Service tire monitor system light

I have a 2009 Buick Enclave with 69000 miles and app 9000 miles on this set of tires. The above message has been coming on after I drive 50-100 miles. Today the message came on, flashed a while and then went back to being constantly on. When I checked my tire pressure it showed a blank for the left front tire and 38/39 for all other tires. The recommended PSI (?) is 35. What does this service message mean and is it something that needs attention right away? If so, is this normally an expensive/inexpensive repair. Also, please, is it OK for my PSI to be 38/39 in warm weather driving? Thanks for your help.

If it tells you which tire, it will be expensive for direct sensor replacement from a dealer but a third to half from a shop. . We have had this discussion before but check to see if your state mandates it for inspection. Then it becomes, your choice to wait till you can afford it. If it’s an indirect sensor using the abs, check your manual. It may be nothing more then making sure all pressures are the same and perhaps lower like 32 on the door jam, and waiting a few days. If it is an indirect sensor, maybe your tires are worn unequally and that could be setting it off. Have that all check out at a tire shop.

The light is most likely on necause the pressure sensor in the left front tire has failed or lost sync. A tire shop can scan the sensor and tell you which has happened and how to fix it. A sync issue should be cheap and easy. A failed sensor needs to be replaced, and the tire will need to be dismounted to do that.

The recommended PSI on my 2013 Chevrolet Equinox is also 35 PSI cold. Once the tires have warmed up from driving it’s normal to see a 2-3 psi increase. Tire pressure will increase/decrease ~1 psi for every 10 degree change in temp.

I suggest using a tire pressure gauge to check each tire, this will verify if the TPMS sensor in the valve stem is working. I prefer a good quality dial-type gauge such as:

Ed B.

Some will disagree but my contention is that if you have a quality tire pressure gauge…you don’t need TPMS to begin with. I see plenty of TPMS warning lights in vehicles…but no low tires. I think it’s totally ridiculous to have a low tire pressure warning system that only warns you of bad TPMS sensors.

“…you don’t need TPMS to begin with”

Yes, yes you do. The federal government says you need to have an active sensor inside every tire/wheel assembly on every car sold beginning with 2007 model year. (sarcasm)

But back to the original post…you have a bad tire pressure sensor. Your display says it’s the left front but that only applies if the wheels have been programmed to the proper position. The car comes out of the factory reading the tires in the proper position, but the positions need to be relearned whenever the tires are rotated or replaced. For example, your left front tire may be rotated to the left rear, but unless the system is “relearned”, the car still thinks that tire is on the left front.

This shouldn’t be too expensive to fix, maybe a little over a hundred bucks. But remember, these sensors are battery powered and you have 3 more.

If your tires are supposed to be at 35 PSI, that’s to be measured outdoors when the tires are cold (not driven upon for a few hours) in the early morning, which is the coldest part of the day. If your car is in a garage, then you can adjust for that by adding 1 PSI for each ten degrees that the garage is warmer than the outside temperature. When you drive on the tires and when the temperature goes up later in the day, the pressure will go up, but that’s okay. If you’re seeing 38 or 39 PSI after driving, your cold pressure is probably pretty close to 35 PSI.

TPMS sensors aren’t always that accurate. As mentioned above, it’s best to still check your tires manually. I also vote for a dial-type gauge; I’m partial to Accu-Gage ones myself.

missileman wrote:
Some will disagree but my contention is that if you have a quality tire pressure gauge…you don’t need TPMS to begin with.

Yes, I will disagree. I check my tire pressures as much as anyone here, but I’ve had at least two occasions where TPMS has alerted me to picking up a nail or screw. I don’t remember the details now, of course, but I could easily have driven on a low tire for another week or so until my next manual check.

“Yes, I will disagree. I check my tire pressures as much as anyone here, but I’ve had at least two occasions where TPMS has alerted me to picking up a nail or screw. I don’t remember the details now, of course, but I could easily have driven on a low tire for another week or so until my next manual check.”

Call me old-fashioned, but I still look at all of my tires before I get in the car each time and check the cold pressure once per week. And yes, I know that a “visual” look at a radial tire can be very deceptive. But it’s pretty easy to spot one on its way to flat. I’ve had my share of basic nail/screw punctures and have not yet been changing a tire on the side of the road from one of those. That’s not to say I haven’t had to change a tire on the side of the road. Some punctures/failures act quite immediately, in which case TPMS isn’t going to help much anyway. And…I have also had the not-so-slow leak, but not completely flat tire while driving, and sorry, but unless you’re brain dead it’s pretty obvious that the car handles differently. Some would ignore such things without TPMS. I don’t.

I am truly disinterested in these systems. Others are. That’s fine. Have at it.

Just more babysitting that the buying public is demanding more and more because they have no intention of actually participating in their vehicle’s functions.
– On another post about why there’s not many cheap plain vehicles, I answered abous this very type of subject.
As much as I personally want a plain jane vehicle, the general public masses want all the systems on the vehicle to attend to themselves effort free on the part of the user.
And TIRES is just another one of those. So moch so that the government has become so involved in the babysitting as to now require it !

+1. I haul scrap as one of my many jobs, meaning I pick up my fair share of metal in my tires. I have yet to have a nail puncture result in an unsafe condition…I’ve always caught it WAY before it got to that point (via “preflight walk-around”) and fixed it with a rope plug (there’s the bait, in case anyone wants to bite…)

Thanks everybody for the great answers. I normally depend on my monitor system to check tire pressure. I am glad to know that these readings are not always accurate. I will start having my tires checked manually regularly.
Asemaster, I would like to know more about the relearning thing after my tires are rotated. Is there something I, or my tire shop, need to do for this to happen?As for my current problem I will first go to the tire shop where I purchased my tires to see if they can help. If not, I guess I will be visiting the Buick folks. Thanks again.

MM writes …

I think it’s totally ridiculous to have a low tire pressure warning system that only warns you of bad TPMS sensors.

If you think about it, about all those tire pressure systems do is tell you the system isn’t working. Yes, you are right. I think that would be a great joke about the perils of technology for one of those late night tv comedy show monologues … It’s a great observation … lol …

There’s a relearn procedure that you or your tire shop can do. I don’t recall what your specific instrument panel looks like, but there should be a menu item somewhere for tire relearn. It involves a specific routine of starting at the left front, inflating or deflating the tire until the horn sounds, and then following to the next wheel indicated on the panel until they are all done.

Someone once complained to me that the dealer wanted to charge $40 for a tire rotation when the car was already in for an oil change. That’s because of the relearn procedure. I can tell you that many shops don’t do the relearn, as it’s not required on many cars and some cars require specific equipment to do it. My point was that just because your instrument panel says LF tire low doesn’t necessarily mean that it’s actually the LF tire.

Yep, me too. I like them. I was on a 800 mile trip when the alarm went off. I had picked up a 2 inch screw. There was no handling issue so knowing I had a problem allowed me to find the nearest tire shop for a repair without having to change a tire on the side of the road or ruining a tire. I check my tires too but the TPMS allows me to monitor it on the road whenever I want.

Where are my tweels? another costly system to fail-Kevin

I think most of you are missing the point. As a regular poster on this board I know many of you are diligent about maintenance and knowledgeable about cars. Most drivers on the road do not meet either of these criteria. It is for those people that many safety features are developed. How many people died as a result of tire failures caused by flats or low tire pressure that people like us would have caught earlier but other people did not? My personal experience with TPMS is that it twice has caught tire pressure discrepancies that I would not have noticed until they were more exaggerated and I have not yet had a sensor fail.

On another note, my 2014 Mazda6 does not have TPMS sensors inside the tire. The TPMS system appears to be run from sensors in the hub. I only discovered this when I went to buy snow tires and found that I did not need to buy hundreds of dollars of TPMS sensors in my new wheels. I wonder how they pulled that one off since I thought the regulation required sensors in the wheels?

@GeorgeSanJose … thanks for your comment. I was going to lambast the CEL systems as well but they…unlike TPMS…actually get something right every now and again. I still think the CEL system should be called PGFRS or Profit Generator For Repair Shops because that’s really it’s function if you think about it.

I think rightfully so, cars are mandated to have tire pressure warning devises. But, rightfully so also, in many states, they are not required to be there for state inspection. At least around here, it would be a real big extra cost if states would also like to see people have snow tires mounted on separate rims. To me, it’s weighing two important safety considerations and I am glad I have that option. The extra two hundred plus dollars could be a big game changer.

Btw, I will also continue to check my tires. Mainly because these devises are obviously not fool proof and just because they often fail to agree with correct pressures, they could some times fail to indicate improper ones as well. Besides, even with the warning, I still have to get off my fat asteroid and do something about it. Might as well be checking it so my wife doesn’t t think I’m a worthless piece of ("/$@&) and I have “some” value.

You’re old fashion ! You did asked to be called that…