platt-deutsch

Rotated the tires and now the tire pressures are in wrong location. Is there a way to relearn what tires are where?

Diesel Benz

Of course, read your car manual and it explains how to reset the TPMS system from the cluster menu after tyre rotation, change of tyre pressures etc. You will have to drive some time after the reset.

Edit: 221 should use Siemens sensors, learning is different from older Beru sensors, the car might even learn new sensor after a ride but still better to reset the system from the cluster menu.

famous550

It's on the screen. Read the manual to the car

platt-deutsch

I read the manual.. I reset it as described and it still reads the wrong tire positions. All the reset procedure seemed to do was establish new normal pressures without the warning.

famous550

You should take a trip to the dealer to have this checked out.

Diesel Benz

Did you have a good ride with the car after the reset? If it still did not recognise the change of sensors, perhaps it is best to let the dealer look at the car.

platt-deutsch

OK.. thanks guys.. will see what it does this week and will report what it does..

Em Bee Lover

Somewhat related. I am considering buying an additional set of wheels, so I can use the current 18" to put snows on. Swapping sensors twice a year would be nutso. I have 2007, 117125 off the line.

How do I know what the frequency is for my car, if I look at options besides paying $180 each for new ones from a dealer? I see 433 Mhz; I have seen 315 Mhz. I am not getting wheels through the dlr. I respect you DB, but why must only Siemens be used? Thanks.

Diesel Benz

Tire Rack is the sponsor of this forum and should be a good place to buy tyre pressure sensors in the US.
https://mbworld.org/forums/wheels-ti...-tire-rack-36/

They would certainly know which sensors fit your car.

Usually there is only one supplier for a specific MY, it used to be Beru like for early W211 cars and Siemens for later models and early 221 models. I'm actually not sure which company supplies sensors for current MB models.

Previously tyre pressure sensors were 315 MHz for the US cars and 433 MHz for European cars but some time ago US started accepting 433 MHz sensors and I believe models like the W212 have only one frequency option irrespectively of the market area.

A 2007 W221 however still has 433 MHz for European cars and 315 for US cars. The current MB part number should be A0025407917.

brownbomber

DB, that is a good question. Do you know specifically if the 433mhz sensors will work on a 315mhz 2007 US w221?

For whatever reason, the 433mhz sensors are so much cheaper and easier to find.

And lastly, do they have to have all the same frequency, i.e. (2) 433mhz, and (2) 315mhz...etc.

Diesel Benz

As far as I know, you cannot mix 433 MHz sensors with 315 MHz. If I remember right, also the car control unit is specific to the sensor operating frequency. Theoretically the control unit could be built to support both frequencies and the wheel sensors would be installed according to what is allowed for the specific market area. I should check this from EPC.