Tyre Pressure Monitoring System Issue

[qrt31]

Periodically the TPMS warning will come on. Invariably (except for one time when I already knew there was an issue), the tyre pressure is fine. I've asked the dealer to take a look under warranty but they say that I will need to pay £180 if they don't find an issue. It seems unlikely that the issue will happen when it is at the dealer, so I don't want to pay a fee for nothing. I called Volvo. I asked what the minimum tyre pressure is to set off the warning, but they could not tell me. Obviously somebody knows, so that is disappointing. They also said that I would have to pay the diagnostic fee regardless of whether an issue is found or not. Given that this is a warranty issue, this is problematic. When I had an Audi they were much more willing to investigate under warranty without a fee. My wife had exactly the same thing with her Audi, and they never charged her to take a look - even out of warranty. I suppose I could ignore it, but I worry that there will be a time when it not a false positive.

So, two questions: 1) Has anybody had this issue? 2) Does anybody know the tyre pressure that would normally set off the system?

Thanks.

Kurt

[JFDIT]

I assume you have done a couple of full resets?

I've had a couple of punctures and it's been around 5lb difference for TPMS to trigger. Go to a different dealership!

[eugen61]

Volvo’s TPMS doesn’t measure the actual air pressure inside the tires. Instead, it uses an indirect method by monitoring the number of tire rotations. This data is compared to the baseline saved by the driver in the car’s settings menu. When a tire loses pressure, it becomes slightly flatter, causing it to rotate more frequently than the properly inflated tires. This triggers the ‘Low Tire Pressure’ warning.

The data is processed by the ESP module, so issues with the warning system could stem from software glitch or improper calibration. Given the critical role of ESP (Electronic Stability Program) in safely driving your 400 HP car, it would be a wise decision to run a diagnostic check on the system to ensure it’s functioning correctly.

[jmw]

Yes, we’ve experienced the same issue on several occasions in 2 different XC40s BEVs. All 4 tyres showing as under pressure. It usually happens during >100 mile trips, not during short runs.

When it started happening we’d stop to check the pressures which were always fine. Now I just ignore it and reset the TPMS unless it’s showing an issue with 1 tyre (which has never been a false alarm).

[Ruby12345#]

It’s a poor system we had a Renault Kadjar it worked on tyre pressure.. In the 6 years we owned it was faultless, unlike the Volvo had the alarm go off checked tyres all ok.. I

[Felindre]

Again with the "Volvo TPMS" it's not unique to Volvo, just about every manufacturer uses this system unless you pay for the more expensive system with transmitters and receivers.

[JFDIT]

And the transmitters fail and their batteries pack up around
7 years or so requiring expensive replacement of the whole unit in each wheel. And people tend to "trust" the displayed tyre pressures rather than manually checking, which they are told not to do.
iTPMS uses the ABS components to calculate when a tyre goes flat. Simple, reliable and cost effective.

[qrt31]

Dealer indicates that since the system is based on tire circumference, having newer and older tires on opposite sides will throw off the readings, which is the case with me. Have had to replace the two tires on the passenger side this year, so they are 7mm, while drivers side is 4mm. Will likely keep getting the warning light unless I replace the other two perfectly good tires. I am loathe to pay more than £500 just to address the rubbish system Volvo uses. Could just keep ignoring, but that runs the risk of ignoring a real problem.

[eugen61]

Having newer and older tires on opposite sides of the same axle creates uneven grip, which can affect both emergency braking efficiency and overall stability. During hard braking, the side with less grip will trigger ABS intervention earlier than the side with more grip, leading to reduced braking performance and potential instability. For safety, it’s always better to use tires with similar wear levels on the same axle.

[JFDIT]

The iTPMS takes time to register each wheels rotation pattern in respect to the others under different driving situations when you perform a reset. So cannot see, however unwise, having worn tyres on one side would cause the false warning. I assume you have performed a full reset and driven the car until the new setting is recorded and stored?