It is especially bad with the early GLs and their dumb TPMS. If one of the sensors goes bad, you have to resort to round-robin replacing with a known good TPMS. I keep a spare set of wheels, so this is less laborious than it might be, but still it's a pain, especially because the system takes some number of miles to report that one of the sensors is not transmitting.

I bought four Chinesium sensors when I got a set of four snow tires. One of the sensors began intermittently failing to transmit. I isolated the sensor and had a tire shop peel the tire and re-mount after swapping the sensor. A couple of thousand miles later, failure again. I couldn't believe it was either the new sensor or one more of the old, so I investigated the TPMS module and antenna. News flash: The antenna is under an underbody panel that has a ridiculous number of fasteners holding it on. Both looked reasonable, so I started the round-robin wheel replacement again. Sigh. Yes it's one more of the Chinesium sensors. At least now I know which it is.

But to aggravate me even further: Yet another of the sensors is dying, intermittently failing to transmit. Probably one of the other Chinesium, right? So I should just replace all the rest, right? But unfortunately, of my set of five additional wheels, one of them contains the spare Chinesium that I got as a freebie to replace the failing one - and I don't know which wheel it is on.

Get first-quality sensors. These Chinesium apparently last only about 20K miles best case. Rock Auto sells only the BH (which stands for Baolong Huf, but I can only hope they know what they are doing), and TPMSDirect sells Huf. I note that Siemens sensors apparently are not sold anymore. Given the narrow window in which these motion-activated 433MHz sensors were installed, I would not be surprised to find them out of production before too much more time goes by.

 

Replaced two tpms sensors one week ago at discount tire ($131 after tax).
The other two are still working. its amazing that those original sensors lasted 17 years (115k miles).
The original sensors are "Siemens VDO Daimer Chrysler 433.92MHz"
Discount tires used the "BHsens Intellisens UVS7050 73.913.750 315/433MHz" sensors.
No programing was performed and the "tire pressure monitor inoperative" warning message is gone.

 

Probably the only thing stopping me from going the Discount Tire route is the fact there is no Discount Tire shop in my town.

I ordered a set of four Huf sensors, which should be the same as the BH, as the H stands for Huf and the picture on Rock Auto shows a Huf marking. I hope they build them to the standards of the Siemens.

The sensors go to sleep when the wheel is not turning, but still - 117K is over three thousand hours of transmitting.

 

I got an activator/reader off Amazon for under $20 a few years ago. You just hold it next to the valve stem and hit the button. It will activate the sensor and show the psi and temp of that tire. Makes it easy identify which sensor is not working. So far its worked on several makes/models, including my GL450. Total pain figuring out which one if the car doesn't show individual tires. Mine is an ATEQ VT31, which has been discontinued, this is the replacement for $42. There's still options for much cheaper, but I cant say they work on MB.

ATEQ VT5s Universal TPMS Sensor Activator and Trigger Tool for TPMS Resets - compatible with Domestic and European vehicles equipped with TPMS https://a.co/d/71BDWbq

 

07-09 (I think) pressure sensors go to sleep and are only awakened by the tire rolling. The tire shop could not wake them up with their tool. They are dumb sensors, which probably contributes to their longevity.

Unless they are 100% pure Chinesium, that is.

 

Mine works on my 2008 GL450. Might have to drive 15-20 mph, then check as soon as you stop. At the tire shop it probably sat for a bit, and driving it in the shop wasn't fast enough to wake them up.

 

Oh I get it. Wake the sensors up, then check to see which one is not transmitting. Seems legit.

How does it tell you it is receiving a signal?

 

How would you know you are not receiving the signal from one of the other wheels?

 

it has to be pretty close to pick it up. Its got a little LCD screen that shows PSI and and temp. If it shows nothing, the sensor is not transmitting.

 

Unfortunately, the cheap units apparently only send the activation signal. It is the $100-$200 units that receive and display the signal.