check compartment where battery is housed to see if water is present in the area under battery. ask dealer to make sure vehicle has latest software patches installed if batery compartment is dry..if its wet ... well i would petition MBUSA for a goodwill warranty repair as some early R, GL and ML vehicles had evaporator drains not installed properly causing various problems with modules located in electrical 'tub ' below front seats. Even then module replacement must include careful inspection of wiring connectors as just simple ecu replacemnt would only provide short term operation before corrosion at the terminals caused trouble again