Hi guys when I started my 09 GS 350 last night the tire pressure light was on so I checked all 4 tires and didn't notice any of them low and as I drove the light came off by itself. Does the light tell you which tire is low or do you have to figure that out yourself? I believe my car has Dunlop Sport tires.

 

No, it does not tell you which tire, and this problem is much more common in the cold weather. Just add couple of lbs all around.

 

you got to figure it out for yourself unless you have a scan tool, then you will be able to know which tire/sensor is setting off the light.

As the outside air temperature drops, it is pretty common for TPMS lights to come on. The air pressure in the tires will drop 1 psi for every 10 degree drop in temperature. You probably have at least one tire that is "low". As you drove, the air temp in the tire rose just enought to increase the psi just enough so the sensor registered the pressure as "not low" and the light went out.

just add a little air to all. At this time of year, being in New England, I bring the pressures back to 32 psi on the first day with temps less than 40°F.

steviej