Tire Pressure Sensor Warning Setpoint

[RhoXS]

The set point at which the tire pressure warning light illuminates is apparently a function of the lowest tire pressure when the system is registered. How much below the lowest pressure does the light come on?

[pauljcl]

The set point at which the tire pressure warning light illuminates is apparently a function of the lowest tire pressure when the system is registered. How much below the lowest pressure does the light come on?

I am not sure this will be of much help, but here goes:

When I got my 'new' 09RX, the first evening the tire press. warning light went off, as it got cooler. Tires were at 25-26psi. The car had been at the dealer for a while before he sold it, and had been 'prepared' a few months before. I would assume that the 'preparation' includes correct (i.e. 30)psi setting and re-set of the TPMS. Thus, I would guess that the warning light comes on about 4-5psi below where set. [i am sure the dealer would know]. I use 32-33psi, but have left the TPMS un=reset, because a) I'm pretty good at checking tire ressures regularly, and B) I don't want to be bothered by a possible TPMS warning (if the weather has a cold snap).I am really only using it as warning in case of a puncture or other similar problem occurring, thus a 'margin' of 7-8 psi is fine with me.

Of course, the 'simple' way to verify is to progressively deflate a tire (say, the spare) and see where/when the warning light goes on..... Simpler yet, as mentioned, is a tel. call to the dealer. Good luck!

[pauljcl]

The set point at which the tire pressure warning light illuminates is apparently a function of the lowest tire pressure when the system is registered. How much below the lowest pressure does the light come on?

Actually, this brings on another question.... If all tires are at, say, 32 psi, but the spare is at , say 25 psi, and the TPMS is re-set, does it really reset for all tires based on the lowest?