“AdBlue (DEF)” warning light on the dashboard: meaning and what to do

What you can do yourself

Top up AdBlue: the fault often clears after topping up and driving.
Level is fine but the fault stays — the system needs a diagnosis.

Stop and don’t drive on if:

The Check Engine light is flashing
The temperature gauge is in the red or the overheating light is on
The red oil pressure light is on
Smoke from under the bonnet, a burning or petrol smell
Strong jerking, knocking from the engine, or the car barely moves

The description comes from the AvtoElektrik PRO app.

Oleg’s tip: the colour of the symbol tells you how urgent it is

Red — stop and deal with the problem urgently: driving on is dangerous.
Yellow — needs checking to see what it is: don’t put off the diagnosis.
Green and blue — a system is simply working.
Exception — symbols of extra functions you switched on yourself: the rear fog light, ESP OFF by the button, heating, the differential lock. They can be yellow, but that’s not a fault — ignore them.

For example: a red oil pressure or overheating light — stop straight away and switch the engine off. A yellow Check Engine light with the engine running smoothly — drive on and get a diagnosis.

Need a mechanic’s help?

Couldn’t fix it yourself? Oleg, an auto electrician, does computer diagnostics and repairs: he comes out anywhere in Almaty or sees you at his workshop.

Car computer diagnostics in Almaty Call: +7 701 121 11 10

Want to figure it out yourself?

Oleg’s free course “Car electrics for drivers”: fuses, the battery, dashboard lights — understand it and check it yourself.

Car electrics for drivers course →

Error codes that come with this light

A scanner shows the exact cause. Tap a code to see its meaning, causes and what to check yourself.

Other lights of this colour

Who keeps this reference

The reference is kept by Oleg Dmitriev, an auto electrician from Almaty with 26 years of experience: computer diagnostics of cars and trucks, repair of control units (ECUs). Can’t find the cause? Message him.

Oleg’s auto electrician website WhatsApp +7 701 121 11 10

The “AdBlue (DEF)” light on the dashboard