Tyre pressure sensor false alarms

[Sotosound]

We currently own a 2014 V70 and a 2015 V60 and have found that the tyre pressure sensors tend to tell us there's a problem when there isn't.

A couple of weeks ago, the V60 suddenly declared that the pressure was low in all four tyres. Since we had not just driven over a police stinger, we didn't believe the warning. On checking the tyres, they were all fine.

Back in February, my own V70 declared low pressure in the n/s front tyre, although it was fine when I stopped at a filling station to check it.

A couple of weeks ago, the n/s rear tyre on my V70 was replaced and all the tyre pressures set to 270. After this, I calibrated the tyre pressure sensors. Last Friday, however, as we were trying to get home from Loddon in Suffolk in horrible traffic conditions, the V70 declared that the pressure in the n/s rear tyre was low. When we got stuck in a queue going into Newmarket (on the alternative route suggested by the Volvo sat nav), I pulled off the road and did a visual check. It looked fine. It continued to be fine all the way home and when I did check the pressure it was fine, and matched the other rear tyre.

Occasionally, the sensors get things right, but the high number of false alarms far outweighs the much smaller number of genuine issue reports. This effectively makes the sensors very unreliable witnesses.

What are other owners' experiences of Volvo tyre pressure sensors, and are our issues normal or an indication of a technical or electrical fault somewhere?

Thanks in advance.

[FreshAir]

I know you asked bout feedback on Volvo, but.... I had multiple VW/Skoda cars with it before the V70. Used to get false warnings from them as well.

I don't think I have it on my V70, as it did not detect a puncture I got 1 week after I got the car, which of course was too close to shoulder to be repaired.

[buick boy]

Had the same problem on my wife's car . It was the sensors fitted to the tyre valves . They are fitted with batteries , which will eventually die. As they were all fitted from new they all started to fail around the same time . You can fit new batteries but its a bit of a faff (there are a few videos on youtube that show you how ) . Easier to get your local tyre fitter to fit new one's . They are readily available on ebay .

[Sotosound]

Originally Posted by buick boy

Had the same problem on my wife's car . It was the sensors fitted to the tyre valves . They are fitted with batteries , which will eventually die. As they were all fitted from new they all started to fail around the same time . You can fit new batteries but its a bit of a faff (there are a few videos on youtube that show you how ) . Easier to get your local tyre fitter to fit new one's . They are readily available on ebay .

Many thanks.

That was a Volvo?

[Sotosound]

I've just found some information online.

Volvo says: -

The TPMS system uses the car's ABS system to monitor the tyre pressure levels. When the system detects an incorrect tyre pressure, the driver receives information in the driver display. The driver is also notified about which of the car's tyres has incorrect tyre pressure.

This is a description of "Indirect TPMS" (iTPMS), which actually uses the ABS system to detect when a tyre's rotational speed varies significantly from that stored when the system was last calibrated. It assumes that if the rotational speed is significantly different then the rolling radius is significantly different, implying that the tyre pressure must be significantly different, and acts accordingly by raising the alarm.

With iTPMS, there are no tyre pressure sensors, just an app. (Never would have thought that! Who'd just rely upon an app with no sensors when it comes to tyre safety?)

This suggests that the system could actually be affected by anything that significantly influences the rotational speed of one or more wheels, and also by anything that correctly or incorrectly suggests that rotational speed has been affected, and not just by an actual change in tyre pressure.

During my time as a programmer, I learned to always explicitly record important data values rather than trying to infer them from the values of other pieces of related data since inferences can be wrong whereas explicit values are always explicit. (Try calculating a credit for a VAT invoice wherein you know the gross invoice value but not the VAT or discount breakdowns.) It seems, however, that no-one at Volvo has learned the lesson of "Always record, never infer.".

How trustworthy, for instance, is the method of calculating rotational speed by using the ABS system? If that calculation isn't reliable then iTPMS will be receiving unreliable data. If I drive repeatedly around a large roundabout could I perhaps kick off a tyre pressure alarm for the two n/s tyres? After all, they will be rotating more quickly than the o/s pair.

Also, iTPMS itself uses just an app to work things out, and my guess is that the app is probably a bit bug-y (as many apps are), meaning that it could easily kick off for no good reason other than that some faulty logic might sometimes lead to the execution of the instruction to display the warning message when it's inappropriate to do so.

An then there are faulty readings to worry about. You should see the number of irrelevant warning messages that are triggered by a faulty ABS sensor.


For V70s, Volvo switched from Direct TPMS (dTPMS) to iTPMS from Chassis Number 255583 onward. My V70's Chassis Number is 325284, so it uses iTPMS. Lower maintenance than dTPMS, but very likely also lower reliability.

I've also similarly determined that my wife's V60 uses iTPMS.


Finally, here is what Volvo should have said: -

"The TPMS system uses the car's ABS system to monitor implied tyre pressure levels based upon wheel rotational speed calculations performed by the ABS system. When the system infers that a tyre pressure might be incorrect because the ABS system thinks that that tyre's rotational speed might be incorrect, the driver receives information in the driver display. The driver is also notified about which of the car's tyres might possibly have incorrect tyre pressure."

I'd describe iTPMS as a bit of a stretch.

[100K+]

I occasionally get a tyre pressure low warning,but have had so many false alarms, I now instantly request a system recalibration and the alarm message disappears. Im assuming if I had a puncture ie nail in tyre the message would return, and I would stop before I ruined the tyre. A blow out wouldn't be an issue waiting to recalibrate as the tyre would be fubar'ed already.
Cheers Bob

[Sotosound]

Originally Posted by 100K+

I occasionally get a tyre pressure low warning,but have had so many false alarms, I now instantly request a system recalibration and the alarm message disappears. Im assuming if I had a puncture ie nail in tyre the message would return, and I would stop before I ruined the tyre. A blow out wouldn't be an issue waiting to recalibrate as the tyre would be fubar'ed already.
Cheers Bob

Last Friday, I tried to trigger a recalibration while on the move to see whether or not the message returned, but the car wouldn't allow it.

[Goldfish888]

I acquired my XC70 since June no Tyre sensor warning until I put 2 new tyres on the front and moved one of the good tyre to the back a few weeks ago . I now get tyre warning on dash every couple of 100mls And when I physically checked the tyre pressures they were all ok. When the symbol comes up on the dash, it worries me a lot in case I has a puncture. Very annoying problem . Hope anyone has an idea how to fix it. Think my car has an ITPMS system fitted

[100K+]

Originally Posted by Sotosound

Last Friday, I tried to trigger a recalibration while on the move to see whether or not the message returned, but the car wouldn't allow it.

Never had an issue with not instantly recalibration...
Next time it happens I'll try n remember to post exactly how I do it....
Cheers Bob

[Sotosound]

Originally Posted by Goldfish888

I acquired my XC70 since June no Tyre sensor warning until I put 2 new tyres on the front and moved one of the good tyre to the back a few weeks ago . I now get tyre warning on dash every couple of 100mls And when I physically checked the tyre pressures they were all ok. When the symbol comes up on the dash, it worries me a lot in case I has a puncture. Very annoying problem . Hope anyone has an idea how to fix it. Think my car has an ITPMS system fitted

If you do anything tyre-wise, it's necessary to re-calibrate the tyre pressures afterwards using the option in the My Car menu. This tells the car what the new "normal" is, and sets the baseline against which it can then look for any deviations.

So, set your tyre pressures correctly and then re-calibrate.