Repair-It

So I'm not sure where this topic specifically belongs so I'm putting it in this part of the forum and will let Kevin re-direct as he sees fit (but since I saw a thread about snow tires in here, I figured why not).

So, here's the topic. Around Thanksgiving time when the temperature dropped and it got pretty cold for a few days, my tire pressure light came on in my 2012 (or maybe 2011 I always forgot) Maxima. I went down to a local shop and got the tire pressure quickly looked at (I don't trust the cheap tire gauge I have and might invest in getting a better one) and the guy told me that the tires were like around 30 to 32 (I forget what the lowest pressure was but I don't think it was below 30) and so he pumped up the tires to 35 and the next day as I drove to RI for Thanksgiving, the tire pressure light went off. Now, on Monday (Jan 9), the tire pressure light came back on. I'm guessing this is once again due to the temperature dropping. If I have time today, I'll go back to the garage where I went previously and have them put more air in the tires and check the pressure. However, this now has me thinking.

I realize tire pressure can drop in cold weather but during past winters with my car, I don't remember having this issue happen frequently like it was now (twice in the span of 8 weeks). Now, I'm wondering if because I don't really drive the car as much as I use to whether that's a factor into why the tire pressure is also dropping. For the most part Monday-Thursday, I'm just moving my car from one side of the street to the other (since I live in an area where it's alternate street parking- a concept that is foreign to most of you I'm sure, ). In the previous winters that I've had the car, I was driving to and from NUWC every day (which was approx. about a 3 mile commute 1 way). So I'm wondering if the driving (or lack thereof now) is part of the issue?

Although, just now I was telling this story to a friend at work who has worked as a mechanic in the past and he started to ask me questions about how my car faces the sun and if any tires would have been hidden and maybe that's what is causing some of the tires to slightly deflate to the point that the sensor in my car goes off. So, maybe he's right and that is the true culprit at hand.

Any thoughts/comments/questions? Thanks.

I got this from the owner's manual:

The low tire pressure warning light does not
automatically turn off when the tire pressure
is adjusted. After the tire is inflated to the
recommended pressure, the vehicle must be
driven at speeds above 16 MPH (25 km/h)
to activate the TPMS and turn off the low tire
pressure warning light. Use a tire pressure
gauge to check the tire pressure.

Also it looks like your cold tire pressure is 33 psi all around.

Unfortunately, it does not appear that Nissan publishes the actual pressure where the light comes on. But I'd bet it is somewhere in the 25 psi range. It would be nice to verify that just to make sure the system is operating correctly.

Tire pressure certainly does vary with temperature (both while driving and the temperature outside). Tires can also lose pressure over time. To answer your question, I don't think I'd say that not driving the car could result in pressure loss though I did have that theory for a while on my CTS-V...

What I'd want to know is that the system is operating correctly, and that I do actually have low tire pressure. Then the focus can shift away from the tire pressure monitoring system as any kind of cause or contributor.

"What I'd want to know is that the system is operating correctly, and that I do actually have low tire pressure. Then the focus can shift away from the tire pressure monitoring system as any kind of cause or contributor."

Right, but how would I go about testing the system to know that it's functioning properly? Is it something like connect it to some diagnostic computer thing? Is this something that only a Nissan dealership could do? I'd say I'd ask the dealership to really look into it the next time I bring the car in (which would probably be around a 75k inspection) but since it appears I'm moving into Manhattan come the June time frame, I'm probably going to be looking to sell the car (anyone interested here? ) in the near future so I don't think I'm going to spend the money to do the 75k inspection.

I think, to an extent, I can buy into the sunlight theory as to why the pressure might be dropping. I didn't get a chance to today but tomorrow I should be able to take it to the garage where I last took it to put air into the tires. Also note, yesterday, I was definitely driving over 25mph at times. Now, maybe I didn't sustain it long enough for the sensor to go back to normal, but I know even driving around the area, I was going faster than 16mph. But, I'll see what tomorrow has to say.

Thanks for the input!

I was hoping the manual would say the light comes on when the tire pressure is, say, 25 psi or lower. Then you could verify for yourself with a gauge whether that was true. It may display tire pressure in some menu on some screen if you look. I thought I did see that in the manual. Then at least you could see what it thinks is going on and compare to a gauge.

From fiddling around last time, something just pops up on the screen and says "low tire pressure" or "tire pressure low". I haven't been able to find somewhere that it tells me which tire it is or what a PSI level it's reading that is triggering the sensor to go off. But I'll poke around a little more later today.

Slight update. Took the car to a local garage, guy said all 4 tires were at 30 PSI and he pumped them up to 40. I kept the car running the entire time and after the guy was done putting air in the tires, the "check tire pressure" light was gone.