Short of a faulty connector or connection all OBD II scanners work the same. Note there are two scanner connections. One under the left side of the dash which is OBD and one under the hood which is MB proprietary.
All you need is an inexpensive OBD scanner (<$50) online. I've found the auto parts chain stores tend to have very over-priced scanners.
Some thing like this is fine -
AUTEL MaxiScan MS309 Code Scanner Reader CAN OBDII OBD2 EOBD : Amazon.com : Automotive