Tire Pressure Monitoring System 2003 Q45

[Dachristianman]

So during this week's drop in temperature, my tire pressure monitoring system illuminated. I'm not getting readings from any of the tires. Once it warmed up, the system woke back up and I received readings from all 4 tires again. The next morning when the temperature dropped again, I was back to no readings.

Any ideas on what is causing this?

Tom

[PapaSmurf2k3]

Usually it takes a little while for the readings to come online. I know in the latest Q50 I drove, you had to actually move the vehicle about a mile or so before they'd come onilne. Maybe the tires heated up a bit in that small time window, I'm not sure... but it actually had a message saying "pressure readings will appear while the vehicle is in motion".
So it sounds normal.

[Q451990]

Sounds about right... our G just has the idiot light, but it always takes a little bit of driving before the light either comes on (if the tires are low) or turns off after topping them off. We joke that it's the "first cold morning" warning light. Comes on every year.

I think the rule of thumb is that your tire pressure will drop 1 PSI for every 10 degrees of ambient temperature change...

Heath

[Dachristianman]

That's odd. I added air to the tires and the light went out, but it's still not displaying the tire pressures on my screen. Does the system read ** on all 4 tires every time you start the car until you drive for a few miles? I'm struggling with this one because many of my trips are less than 2 miles.

Tom

[PapaSmurf2k3]

Switch (on/off) communication is easier and faster than variable information (32psi, or 30psi, etc).
I assume there's the initial "good/bad" that is very quick, followed by the actual pressure reading after a lot of other systems are loaded.

[Rogue One]

That's odd. I added air to the tires and the light went out, but it's still not displaying the tire pressures on my screen. Does the system read ** on all 4 tires every time you start the car until you drive for a few miles? I'm struggling with this one because many of my trips are less than 2 miles.

Tom

In short, yes. In order to give an accurate reading, you have to drive the vehicle at least two miles. Your short trips aren't long enough for the system to take a reading. Not worth stressing over.