AdBlue / SCR system warning light: meaning and what to do

AdBlue / SCR system

The exact symbol can vary between makes and models. Also check the message displayed by the vehicle.

How urgent is it?

Act before the displayed range expires; an SCR fault needs diagnosis.

How to recognise it

AdBlue text or reagent/exhaust symbol.

What it can mean

It can mean low reagent level or an SCR fault. A countdown message can warn that restarting will be prevented.

What to do

Follow the message and refill the correct tank according to the handbook. Never add AdBlue to diesel fuel. Arrange checks if the level is sufficient or the warning persists.

Before clearing the light or codes

Photograph the dashboard message and save all codes, the reporting module, fault status and freeze-frame data. Clearing can remove useful evidence without repairing the cause.

Useful terms

From warning light to inspection

A warning light can have many causes. The example codes below have NOT been scanned from your vehicle.