Bought a new set of tires for my 2014 ML. Even after driving over 100 miles, the pressure will not display. Took it back to the tire shop, connected a OBD port and it shows the system working. The display says “tire pressure active” but no numbers. Even after hitting “ok” and “set new pressure “ nothing displays.

Any idea how to reset the display?

 

it sounds like replacement procedure has not been completed or more likely uncompatible sensor units in use.
It should display within 5Miles... 100Mi okay!!

Connect your OBD MB scanner to confirm TPMS sensors read blank from TPMS Module registers.

 

The tire shop should have scanner capable activating each TPMS individually and reading its data. Ask if they can do this. They should be to tell you also if they're compatible with your vehicle. Where did you purchase the TPMSs?

 

The scanner shows each individual tire. We let air out and the scanner shows a drop. No sensors were changed. They simply do not show numbers.

 

How does the scanner show a drop without number ??
How old are your wheel sensors you said?

 

The instrument on the dash only shows “tire pressure active”, no numbers. It worked properly prior to the tire change. The sensors are not the problem, it is what is displayed on the dash.

 

The TPMS pressures were displayed until the tires were renewed.
Read TPMS data to visualize what sensors the module can receive.

 

Your earlier post indicated use of an OBD connected device. Your tire guy checked them with his hand-held scanner at each valve stem also, and all the TPMS's were functional(?). I don't understand why some of these systems take so long to recalibrate. I installed new tires and TPMSs on my Wrangler last week. When I drove away from the tires shop, 3 sensors were already working, and the fourth came online within a couple miles. But I've read about others who have driven more than 100 miles before they begin working.

 

Well after another few hundred miles, the display is working perfectly. I must have a self repairing W166.

Thank you to all of you that tried to diagnose it.

 

It is still odd that this happened since only the tires were replaced and not the sensors.

I have replaced my all-season tires before with absolutely no malfunction. That was done at the Mercedes dealer, however. But I also bought a set of winter tires and wheels as a set from TireRack with new TPMS sensors installed. They too worked perfectly.