low tire pressure

my tire pressure light goes on when it drops below 30 degrees outside. Usually I'll put air in my tires and it will go off.
But, this week I put air in all four of my tires 40-44 psi, drove for two days, and it hasn't gone out yet, so I check the pressures again they were fine, then I tried to reset the gauge, it did it's three slow blinks, but did not go out.
When i turn the key it just lights up, it does not blink at all.
Could there be dirt or crud on one of the sensors??
Maybe it's frozen, Or could it be the spare??
I don't want to go to the dealer for this and have them charge me up the yazoo to clean my rims.
How about if I pull the fuse to see if it resets??
Any suggestions
Thanks
Barry

 

Your spare tire has a sensor to, check it. It's probably low

 

what year is your truck?

 

It's a 2008 double cab, tomorrow I will lower the spare to check it, but after that if that is not the problem, what then?? Which way should I go??

 

One of the sensors is bad if that doesnt work on the spare

 

I thought that maybe it would warm up, but it's been three days of driving and 50 degrees out, will check the spare tomorrow on my day off, thanks

 

Yeah, it was the spare, put some air in and all set!
Thanks for the help
Barry

 

I know this is an older thread but i have the same issue. I just bought new wheels and wanted to switch my tpms into the new tires. My problem is that my tpms light is on. All tires are filled including my spare and I reset switch. I have to "cross this bridge" now. How do I figure out which sensor is bad?

 

If it blinks for one minute then stays solid you probably have a bad sensor. Mine did that when I got new tires. The shop broke one of them. I just disabled the system.

 

Yeah if you aired all your tires correctly including the spare, chances are one of your sensors is bad. What did you air the tires up to?

 

They are around 35 psi. I didn't measure the psi in the spare but i had the pump on there for a while. The spare was a little tough to get at but i will try to measure for sure tomorrow. Stupid question, does the spare mount in one particular direction. I noticed some wear from it rubbing on the undercarriage. Any solution?

 

I really could care less if I have the TPMS. Imo, they are worthless since they do not tell you which tire is going low. Soccer mom bs, just like the useless abs system.
I air down and fill up my tires multiple time per week so i keep a good eye on pressure regardless of the light on my dash.

How did you disable the light/system?

 

I checked the spare tire last night and it was low. It was a bit awkward when I "tried" filling it up the other night. I guess I will try harder tonight and see if the light goes off. Does my 08 even have a Tpms in the spare? I thought I read somewhere that the some 2nd gens don't have them.
If I install the tpms's into my new wheels, do I need the dealer to pressurize and reset or just find a tire guy with a magic wand??

 

08's do have spare sensors.
If you MOVE the current TPMS sensors into new wheels-You can inflate and reset them. If you get new sensors, you'll need someone with a tool to program the new sensors into the computer before resetting the pressure.

 

The new tire is at 65psi and the spare at 35psi at full load. Will the lower psi in the spare set off the light? What do ya do?

 

65psi?!

 

The psi needs to be 25% of each other...a difference of around 8psi will trigger the sensor. The spare can be stored stem down for easier access. Why would you have a tire at 65psi? Do the chalk test and get them all close to the same...with the weight of the Tacoma you should end up somewhere around 30-36psi.

http://www.toyotatpms.com/tpms_toyota.htm

 

I was told my 2011 have a sensor in the spare when I asked about it from the dealer.

 

Toyota quit putting them in the spare around 2009.

 

I was going to put on tires that took 65 pounds/square inch(psi) at Max Load Capacity. I am wrong, I just checked, most 285 Nittos can take 80PSI. Sounds like a lot to me too. Anyone have the Nitto TG's in 285's?

My spare would be my regular stock 265/70/16 which requires 35psi at full load capacity.

Even if I bring the Spare to 45 and drop the tires to 65 there is a 20lb difference. 25% of 65 is 16.25lbs.