Toyota Repair: computer tire guage on dashboard, toyota tacoma prerunner, tire pressure monitoring system

Question
We live in Savannah Georgia and have a Toyota Tacoma prerunner sport 2006. Problem the tire on the warning dash comes up and stays on when the temperature gets lower than freezing. The first time we were out of state and AAA checked all the tires and said they were all low. He added air to all and warning went off. Dealer said that couldn't be next time we brought it to them with the same complaint and they found no tire problems and somehow got the warning light off. I asked how to solve the problem. They said there was no way that every time we got lower than freezing that I with my bronchial asthma and my heart condition or my husband who is disabled will have to crawl under all 5 tires and check the air. Good thing we don't live in Chicago.  Help!They would not remove it or make it less sensitive.    Judy

Answer
Welcome to 2008 two years early! All new vehicles for sale in the US (from 2008 onwards) are required to use a monitoring system of some kind or another for tire pressure.
If the system triggers. The tire pressure is lower than the set value it's suppose to trigger at & the pressure should be checked regardless. That's why they've been mandated.
Sweetheart I don't have anything relative I can tell you. The lower the temperature, the lower the pressure & the tires should still be checked. No different than it was 70 years ago. The tires are under-inflated becuase of the cold weather & should be re-inflated for the winter. All vehicles are subject to that with, or without a monitoring system.

At any rate. You should have a reset switch under the dash for the tire pressure monitoring system. (T-PMS Yes... There is a joke in there!) All things depending, some of the newer ones have another circuit where you can change the pressure they are activated at also.

Like most owners that have never had an original equipment, or an aftermarket tire pressure monitoring system. You're going to be quite surprized at how often your tires are actually under-inflated! The NTHSB is probably correct when they estimate at any given time 25% of the vehicles in the US have tires atleast 25% too low.
Put 38-40psi in the spare tire & 38psi in the others. Just don't drive fast if you use the spare. You'll get alittle better economy, alittle better wear & sacrafice little in comfort. And... You'll go longer between having to air the tires up.
The good news is that the system at this point works fairly well & problem free when not banged up. Toyota has been using different versions of it for about 10 years on various vehicles so... The "teething" problems alot of manufacuters are about to have are already sorted out.
Just make sure anytime you have tires changed that the person doing the work is very careful with the valve stems. That's where the wirless pressure monitor is located. The cost will come down, but at this second, they're worth $350-400usd a pop from low avalibility.

Sorry as I can be, unless it's broken. This is just part of owning any car, modern or not. The differance is that now - by law - the car is required to tell you when the tires are atleast 25% low. (In all honesty, they should set it to 10% low, but that's another discussion!)
You will not get the system removed legally. It can be set to activate at a different pressure tho. I'm not sure, but I think it activates around 24-27psi. The factory specification is 32psi. So anytime the monitor comes on... You're really getting low. Like I said. Put 38psi in the 4 main tires & 38-40psi in the spare. In all honesty, if it were mine. I'd do that & get the system reset to activate at 29psi. That way you get longer between activations, but you also get it activated alot cloer to the specified tire pressure. You get warned before there is even a hint at a handling, or wear problem from low pressure.

Just a thought. :) The owners manual should cover resetting the system, but even if you reset it. If the pressure is low, it's still too low!

Just think of it as regardless of the system being isntalled, or not. You should still be checking all of that stuff on a weekly basis. I won't say you shouldn't check them as such now. (You should - becaue while the system reads exactly the pressure in the tire & you're complaining abot over-sensativity, they're actually set not sensative enough.) But if you bump the pressure up & have them set the trigger pressure higher. Assuming the system works... Anytime it turns on, put the 38psi in all the tires & wait until it tell you again. Assuming it works.

So think of it as having to get down & check them even less than normal. :) Cheers!

















DO NOT rely on the system in it's stock pressure rating to tell you when the tires are too low. The pressure it's set to trigger at corrisponds to almost nearing catostrophically too low of a rating.

When not reprogrammed it is designed to tell you when something signifigant & concerning has happened. Not as a guide to when you should air the tires. (So if you don't get it reprogrammed to be more sensative. Yall should still be checking the pressures on the weekly basis that has been the standard since cars used inflateable rubber wheels.)