ilke.senol

I own a 2013 ML350 4Matic bluefficiency with run-flat capability tires. There is tire pressure loss warning system but I cannot see the individual tire pressure on the display. Is it because of some settings on onboard computer or is it because I don't have this capability in the car? I do not have additional nut on tires where the air hose. I believe the system measure the tire pressure bu rotation wirelessly. Can I not have this option?

Thanks

YYZ-E55

You probably have passive tire pressure monitoring (code 477) which measures the tire pressure based on the rolling resistance (as calculated by the wheel speed sensors). Code 475 includes the sensors in each wheel with the unique valve stem and the digital display on the instrument cluster.

ilke.senol

Yeap, I have just checked and I can see that the code for tire pressure loss warning system is 477. That means I will not be able to see the tire pressure in each tire. How about if I change my wheels to those with sensors in each of them? Would that be enough or is still some software update required?

another_geek

You would also have to add both the sensors in the wheels and the RF radio receivers in the wheel wells to receive the signal from the wheel sensors. Then you would have to figure out how to reprogram the COMMAND system to recognize the added receivers.

Probably not impossible, but very difficult.

Pitazorro

Hi, I also have warnings after restarting the run-flat system after 6-7 days. My tires are normal Pirellis, not run-flat tires (I have 20" AMG wheels). The warning says to check the tire pressure and restart the run-flat. When I measure the pressure, there is only 1 PSI difference among the tires. Is this system that sensitive to notice such 1 PSI difference? I also hit the front left wheel to the pavement and some scratch and 1ml volume rubber is teared apart from the tire close to the wheel (there is no air leak). By the way I couldn't have my tire changed because they cannot suply it to Europe.

iankayem

You will have to change all four tyres to ensure the system does not give a warning. Even if you replaced one with the same make/size/model, the different diameter of new versus worn tyre could set it off.

A purist may say otherwise, but I have full respect for this system.

I got the warning on my last car. I got out and visually inspected the tyres, and decided it was a flse alarm.

I reset the warning drove on. Next day I got another warning and visually they were all ok. So out with the trusty gauge and found one was down by 4psi.

With no warning, I would have driven on while the tyre leaked down further, eventually heating up and giving a blow out.

With the puncture repaired, we continued with happy motoring, later replacing all four together when the originals wore out.

ilke.senol

First thing comes to my mind is the balance. After hitting a pavement, you may have altered the balance and that may cause alarm. Another less likely reason can be the age of tires. if one is older and worn more than the others the system might react on it.