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Erroneous TPMS alert

Posted: Mon Sep 03, 2018 11:29 am
by Gel
Has anyone had this experience am seeing as in image below. :?:
It's certainly not cold today.

Tyrefp.png


Re: Erroneous TPMS alert

Posted: Mon Sep 03, 2018 12:51 pm
by DaveBerlin
Hi Gel, you certainly find some “Funnies” take a look at these pages from the Manual - hope it helps you Dave :D

1F0C13E0-32C8-4397-9740-3365D0FAFD16.jpeg

4AC7C4E1-32DC-4398-82B2-2ACB9CE8347B.jpeg


Re: Erroneous TPMS alert

Posted: Mon Sep 03, 2018 1:28 pm
by Gel
Checked manual Dave, and may go through re setting procedure if it doesn't clear itself.

Re: Erroneous TPMS alert

Posted: Mon Sep 03, 2018 2:16 pm
by switchback
I might have to calibrate mine as well. Ever since I had a new battery fitted the indicated tyre pressures have been low when compared to my gauges which previously matched. From what I've worked out, you set the tyres to the "target pressure" 33/30 when the ambient temperature is at 21 degrees Celsius (cold). Have I got this right?

Re: Erroneous TPMS alert

Posted: Mon Sep 03, 2018 3:01 pm
by chrisw99
I once got that, and when I checked the actual tyres themselves with an inflator, turned out the one it was complaining about was indeed a couple of psi down on where it should be, so it wasn't erroneous for me.

Re: Erroneous TPMS alert

Posted: Fri Sep 14, 2018 2:13 pm
by Gel
To finalise my issue, glad to say that the faulty TPMS message cleared itself after few days.

Re: Erroneous TPMS alert

Posted: Thu Sep 20, 2018 12:58 am
by jet
Had the Low pressure warning on FL tire for the first time last week. Reset/Calibrated the TPMS through the menu (without changing tire pressure) and the warning disappeared.
As mentioned in the owners' manual and described in details in this document, pages 104-110, to avoid a situation where a hot tire that is underinflated might appear to be fine, because the contained air pressure is at or above its cold inflation pressure, some sort of temperature compensation is done by the system.

Here is a wild guess: I assume this compensation is based on a hardcoded table/algorithm valid for tires filled with air. When tire is filled with nitrogen, the compensation becomes less accurate, hence the false warnings.

The TMPS behaviour that you have experienced is explained on p.110 of the above document:
System E had a different approach. When the user sets the tire pressures and initializes the system,
the pressure is referenced to the current tire air temperature, which is equal to the current ambient
temperature as well. If the system senses the tire temperature being more than 36°F (20°C) below
the initialization temperature for more than two weeks, the system sets off a warning and must be
reinitialized. The user is advised to recheck tire pressures (cold) and must reset the system at the new
temperature.