SCR and AdBlue
NOx after-treatment: reductant dosing, NOx sensors, SCR catalyst efficiency. Distinct from the DPF even though both live in the exhaust.
15 documented codes across 65 real diagnostics.
Ranked by how often we actually see them
| Code | What it is | Diagnostics |
|---|---|---|
| P20EE | SCR NOx catalyst efficiency below threshold, bank 1 | 27 |
| P2BA9 | Not individually documented | 6 |
| P20E8 | Not individually documented | 5 |
| P2BAF | Not individually documented | 4 |
| P20F6 | Not individually documented | 3 |
| P204B | Not individually documented | 3 |
| P2BAE | Not individually documented | 3 |
| P229E | Not individually documented | 3 |
| P220A | Not individually documented | 2 |
| P229F | Not individually documented | 2 |
| P2049 | Not individually documented | 2 |
| P220E | Not individually documented | 2 |
| P2202 | NOx sensor circuit range/performance, bank 1 | 1 |
| P2203 | NOx sensor circuit high, bank 1 | 1 |
| P2043 | Reductant tank temperature sensor circuit | 1 |
FAQ
Frequently asked questions
How do I run a diagnosis?
Select the vehicle on Start, click the Diagnostic card and choose New diagnostic. Fill in the description, the error codes and the mileage, then click Analyze.
Learn more: Diagnostic (vehicle-first start), Diagnostic form: description, error codes and mileage
Do I have to type the codes from my scan tool?
No. Click the camera button next to Error codes and take or choose a photo (JPEG or PNG) of the scan tool's screen; WrenchLane reads the codes and their descriptions into the form. You can also speak them with the microphone.
Learn more: OBD reader photo scan (fault codes from a photo), Voice input for the problem description
Are the public fault code pages built from my diagnostics?
They are built from anonymised, aggregated diagnostics run in WrenchLane; no workshop, customer or vehicle can be identified. Each fault code page shows how often the code was seen across those diagnostics and in how many separate workshops.
Learn more: Fault code pages on wrenchlane.com (fault-code cluster)
Work a scr and adblue fault on a real car
Enter the codes and the symptoms and get ranked probable causes for that specific vehicle, with the checks in the order worth doing them. Free account, no card.
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