Amber · Investigate soon
AdBlue warning light — what it means
AdBlue (SCR) lights warn that urea level is low or the dosing system has a fault. Modern diesels can countdown to a no-restart condition — which is exactly why people Google this at the services.
Also called: AdBlue, urea, SCR
What it means
AdBlue level low or SCR system fault. Cars can refuse to restart when empty.
What to do first: Refill with proper AdBlue soon. Persistent light after fill = diagnostics.
Common causes
- Low AdBlue level
- Crystalised deposits / contaminated fluid
- Failed level quality sensor or injector
- Software faults after a poor refill
Step-by-step
- 1Refill with sealed ISO 22241 AdBlue — never into the diesel filler.
- 2Add enough fluid; tiny top-ups may not clear the warning.
- 3If the light remains after a confirmed fill, book diagnostics before the restart lockout.
- 4Do not delete the SCR system for road use.
MOT note
Emissions and MIL-related AdBlue faults can fail MOT; deleted systems are illegal.
FAQs
- How many miles can I drive with AdBlue light on?
- Follow the message countdown on your dash — it varies by car. Do not plan to empty the tank completely.
Related
Other warning lights
Icons from Wikimedia Commons dashboard tell-tales / ISO 7000. Manufacturer artwork varies — your handbook wins.