tomiv9

Anyone know what pressure level triggers the low tire pressure alert? I have a 2009 IS 250 AWD, 17" all around. Alert just came on, tires all seem to be about 32 psi, one closer to 30. Had the car for 4 years never had this happen before. Thanks.

SC400MAN

iTrader: (1)

You can set/reset them on your car using the toggle switch on the let of the steering wheel. Consult your owners manual.

swfla

iTrader: (1)

If you've physically checked all five tires, including spare and they're as you say, you may have a low sensor battery. They usually last more than four years though. As mentioned, there's a reset button under the dash near the steering column. It's more likely you just need to do a reset after you've inflated all tires to your desired pressure.

tomiv9

Ok thanks. I was trying to figure it out if there is actually a problem with the one tire, or if they are all just a little low, or if its the sensor. I think i'll inflate them all and monitor. Thanks

swfla

iTrader: (1)

Not sure what the actual low pressure trigger is, but it's at least 5 psi below the setting on tpms.

WylieKylie

iTrader: (2)

The trigger for turning on the light is somewhere around 30psi, so if you found one at 30psi that is likely the one that set it off.

Cali2is

I've seen mine light up at 28psi

Gville350

iTrader: (10)

Yep, ~28 psi I've seen as well.

iNfectious

iTrader: (6)

Mine's around 30. You can check it via Techstream software.

Bichon

A low battery on the sensor should give a "check system" error, not "low tire".

The spare does not have a sensor in it.

tomiv9

Thanks I figured the doughnut didn't have a sensor. The alert went away as the day warmed up but came back the next morning. Think its just the temp drop. Got new tires in june. I put a couple lbs in each one and been good to go. Just weird this never happened before. Always worried it could be some other issue. Thanks again.

Gregz_IS

TPMS sensor are set to trigger when tire pressure falls 25% below the tire pressure printed on the tire placard (usually found in drivers door jamb)

AGENCY:� National Highway Traffic Safety Administration (NHTSA), DOT.

ACTION:� Final rule.

SUMMARY:� This final rule establishes a new Federal motor vehicle safety standard (FMVSS) requiring installation of a tire pressure monitoring system (TPMS) capable of detecting when one or more of a vehicle�s tires is significantly under-inflated. This final rule responds to a mandate in the Transportation Recall Enhancement, Accountability, and Documentation (TREAD) Act. This final rule requires installation in all new light vehicles of a TPMS capable of detecting when one or more of the vehicle�s tires, up to all four tires, is 25 percent or more below the manufacturer�s recommended inflation pressure (placard pressure) or a minimum activation pressure specified in the standard, whichever is higher.

http://www.nhtsa.gov/cars/rules/ruli...nalrule.6.html



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