Tyre Pressure Loss Indicator issue

14th November 2021

Tire Pressure Loss Indictor Warning Light

Before I purchased my GTI, on the test drive, I noticed that the Tyre Pressure Loss Indicator warning light was on. I imagined that a tyre might need some air adding, there might be a puncture or even a new tyre might be required. This didn't put me off buying the car.

Once purchased, I adjusted all the tyres' pressures and reset the system. However, a few days later the warning light returned: rear right tyre. I checked the tyre pressures were still ok and reset the system again. After another few days, the warning light reappeared, the rear-right tyre again. I decided that the rear right tyre must have a slow puncture so I took the car to a tyre shop for them to take a look, but they could not find anything! The GTE doesn't come with a spare tyre and not having a car without a spare before, I felt it was important I could trust the low pressure loss indicator system. So I kept a close eye on things and over time, grew confident that my tyres were actually fine and that it must be the warning system that was faulty.

Usually, it was the rear-right tyre which was indicated as loosing pressure, however sometimes it would report the rear-left. Also, occasionally I was unable to reset the system after the warning light appeared. On one occasion the message "Tyre Pressures could not be stored" was displayed in the dash and the warning light flashed for a while. The manual says this is an indication of a system fault and I need to seek expert assistance. I decided to wait until the car went in for it's next service and ask them to investigate.

My understanding is that the Tyre Pressure Loss Indicator (TPLI) system uses the ABS wheel speed sensors on each wheel. After the tyre pressures have been set correctly and the system reset, if it subsequently detects that one wheel is rotating faster than the others, then it assumes it must have lost pressure. I therefore began fearing that there could be a fault with the ABS control module! Could be expensive :-(

My car went to a local VW dealer a few weeks ago for a routine service and after investigating the issue they suggested that it was because the rear left tyre was a different brand (Continental ContiSport) and had much less tread (approx 3mm) compared with the rear right tyre (Michelin Primacy 4 with about 6mm tread). I was a little skeptical that this could be the cause of the problem but since the Continental tyre's tread was getting a bit low, I was happy to replace it and see if this fixed the problem. One replacement Michelin Primacy 4 tyre (approx. £100 from Kwik Fit) fitted and I've never seen the warning light since! :-)