Tire Pressure Warning System Turn-on Threshold

[Joey K]

Greeting Forum members. I have an '06 GS-300 AWD with runflat tires. The tire pressure warning system activated today and I checked all four tires with a mechanical guage. The four tires were all within 35 PSI +/- a pound. My question is: What is the lower pressure limit at which the system is supposed to activate?

I have had this same issue before and the dealer "took care of it" by putting all four tires at 40 PSI which I think is too much but I could be wrong. Any information would be greatly appreciated.

Joe

[Duckman]

35 PSI seems pretty high to trigger the sensors. I have had my car for just over a year and my sensors have gone off twice. Both times...I started the car the morning after it had to sit outside all night...and it was one of the first cold nights of the fall.

This weekend, I had to go out of town and so the car was in a hotel parking lot all night. Saturday morning, it was 42 degrees. I turn the car on and sure enough...low tire warning. I checked the pressure...all 4 tires were at 28PSI. Filled up the tires to 34PSI and the sensors turned off. It was the same situation last fall.

Unfortunately, I don't have a base to start with. I never checked the pressure before I had the car out all night. Needless to say, I filled up my tires to a point which is less than yours, and my sensors turned off. Maybe the sensors can have the sensitivity adjusted, and yours are more sensitive?

--Duckman

[Joey K]

Hi Duckman,

I did some further research and found that there is a small switch on the lower lip of the driver's side dash. The consensus was that the four tires needed to be set to spec and then this switch needed to be pressed, while the ignition is on, until the tire warning indicator flashed three times. This action apparently reinitializes the system at the current tire pressure level and then monitoring is resumed from that point forward.

After turning the car off and then on again the light is now extinguished. My wife was upset (who'd guess) that I "fixed" it because she and my daughter were looking forward to ice cream and donuts on the weekend.

[Duckman]

Cool! Resetting the system should allow you to keep your PSI a little lower. My tires, which are Dunlop Run Flats, state that they can be inflated to 51PSI, but I have been told to keep it to between 33 and 36 PSI.

I had to laugh at your last comment. My two daughters love it when I have to go in for oil changes. They run to the car knowing full well that donut holes and juice are waiting for them at the dealership.

--Duckman

[steviej]

I think the lower limit is 28 psi. Now I can't remember if the 28 is the actual point or I am thinking 28 because the lower limit is 4 psi below what the initialization point is. Since my set point was 32 psi, 4 psi below that is 28.

Winter reminder: Tires lose 1 lb of pressure for every 10 degree drop in outside air temperature. You will have to add air or reset your sensors as the air temps get cold. If you live in a place like souther Florida, then :P

steviej

[The G Man]

Dont read max pressure on the tires itself, look at the manufacturer's recommanded tire pressure which is on your door dam. It recommands 32 PSI for the Dunlop run-flats.