2016 base Cayenne owner (well, actually lessee) here. I've driven lots of Porsches over the past 51 years but this is my first one with TPMS. It is the stock version and came on the car when new.

As I understand it the device is programmed to display an alert when the pressure drops 4 pounds or more below the suggested (on the sticker on the driver's door) pressure for a specific tire. Which it does.

But lately it's been displaying the alert and when I check the pressure on that specific wheel while driving the pressure is not displayed as low. I assume the pressure rises as the car is driven. But when I stop and restart the car the alert is back, even when I am driving and the display indicates the pressure is above the 4 pound threshold.

Is this normal behavior?

 

TPMS alert does not go by the suggested pressure on the placard. It goes by the pressure you set and program it to that pressure. It will alert you from the deviation you set whatever the pressure it. That's my understand, someone can correct me if I'm wrong.

 

You need to set it at the spec when the tires are cold. Then select the adjust option. Drive for a bit and everything should be cleared.

 

As I understand it the alert comes already set based on the pressures on the placard.

 

On my 2017S you select the Tire Size, and the Load. The Alert Pressure values are not alterable. If for some reason the pressure gets low and it Alerts, you'll add more air to that tire and it'll take a while for the TPMS to read that pressure and stop alerting you.

 

Thanks. That also seems to be the case with my 2016 base. I have gone into the various menus and submenus and found no way to change the Alert Pressure values.

 

 

Yes, and this is what makes me grind my teeth. I will get a warning on say the front right, however, once I have driven on the expressway for a few miles the system shows both front tires at the same psi. Oh well, maybe this will be fixed in the next firmware update.

Thanks for the replies.

 

 

 

 

iCarScan can read the battery condition.

 

OP here, Updating: I took my Cayenne in to the dealer this morning because the TPMS was showing an 'underinflation' warning when the car had been running on the expressway and the tires all looked to be within normal limits when viewing the tire pressure screen on the dash display. They had re-inflated the tires a couple of weeks ago and I thought maybe they had done it while the tires were warm and once they cooled down I was getting the warning, or maybe their tire pressure gauge didn't agree with the car's measuring system.

I was told there is a recent TSB on this subject. I wasn't told exactly what it said but apparently there is some recognition that the TPMS can be a bit, errr, squirrelly. I learned that if the car is stationary you can go through the screens on the tire pressure display and get to a screen that shows you a more detailed picture of which tire(s) the system thinks is/are underinflated at that particular point in time and by how much. I'm still thinking about how this information might be helpful but there you have it.