2013 M B sprinter 3500 D E F and check engine light on will no t erase D E F topted off but light remains on
Are you certain the check engine light is on because the computer detects a diesel exhaust fluid problem? I suspect there is an unrelated fault detected. Post the fault code stored in the computer.
When the check-engine light is on, the first step is to have the stored codes read. In most states, auto parts stores will do this for free.