blueandwhite

My 2007 Mercedes C230 was due for an emission test, so I take it to a test facility but their machine is unable to connect to the car via the OBD port as it keeps giving a "no communication error". We tried several different facilities but to no avail - they all result in the same no communication error. I tried several different OBDII scanners to see if they could connect, but they also similarly provide a communication error after attempting to scan the car. Now to confirm:

- the OBDII port receives power and has no broken pins; and
- the car was able to pass the OBDII emission test two years ago, and between then and now the car has not been modified nor have we experienced any issues.

I took the car to Mercedes who were equally as confused as I was, and they surprisingly concluded they could not diagnose the issue .

I went to a Merecedes indy shop who was able to connect to the car via Mercedes' STAR tool, albeit they mentioned it did take an unusually long time to connect and they had to manually enter the vehicle's VIN. After confirming the car was able to connect, we go to yet another drive clean facility who unfortunately still received a "no communication" error.

So I'm back to ground zero. Has anyone experienced such an issue, and if so, how did you solve it? I did some research and it seems people only experienced this if their OBD port was damaged or not receiving power, both of which are confirmed not to be the issues in my case.