • 5
    SCR catalyst degradation on Bank 2 producing NOx conversion readings outside calibrated correlation
  • 6
    Exhaust leaks upstream of the Bank 2 NOx sensor diluting the exhaust sample
  • 7
    ECM/SCR module software fault or calibration mismatch requiring a software update

Symptoms drivers notice

MIL (check engine light) illuminated
Possible AdBlue/DEF warning lamp or SCR system warning message
Reduced engine power or torque (limp mode) on vehicles that enforce SCR compliance
Increased tailpipe NOx emissions, potentially causing emissions test failure
Possible higher-than-normal AdBlue consumption
DTC co-occurrence with SCR efficiency codes (P20EE, P204F)

How to diagnose P229F

A typical diagnostic flow when this code is present.

  1. 1
    Retrieve all stored DTCs and freeze-frame data
  2. 2
    Inspect the Bank 2 NOx sensor connector and harness for corrosion, spread terminals, chafing
  3. 3
    Check AdBlue quality and concentration
  4. 4
    With a scan tool, compare the Bank 2 sensor output against Bank 1
  5. 5
    Inspect the exhaust system upstream of the Bank 2 NOx sensor for cracks
  6. 6
    Check for available ECM or SCR control module software updates
  7. 7
    Replace the Bank 2 NOx sensor if electrical checks and exhaust integrity are confirmed good

Vehicles where we've handled P229F

Platforms in our catalogue with confirmed P229F coverage.

VW TRANSPORTER
BMW 530XD
2017
BMW X5
2018–2019
AUDI A4 20D
BMW 320D
2016
AUDI A6
2015
AUDI A6 30D
2015
AUDI A7

Related powertrain codes

Frequently asked questions

Can I drive with a P229F code active?

Short-term driving is possible, but the MIL will remain on and emissions compliance is compromised. On vehicles with SCR enforcement logic, continued driving may trigger progressive power restriction.

Will clearing the code fix the problem?

No. Clearing the DTC only extinguishes the MIL temporarily. The ECM will re-set P229F within one to two drive cycles if the underlying fault persists.

Is P229F the same as P229E or P22A0?

They are closely related but distinct. P229E indicates the Bank 2 NOx sensor signal is too high. P229F indicates the signal is out of range or not correlating. P22A0 is a low-signal fault on Bank 1 Sensor 2.

How much does it cost to fix P229F?

If the NOx sensor itself has failed, replacement sensors typically cost between €150 and €600 depending on the vehicle platform.

Disabling P229F in software

RaceTune can permanently disable P229F — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

ECUs with a P229F disable in our catalogue

Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.

  • Bosch EDC17C74 verified 2 software versions
  • Bosch EDC17CP57 verified 2 software versions
  • Bosch EDC17C50 verified 1 software version
  • Bosch EDC17C56 verified 1 software version
  • Bosch EDC17C66 verified 1 software version
  • Bosch EDC17CP44 verified 1 software version
  • Bosch MD1CP002 verified 1 software version
  • Bosch MD1CP004 verified 1 software version

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

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