Beep from dash...DEF?

[Glamper1]

Does it mean low DEF?

[Ron_CA]

Your display will tell you if you need DEF. Check for messages.

[73shark]

Should get ~10K miles from a full DEF tank. Holds five gallons and can be found at Sam's Club and Walmart for about $11 for 2.5 gallons.

[Boxster1971]

What kind of beep? Only once or constant?


- - Mike
2013 Lounge EXT on 2012 Sprinter

[Boxster1971]

Also look in your owners manual under the indexed item "Warning Tones". Mine lists about five items that will give a warning tone. Any major vehicle issue will also give a warning message and possibly a CEL (Check Engine Light). Starting without hooking up the drivers seatbelt will give one initial warning tone and then start repeating every few minutes with the seat belt warning light on. Opening the drivers door with light turned on will also give a constant repeating warning tone. That should also gives a warning message.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[Protagonist]

Every time a new message pops up on the dashboard display, there will be a beep to draw your attention to it. Could be any message, from "door open" to "Schedule A service due now" to "Low fuel" to "Add DEF." You can make the message go away or come back by cycling through the displays using the buttons on the left side of the steering wheel. But there won't be anymore beeps until a new message pops up.

[Tiato]

Just a single beep? Or continuous?

[Msmoto]

Having owned a large (41,000 lbs.) moho which used DEF, I can say there are many issues which can occur. The sensors can fail in the tank and say you have none when it is full. They can trigger other warning lights to come on. The system can be cheated, at least in the early days, simply adding water in an emergency would allow operation for a few miles to get you to a supply of DEF. My DEF engine a Cummins 8.9 l, ISL ran beautifully, had huge power, over 1250 ft lbs of torque, 450 hp, and got about 9 mpg when no wind was present. SO DEF is good, but adds some complications.

Suget this is a dealer issue, if there is something wrong only a dealer with the proper diagnostics can figure it our, IMO

[Glamper1]

Hi and thank you.
The beep was continous then after turning engine off, it stopped.
Cqme back tgen stopped again.
No warning message.
I think it maybe a malfunctioning seatbelt warning sign but not certain.
I only have abour 1,700 mikes on engine.
I will buy some DEF just in case.
Thanks again

[Tiato]

Ok. As others have said if the Mercedes part doesn't show any messages after the beep, chances are it's not the chassis but something AS added.

Extend your awning a bit then retract again. In my experience if the awning is 99% retracted it gives the appearance of being fully retracted but then when going over a bumpy road loosens it a tiny bit further and enough to trip the sensor.

[73shark]

And you'll definitely get a DEF message when it starts to get low. Since it has a shelf life, I wouldn't get it too soon unless you're planning on some long trip.