PAULY_LONG

I need to vent ... I hate the TPMS system in my G - and sounds like I'm not alone, based on the searches I've done.

My light came on solid on Monday, after a 20 degree drop in temp (fall is here). Checked pressures, read 30 on all four wheels. I didn't think that would be low enough to trigger the light, but I wanted to top all the wheels up to 33 so I didn't look stupid when I brought it into the dealer.

I learned today how hard it is to find a free air hose at a gas station that actually works. Finally had to borrow my neighbor's air compressor. Also, learned that pressure gauges are highly variable. I had four different gauges, all gave different readings - I split the difference between the two that were closest in readings. The spread was 6 PSI between the highest and lowest.

Drove the car for 20 miles on the freeway, hit a couple bumps, and finally got the f***ing light to go out.

So questions:
1. Does anyone know at what pressure the TPMS system will alert?
2. Any recommendations on a reliable, accurate pressure gauge?
3. Next door neighbor says he had a little magnetic thingy that he ran around his valve stems on his Jeep Cherokee when he needed to reset the TPMS sensors. Has anyone here had any experience with that?
4. I'm still thinking I have a sensor issue rather than a pressure issue, but now that the light is out, the stealership is just gonna tell me they can't reproduce it. Based on what I've described, any consensus on whether it sounds like a sensor issue?

Thanks and happy TPMS.

-----

2010 G37x, 14K miles

Buster09G37S

Had the very same issue this week on my 09 G37S with 47K mi here in ATL--temps were down ~20 degrees. I have a digital gauge that historically is very accurate. All 4 wheels read 30psi and the light was on. After the sun came up and some spirited hwy driving, I managed to get the light out, stopped and checked warm tire pressures and all were 35psi. Running a test, I dropped the front tires to 30 and sure enough, light was back on. So, in my test, the "trigger" point is 30psi or below. Hardly a risky pressure, but good to know. Reinflated to 35 psi in 65 degree weather with warm tires. Next morning after a 47 degree night (purposely left outside), pressure dropped to 31 each...no light. Good to go.

WILLDOGS

I just went thru this as the temps are getting cooler.

I had all 4 corners at 32PSI - Apparently not good enough.

I thought the system had a fault until i went to get my oil changed and the tech told me he set all 4 corners to 35 PSI and that my light should go out once I start driving.

i didn't believe him, but lo and behold the light went out and stayed off since then.

I guess the TPMS system doesn't like being under 35 PSI for some reason.

Good luck

Tazicon

iTrader: (1)

This happens on all cars not just G's......................Any newer car will do thius when the temps drop. Happens every fall/winter/spring when I head out of town into the mountains of Utah.


Couple of items that are great to have. Tsunami aircompressor from Pep Boys. Cost around $60.00 will inflat G tires in no time, clips on the battery. Screw free air. A home air compressor, I really don't think anyone should be with out one. I understand not every can as they dont have a garage, thats where the Tsunami comes in. I use mine on my Jeep to air up after trail runs. I air up 4 33" tires from 8# to around 35# on a regular bases. These are just good little air compressors for the money. Get the red unit. It even has a muffler to lower the sound, coiled air hose etc.


See link
MasterFlow Tsunami MF-1050 12 Volt Portable Hi Volume Air Compressor | Product Details | Pep Boys

tejasg37x

Why do you hate the TPMS for doing what it is supposed to do?

There is a thing called physics that applies to temperatures and pressures...thus all tpms will have this issue when the temperature drops quite a bit.
Mine did it this weekend when the temperatures fell in Texas...so did my wife's Toyota.

Just find yourself a good gauge and keep it in your car.

PAULY_LONG

Temps dropped again last week, and the light came back on. So I took it in to the dealer on Friday and they confirmed that the system is working normally.

I learned that even though the sticker on the door reads 33 psi, the TPMS will alert at 32 psi or lower. It will also alert if there is a variance of more than 2 psi between tires. That's what they told me anyway.

Given that we are at 4600 ft in elevation, and the temps will continue to drop, they filled me up to 38 to compensate for the altitude and in anticipation of the coming colder weather. They were also nice enough to evacuate my tires and refill with nitrogen at no charge.

Appreciate the recommendations on the small air compressor, and I agree that I need to just invest in one. Doing the gas station thing sucks @$$ and I don't want to do that again.

IsDatiT

iTrader: (6)

Since you are so picky about a couple PSI...
Just Replace the air with Nitrogen. Problem Solved.

sniper27

iTrader: (2)

i've had my psi down to 29 and the light still didn't come on.

also, most gas stations will turn the air on if you just ask them.

Ibanez540r

iTrader: (1)

ashmostro

iTrader: (3)

Wait... how are these TPMS "woes?"

Seems to me the TPMS alerted you to a low pressure situation, and then after you resolved it, alerted you that your pressures are now fine.

What is it you're complaining about then? I'm confused.

rpm&my_G35

This is my second, 2nd gen G. The TPMS light has always come on when the weather cools a fair amount. Mine came on a few days ago. Put the tire pressure gauge on the front left tire and read 27psi. This is about the same pressure the light would come on with my 07G as well.
Topped up all four upto 35lbs and the light went off in about 500m of driving.
I don't see this as an issue but more as a good reminder to check and inspect your tires. Not just for pressure but for unusual wear and/or damage.

tejasg37x

FYI-

For about every 10 degrees of temp drop, you will lose about 1 psi

Rochester

iTrader: (9)

Air is 78% Nitrogen already. Just saying. Not a racecar.

Winner.

owslystnly

I've not had a problem with my TPMS, except when I got a screw in a tire and it was leaking air. So I guess that wasn't a problem with the TPMS.....

ashmostro

iTrader: (3)

It sucks when technology works as advertised, doesn't it?