To function properly, BlueTEC exhaust gas aftertreatment must be operated with the reducing agent DEF.

When the DEF supply has almost run out, the Check Additive See Operator's Manual message is shown in the multifunction display.

When the DEF supply sinks to a minimum level, the Remaining Starts: 16 message is shown in the multifunction display.

When the Remaining Starts: 16 message is shown in the multifunction display, you can start the engine 16 more times. If DEF is not added, it will not be possible to restart the engine. Fill the DEF tank with approx. 1 gal (3.8 l) DEF, or have it filled at a qualified specialist workshop.

If you drive the vehicle faster than 10 mph (16 km/h), the Check Additive See Operator's Manual message goes off after approximately one minute.

Further information about BlueTEC exhaust gas aftertreatment and DEF is available at any authorized Mercedes-Benz Center.