Low Tire Pressure Indicator Problems

[PSU4Runner]

I own a 2005 SR5 V8 4Runner. Overall, I am very happy with the vehicle, but I have had a hell of a time with the low tire pressure indicator. Every time the temperature drops into the 40's, the indicator light turns on. I have checked the pressure and everything checks out. I have taken it to the dealership to have the tires inspected, no leaks or holes in any of the tires, the merely explained that the changes in air temperature and pressure will cause the sensor to show low pressure.

My question is if this is the case, then what use is this indicator other than to annoy me as I drive? The dealership doesn't feel that the sensor is faulty, according to their service techs, this happens all the time. Is there a way to reset or turn off that indicator lamp manually?

I would like to turn the light off, check the pressure and then see what temperature triggers this problem so it can be examined. Any help that you can provide me is greatly appreciated.

 

[Bobby]

Welcome to the forums!!!

Drop your spare tire and fill it up to 36-38psi.

 

[PSU4Runner]

Welcome to the forums!!!

Drop your spare tire and fill it up to 36-38psi. [/QUOTE

Thanks for the advice. I have checked the spare, and it is inflated to 38psi, so I don't believe that is the problem (the dealership did this the last time I went in for service).

I have it down to either a faulty sensor or a very sensitive sensor or system. Since the dealership says that the sensor's aren't faulty, it seems apparent that temperature changes seem to be triggering this problem. If I could turn off the light and do a few tests on what temperatures cause this problem, I would have a better amount of information to give the dealership so they can replace or repair the problem.

 

[fishepa]

Mine does the same thing.

 

[sharp4runr]

What PSI do you have the 4 tires set to then? I have mine set to 35psi and the light doesn't come on when it goes below 40.

 

[alpha]

My dad's did that. Went off and on for a couple days, stayed on for a day, checked the tire pressure, tires were at 35, and spare was at 40. hasn't come on since.. dunno.. the outside temp has been about the same when it went off and the past couple weeks..

 

[PSU4Runner]

What PSI do you have the 4 tires set to then? I have mine set to 35psi and the light doesn't come on when it goes below 40.

All of my four tires are at 35psi, with the spare at 38.

It's a bit warmer here today in Tennessee, creeping up into the high 50's, no change in the pressures of the tires, yet the sensor came on again this morning.

 

[sharp4runr]

Now when the TPMS light comes on, is it a constant light or is it blinking? If it is blinking then there is something wrong with the system or sensors.

 

[PSU4Runner]

Now when the TPMS light comes on, is it a constant light or is it blinking? If it is blinking then there is something wrong with the system or sensors.

It's constantly on.

 

[JB.]

I own a 2005 SR5 V8 4Runner. Overall, I am very happy with the vehicle, but I have had a hell of a time with the low tire pressure indicator. Every time the temperature drops into the 40's, the indicator light turns on. I have checked the pressure and everything checks out. I have taken it to the dealership to have the tires inspected, no leaks or holes in any of the tires, the merely explained that the changes in air temperature and pressure will cause the sensor to show low pressure.

My question is if this is the case, then what use is this indicator other than to annoy me as I drive? The dealership doesn't feel that the sensor is faulty, according to their service techs, this happens all the time. Is there a way to reset or turn off that indicator lamp manually?

I would like to turn the light off, check the pressure and then see what temperature triggers this problem so it can be examined. Any help that you can provide me is greatly appreciated.

My sensors trigger approximatlely when any tire drops below 30psi.
If your tires were at 32psi in the garage at 65 degrees, then they would drop below 30psi at 40 degress and trigger a sensor (1psi for every 10 degree temp drop). So you'd want the tires at 32psi or higher at the lowest temperatures likely to be encountered for the season.

Since you seem to have ruled out the spare and the dealer says no faulty sensors, I'd get a hold of a couple more tire guages for comparison. Maybe the 35psi you think you have is actually much lower. Make sure you check the tires when they're coldest.

 

[PSU4Runner]

Re: Re: Low Tire Pressure Indicator Problems

My sensors trigger approximatlely when any tire drops below 30psi.
If your tires were at 32psi in the garage at 65 degrees, then they would drop below 30psi at 40 degress and trigger a sensor (1psi for every 10 degree temp drop). So you'd want the tires at 32psi or higher at the lowest temperatures likely to be encountered for the season.

Since you seem to have ruled out the spare and the dealer says no faulty sensors, I'd get a hold of a couple more tire guages for comparison. Maybe the 35psi you think you have is actually much lower. Make sure you check the tires when they're coldest. [/QUOTE

That's a good idea, I hadn't considered a faulty gauge. It may be unlikely, but I want to rule everything out.

Thanks!

 

[Dire Wolf]

The dealer set it up for the spare pressure warning to come on at a certain temp.
Just fill the spare with a little air.

 

[alpha]

The dealer set it up for the spare pressure warning to come on at a certain temp.
Just fill the spare with a little air.

really? I think that's the first i've heard of that..

My dad's did it again last night. I dunno, it got colder than usual. But I dunno, it went away after driving for a bit. The tire pressure is fine, for all 5 tires. 35 psi for the four, and 40 psi for the spare.

The reason it seems weird to me is that mine doesn't do it. And at school, where I've had mine, we had single digits and teens for a good 3 weeks before I came home for break..

 

[Spider5]

What strikes me as funny is that of the hundreds of post dedicated to this tire pressure system there is not one time I've read that someone was glad to have it. If I had these types of problems with the system I would rip out the sensors and break the indicator light.

my 2 cents

 

[KyleKai]

Mine came on about a year after I bought the car new. I checked the tires and they were all around 26 PSI (guess the dealer forgot to check them when I last brought it in). I inflated them to 32 PSI, and the light went off. So count me as one person glad to have the gauge.

One complaint tho. The light went on during a long trip, and after buying a new gauge (to be sure it wasn't a faulty gauge), I called the dealer who said to check the spare. I did, it was low, I inflated it, and the light went off. I only wish this was mentioned in the owner's manual; would have saved me some worry.

 

[Kmvreter]

What strikes me as funny is that of the hundreds of post dedicated to this tire pressure system there is not one time I've read that someone was glad to have it.

I'm happy to have it. The light came on once because of a slow leak. Got the the puncture repaired (from a piece of shrapnel still stuck in the tread.) Saved running on a flat and ruining a tire.

 

[kgray01]

Mine does the same thing everytime it gets in the low 30's. Usually boosting the tire pressure in all of the tires (including spare) to about 35psi cures the problem. I love the system. My wife would drive with 10psi in all the tires as long as it got her to where she was going.

 

[neowig]

Mine does the same thing everytime it gets in the low 30's. Usually boosting the tire pressure in all of the tires (including spare) to about 35psi cures the problem. I love the system. My wife would drive with 10psi in all the tires as long as it got her to where she was going.

it's been in 50's and 60's in denver in the past few weeks. suddenly, the temp dropped to low 10's. but the tire pressure warning light never came on despite of this temp. change. i park my car outside on the street and start it in the cold morning everyday...

guess what i'm saying is that, temperature variation shouldn't govern how the pressure warning system works. if the light comes on, as the original stated, in the cold morning, i'd get it serviced ASAP...

 

[sharp4runr]

guess what i'm saying is that, temperature variation shouldn't govern how the pressure warning system works. if the light comes on, as the original stated, in the cold morning, i'd get it serviced ASAP...

Tire pressure changes with the temperature outside. Tire pressure decreases by about 1 pound per square inch for every 10-degree drop in outside air temperature. Feel free to waste your time and efforts taking this in to the dealership. They'll just smirk and laugh at you behind your back. :

 

[neowig]

Tire pressure changes with the temperature outside. Tire pressure decreases by about 1 pound per square inch for every 10-degree drop in outside air temperature. Feel free to waste your time and efforts taking this in to the dealership. They'll just smirk and laugh at you behind your back. :

yes, you are right that tire pressure changes with the temperature outside. we all learned that in elementary school and you don't have to brag about that

i read it somewhere in this forum, though, that the tire pressure sensor detects the difference between the tires and gives out warning.

if i set my tire to 30psi at temperature 30F, the tire pressure can vary from 27 to 33 psi, if temperature variation is 60 degrees (from 0 to 60F). I don't think Toyota designed the sensor to detect this temperature variation cuz after all, it's called pressure warning system, not cold temperature warning system.

what makes more sense to me is that, if ONE OF THE TIRES reports lower pressure compare to the others, then it would make sense to report it by turning the warning light on.

of course, i could be wrong. please post if you have the definate knowledge on how this pressure sensor works.