I was told by a mechanic that a new tire pressure monitor sensor had to be coded by a dealership, otherwise it would not work. Is this correct?

System should recognize sensor after IC reset.

above bit from konigstiger is about the reference threshold

I don't believe they auto learn a different sensor BT code or you could pick up another guy's in traffic
just about any Tyre shop should have kit to write the code - they have been on cars for 18 years - and many you code the sensor to match the car as its a simpler better method

I was hoping this would be about the difference between the displayed amount and what a real gauge says. I adjusted my tire pressure after a cold snap, pumped everything to 38, and the dash said 35-36.

I looked up the tire sensors on rockauto and they sell a kit of sensors and a device to apparently code the sensors which leads me to believe that the car does not automatically recognize them.

I had Belle Tire install a new one and it worked fine. Not sure what they did as far as programming.

I have second sets of wheels with Winter tires and have no problems with TPMS when I switch over.

Does this mean the system can remember 8 wheels sensors? I don't know.

Of course I do the reset and off I go, no problems.

I replaced a set of rims with another set with new tire pressure monitors, no coding involved.

but what sensors did u use?

if you have 8 independent Mercedes OEM Bluetooth sensors and the car just copes I'd be surprised - but if you used aftermarket sensors and just cloned the four you have and put these on or the original wheels of course the car won't care / have any way to know any better

this is the posher spec setup "highline" option 475

All you need to do is purchase sensors that operate at 315Mhz.

Seems two different topics get mixed here. OEM Mercedes tyre pressure sensors have been coded to work in the car. The car just needs to run the sensor address identification process if sensors have been changed. The cluster reset the konigstiger referred to, does this in addition to setting the current tyre pressure as the watched after figures.

Older MB cars need this reset, later models can identify new sensors automatically but I would use the cluster reset menu anyway.

The other thing is generic sensors from tyre shops. The tyre shop needs to code these sensor to follow the MB sensor data protocol. That is to make them work the way OEM sensors for Mercedes would.

It is also possible to teach in sensor addresses with the diagnosis tool but this is not mandatory. Just makes the system work instantly. Autonomous learning may take tens of kilometres, depending on the driven road.

I come from a country where we use a different set of tyres for the winter from those for the summer. I do not need diagnosis tools or assistance from a tyre shop when I change from winter to summer tyres or vice versa. My current tyre set on the W223 actually has non-OEM sensors. The tyre shop did code the sensors to follow the W223 MB protocol. The tyre shop never saw my car, the sensors (sensor addresses) were not coded to my car. The car still did figured out the new sensors after some 20 km ride. After reset the cluster says that the sensor only start to work after some driving.

Have to be careful out there. Mercedes has used many different sensors over years, not compatible with different body styles (MY) even if working on the same frequency band. The 211 sensors do not work on a 221, the 221 sensors do not work on a 223 or a 213 facelift etc. etc.

I should have said any 315Mhz sensor advertised to work with your year and model.

I bought mine on Amazon. They work.

Europe 221's don't use 315mhz, mine are 433mhz - some strange BT rules and regs differences on the phone systems too

there a story about hz, its the wrong name, he waited till the guy went on holiday and published someone else's work, bit like marconi who never invented the radio and had to pay for patents to pretend he had... both crooks stole the work off the very same guy who also made the device that sets fire to your petrol each drive

Wow, you're running some pressure! Except for the leaker. I run 40 up front and 30 in back. They're staggered fitment and I have a very heavy foot. This keeps things wearing flat. My last set of tires wore out both edges in the front and the centers in the back. I used the recommended air pressure on the door jamb. It didn't work out for me.

that one is not my car (but same system in mine - except I'm on bar and degrees C )

30 PSI is dangerously low - I pushed a post the other day about tyre pressures and ride comfort... Usual run 2.6 bar (14.7 psi per bar), but being lazy it was dropping and with time and got to 1.9 and I decided to trade off wear for ride comfort - but ride comfort was still awful. However I did notice mpg was falling off a cliff and eventually realised the link (doh), so decided to try a bit more and have ended up at 3.1 bar all round and the car drives much the same - ride comfort hasn't changed at all ???

the book says

Unladen Tyre pressure setting for a Mercedes S Class with the size of 255/45R18 and Manufactured between the years of 09 - 14:

Front recommended unladen / unloaded tyre pressure in pounds per square inch is 35 PSI or 2.4 BAR or 39 PSI with a load (19 and 20" higher with 44 PSI loaded)

Rear recommended unladen / unloaded tyre pressure in pounds per square inch is 38 PSI or 2.6 BAR or 42 PSI with a load (19 and 20" higher with 46 PSI loaded)

Well, Michelin disagrees with you on tire pressure. To be fair, the pressure differs across the different years, drivetrains and packages.


The door jamb says 36 front and rear but I found that to be too much in the rear and too little in the front due to wear patterns. Comfort suffers a little with higher air pressure in the front but MPG does not. I get 24-25 on the highway.

michelin make tyres and hope you wear them out fast - so under inflation is desirable (for them)
mercedes (allegedly know how to make cars) and understand the stresses and loads the car will likely be subjected too, and thus better know what you need to stay alive


your safety and indeed the insurance risk (and likely payout in a big claim) will be based on the car manufacturers idea of a good idea / safe settings, not some joker making round black things

They make tires that lasts 45,000 miles without rotation on a heavy car.

I hadn't realised this first bit. In 1943, the United States Supreme Court relieved Marconi of some of his U.S. patents in favour of the Englishman who discovered and tuned radio waves, recognising Marconi wasn't the early inventor of radio technology.

Don't go on holiday - that same Englishman submitted his results for publication in the form of a paper titled "On the Theory of Lightning Conductors," in which he clearly discusses the velocity, frequency, and wavelength of electromagnetic waves produced and detected in a circuit. Before the paper went to print, however, he discovered that Hertz had already published a memoir in which he described his efforts to generate and detect waves transmitted across space

and that same English guy made a major contribution to automotive engineering, when he invented the electric spark plug for the internal combustion engine...




.

Which shoved the diesel to the "back of the bus." I don't see that as a positive, but spilled milk and all that...

FYI - There's dual range (315 and 433) sensors out there. No idea how they work in actual practice.

autel do them now - I have a set of programmable 433mkz sensors... you stick them on a USB pad - select the brand and model and it beeps and flashes and tells them to be merc sensors, then you code the BT brain with the old codes

they JUST added BMW bike coding in an update last year

the later type I guess in the same way enables whichever of the 315 or the 433 frequency required - saves them needing two production items and helps the customers

note the correct spelling is tyre after all the first patented and then the first design of a practical pneumatic tyre were both invented by Scotsmen

https://www.ebay.co.uk/itm/164632511646?