Amber — check soon
AdBlue (urea)
The AdBlue fluid is running out — a diesel needs it to neutralise nitrogen oxides. The car usually shows the remaining range as well.
An amber lamp means you can drive on, but do not put it off. The car runs in a protective mode and usually drinks more.
What to do now
- Top the fluid up. It is sold at filling stations, goes into its own filler and is inexpensive.
- ⚠️ Do not leave it to zero: on many cars an empty tank means the engine WILL NOT START next time — that is required by law, not a fault.
- Use only genuine fluid to the proper standard. Water or a diluted solution ruin an expensive sensor and the catalyst.
- If the lamp is on with a full tank, read the codes: usually the level sensor or a crystallised injector is to blame rather than the catalyst.
Codes usually behind it
The lamp only says that something is wrong. The code says what exactly — read it with an adapter and look it up here.
P203BReductant level sensor — malfunctionP2047Reductant injector — circuit malfunctionP2048Reductant injector — low signalP204FReductant system performance below limitP20EESCR catalyst efficiency below limit (bank 1)
What to read next
A lamp is not a diagnosis. The same symbol lights up for a dozen different reasons, and only the code stored in the car tells them apart.
How the app helps
CarScan reads the codes behind the lamp through an OBD-II adapter, explains them in plain words and puts them into a report you can show to a mechanic.