Tyre pressure monitor
Thread Starter
Super Member
Joined: Nov 2021
Posts: 893
Likes: 397
From: Hong Kong, China
2021 S450 4Matic
Tyre pressure monitor
The W223 tyre pressure monitoring system is seemingly only able to report the 4 tyre pressures a few minutes after starting the car. But by then, the car will be driven around and the reported set of tyre pressures is no longer applicable for 'cold' tyres but rather warmed up tyres, I suppose.
Am I missing something? Am I supposed to let the car sit idling for a while until the monitoring system does its job?
Is there a way to work around this? At present, I use a physical guage.
Am I missing something? Am I supposed to let the car sit idling for a while until the monitoring system does its job?
Is there a way to work around this? At present, I use a physical guage.
Member
Joined: May 2010
Posts: 118
Likes: 39
From: Maryland
'71 280SL /'25 AMG SL63 SE/'24 AMG S63 SE Edition 1/'25 Maybach GLS600/'20 Toyota Sien
Cold weather reduces the tire pressure temporarily. You need to drive the car for a few for it to recalibrate. It will not calibrate sitting still. Also, in very cold weather, you will need to drive for about 40 minutes to get the tires warmed up and get an accurate reading.
MBWorld Fanatic!
Joined: Dec 2006
Posts: 6,499
Likes: 335
From: Europe
223.168 & 213.012 & 906.633 & 214.005
No cold weather in Hong Kong but the tyre pressure monitoring sensors would only activate in motion, does not help waiting a while before starting to drive. Used to be different years ago with Beru sensors or the like.
MBWorld Fanatic!
Joined: Dec 2006
Posts: 6,499
Likes: 335
From: Europe
223.168 & 213.012 & 906.633 & 214.005
I wouldn't use a gauge. You might have a quick look at tyres to see if any are completely flat (the new system would give a warning too late). Even if the tyre was severely underinflated, the first reading from the cluster would be safe. The manual says the the tyre pressure readings can be considered as from a cold tyre if you have not driven more than 1.6 km (a funny figure, must be coming from a US manual). You should see tyre temperatures too from the cluster to judge tyre pressures for warm tyres.
Thread Starter
Super Member
Joined: Nov 2021
Posts: 893
Likes: 397
From: Hong Kong, China
2021 S450 4Matic
I wouldn't use a gauge. You might have a quick look at tyres to see if any are completely flat (the new system would give a warning too late). Even if the tyre was severely underinflated, the first reading from the cluster would be safe. The manual says the the tyre pressure readings can be considered as from a cold tyre if you have not driven more than 1.6 km (a funny figure, must be coming from a US manual). You should see tyre temperatures too from the cluster to judge tyre pressures for warm tyres.
My gauge is quite accurate and agrees well with the air pump at local gas station.
Now I will have to compare the car's tyre pressure figures with them.
Trending Topics
Out Of Control!!
Joined: Nov 2018
Posts: 11,432
Likes: 5,343
From: San Francisco Bay Area
2019 C63CS
That is normal with sensors that go to sleep when motionless to preserve the battery. Rotating the wheels will wake them up and eventually the pressure information shows up in the dash. Should be within the first mile of driving. Today's sensors are also self-learning, so you don't have to get them coded if you use winter and summer wheels. They establish communication automatically, which is part of why it takes a moment. Tires are considered cold if not driven for at least 3 hours, or no more than 1 mile, that's where the 1.6 km comes from. That's 1 mile. However, the TPMS sensors are really not meant for accurately setting your tire pressures. They only have an accuracy to within 1 psi. They are more of a piece of mind and a smoke check to determine if the pressures are roughly as expected, and in my AMG I'm mainly interested in the tire temperatures they report so I can gauge grip level.
Last edited by superswiss; Jan 26, 2022 at 01:38 PM.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Out Of Control!!
Joined: Nov 2018
Posts: 11,432
Likes: 5,343
From: San Francisco Bay Area
2019 C63CS
Correct, you won't get an alert right away, but a deflation that severe is hard to miss with a quick visual check, or feel something is wrong the moment you start moving.
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
