How much AdBlue does a Sprinter hold?

Roughly 22 litres on most modern Sprinters, but it varies by model and year - check your handbook for the exact figure.

How do I reset the AdBlue warning?

Top up correctly with fresh fluid and drive; a genuine low-level warning clears itself. If it persists, it is a system fault that needs diagnosis, not a reset.

Can I drive with the AdBlue light on?

Briefly - but if it is counting down "starts remaining", the van may refuse to restart once it reaches zero. Act before then.

Mercedes Sprinter AdBlue: Tank Location, Capacity & Topping Up Without Causing a Fault

On most Sprinters the AdBlue (DEF) filler wears a blue cap, usually sitting next to the diesel filler or hiding under the bonnet, and the tank holds roughly 22 litres - check your handbook for your exact model and year. Fill it with fresh, sealed AdBlue to the right spec (ISO 22241), add a proper glug rather than a nervous splash, then drive - the warning normally clears itself within a short run. If it stubbornly doesn't, you've got a system fault, not a fluid problem.

Where the tank and filler are

W907 (2018 on): usually a blue filler cap beside the diesel filler.
W906 (2006-2018): often under the bonnet or behind a separate flap.

Exact placement varies by year and build, so if in doubt, the handbook wins.

The one mistake that ruins your week: never put AdBlue in the diesel tank, or diesel in the AdBlue tank. Cross-contamination is an expensive, tow-truck sort of error - the blue cap is blue for a reason.

How to top up properly

1 Use fresh, sealed AdBlue to ISO 22241 - not an old open bottle from the back of the garage; it degrades.

2 Add a sensible amount (e.g. 10 litres), not a tiny splash, so the sensor actually registers the change.

3 Avoid spills on paint and connectors, and keep dirt out of the tank.

4 Turn the ignition on and drive - the countdown or warning should clear within a short run.

When topping up won't clear the warning

If the light digs its heels in, or you're now reading "AdBlue system fault" or "X starts remaining", the problem usually isn't low fluid at all - it's a NOx sensor, an SCR/metering fault, crystallisation, or a sulky quality sensor. Clearing the code won't fix it (here's why clearing the AdBlue countdown isn't a fix), and on a Vito it's the same song, different verse - see the Vito AdBlue fault guide.

Don't ignore the countdown

If the dash is counting down "starts remaining", that's a hard deadline. Run it to zero and the van may simply refuse to restart - sort it before then, not after.

Disabling the SCR/AdBlue system ("AdBlue delete") is illegal on a road van and an MOT failure - so we diagnose and repair it rather than take the cowboy exit. Book a mobile AdBlue/SCR diagnostic across Kent and SE London.

Mercedes Sprinter AdBlue: Tank Location, Capacity & Topping Up Without Causing a Fault

Where the tank and filler are

How to top up properly

When topping up won't clear the warning

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