paulfromtulsa

how are the tire pressure sensors mounted in the stock wheels? i have a set of aftermarket wheels coming and was wondering how hard it would be to mount the sensors in them? any suggestions from the people that have done this?

whoover

If the wheels are compatible, you just unscrew the sensors and swap them. If the wheels are not TPMS-compatible, you're kind of stuck. But most wheels nowadays are compatible.

I think you're supposed to use new o-rings or something, but tire places have the required parts in stock.

Jrocket

Look in the tire and wheel section here on the boards.Get Luke from Tireracks ext. and call him,he will get you the right TPMS to use with your wheels and a fraction of what the dealer charges.

Patentmat

Kind of but not completely. If they will not fit, you can always use a metal clamp around the inside of the rim to secure the sensor, MB actually suggested and did this for me.

VTen555

depending on your year and model car it may not need sensors. If its a passive system like my car was it won't need them.

dfresh101

Yeah mine doesnt have sensors either.

joeybenz106

any one know how much the new sensors would cost?

Blood Doctor

Dumb questions, but...

How does a passive system work ? Are the CLS passive or have TPMS ?

Thanks

blackcls63

the 55's (what you have) is passive... its some sort of calculation based on the standard rate of rotation of the wheels vs the rate it rotates with less air pressure...

the 63's i know for a fact have actual physical tire pressure sensors, meaning you dont have to be in motion for the computer to calculate whether you have a flat/less air in the tire(s)...

jpohl402

What about 2005 E55's?

Centurion

So is this something that needs to be removed from the OEM wheels and installed into the new, aftermarket wheels?

Blood Doctor

if you have tpms, you can have a tire shop carefully remove & remount the oem sensors into your new wheels, or buy a new set of sensors and have them matched to your car if you don't want to dismount our old tires.

tire rack has a good section on this.

Ak63

Does your 63 shows the actual psi for each tire? I can only get to the screen that shows "tire pressure senors active", and nothing else. And the owner's manual is so useless.

m_berman

My 55 shows psi for ea tire. I verified the reading within .5 psi accuracy for each tire with a digital tire presssure guage.

wmhjr

Read your manual. In '07 and '08 in the US, the TPMS does not show pressures - only that it's OK or not OK. Now, if you drive a little further north in canada they will magically work

Ak63

Is this due to different sensors use between US and Canada models?

This passive way of displaying Ok or not Ok is terrible, because by the time I get any warnings for low tire pressue, it will be too late. I guess I'll go with my traditional accutire gauge to make sure the pressures don't drop below the dangerous level that can damage the wheel.

modulus

If you have the TPMS that reads out the actual pressures of each wheel like the CL class, the valves are metal. If you have the passive type the valves are the usual rubber. The passive I believe uses the ABS to measure wheel rotation, so if the vehicle is going straight and one wheel is turning faster it must be losing pressure. My '06 CLS55 has passive TPMS. Hope this helps.

Inf4life

What if you have 3 metal ones and one rubber one??

wmhjr

No, it's simply due to the TPMS software configuration being different in the US vs Canada. Just like how in Canada you can get rear heated seats and other options for the W211 that are not available in the US. Or, memory seats, C350 4Matic, etc which are also available in Canada but not the US. Here in the US we pay a bit less, but we also get quite a bit less.

Ak63

So if it is just software configuration, can the stealer update the software for US cars to display actual tire pressures?

wmhjr

Sorry, but I don't know the answer to that one.