Have you taken care of the prerequisites ?
Requirements for MHD
1. Checked your vehicle for: MEVD1726 DME (built dating from around 03-2012) need a once time DME removal and bench flash to allow OBD flashing.
This will stop you from going forward
2. Purchased the required hardware:
- 1 device running Android 3.2 and up, USB OTG compatible.
- 1 K+Dcan cable. See page 5 of the user manual for a recommended
- 1 USB OTG cable.
3. Installed:
- Flasher module: $199
- Monitor module: $69