W209 TPMS Question
Member
Joined: Nov 2015
Posts: 242
Likes: 26
From: US
Own 2005 CLK500, but drive 2011 Sienna :)
What I don’t get- how it may follow the sensor if the receiver is in the trunk? From what I understood in this tread - there are no individual receivers in each wheel well (this would be the logical way for problem to follow the nad sensor). So if there is one and only rececing antenna in the trunk - how does it know which side wheel the signal is coming from?
MBWorld Fanatic!
Joined: Jun 2008
Posts: 1,227
Likes: 61
From: Atlanta Metro
2008 clk550 - Navigator - Frontier
What I don’t get- how it may follow the sensor if the receiver is in the trunk? From what I understood in this tread - there are no individual receivers in each wheel well (this would be the logical way for problem to follow the nad sensor). So if there is one and only rececing antenna in the trunk - how does it know which side wheel the signal is coming from?
But I don't really know.....
Member
Joined: Nov 2015
Posts: 242
Likes: 26
From: US
Own 2005 CLK500, but drive 2011 Sienna :)
Here is a guess..... When there is a low tire pressure situation, the warning is simply "check tire pressure", not identifying a specific tire. I believe this is because the car is looking at the "relative" balance between the tire pressure signals relative to the when you did the last reset of the same. I can see it detecting that a sensor is not transmitting at all and identifying it as bad. If the signal is just weak, the system would likely just report "check tire pressure".
But I don't really know.....
But I don't really know.....
MBWorld Fanatic!
Joined: Jun 2008
Posts: 1,227
Likes: 61
From: Atlanta Metro
2008 clk550 - Navigator - Frontier
An indirect TPMS typically relies on wheel speed sensors that the anti-lock brake system uses. These sensors measure the rate of revolution each wheel is making and can be used by on-board computer systems to compare with each other and to other vehicle operation data such as speed.
Based on the rate of revolution of each wheel, the computer can interpret the relative size of the tires on your vehicle. When a wheel starts spinning faster than expected, the computer calculates that the tire is underinflated and alert the driver accordingly.
So, an indirect tire pressure monitoring system doesn’t actually measure tire pressure. It’s not electronically processing the same kind of measurement you might see with a tire gauge. Instead, an indirect tire pressure monitor simply measures how fast your tires are rotating and sends signals to the computer that will actuate the indicator light when something in the rotation seems amiss.
Maybe this "how stuff works" excerpt helps.
Based on the rate of revolution of each wheel, the computer can interpret the relative size of the tires on your vehicle. When a wheel starts spinning faster than expected, the computer calculates that the tire is underinflated and alert the driver accordingly.
So, an indirect tire pressure monitoring system doesn’t actually measure tire pressure. It’s not electronically processing the same kind of measurement you might see with a tire gauge. Instead, an indirect tire pressure monitor simply measures how fast your tires are rotating and sends signals to the computer that will actuate the indicator light when something in the rotation seems amiss.
Maybe this "how stuff works" excerpt helps.
