Flaky tire pressure indicator

Last night when I started my car the tire pressure indicator started blinking. I stopped ASAP and checked my tires. All were well above 30 psi and within 1 psi of each other. I restarted the car and the indicator continued blinking. After a couple of minutes it was on continuously. It did the same thing this morning. The Owner’s Manual says, “Have the system checked by your Toyota dealer.” Which, of course, is a huge non-help. I suspect one of the TPMS transmitters has died but I guess it could also be on the receiving end. I plan to drop it off at the shop that installed my tires because they’re close and it’s tire-related but with this being Christmas week I may have to live with it for a while. I hope this isn’t a dealer issue because that could really take a while. In the meantime, does anyone have any other ideas?

A blinking warning light generally means a fault in the TPMS system, not a low tire pressure. Usually it’s a failing sensor, there’s not much else to go wrong with the system.

How old is the car? I usually see sensors start to fail around the 10 year mark, but I’ve seen them go as soon as 6-7 years and some have lasted 12.

If the tire pressures are all in spec, drive on until it’s convenient to have it checked out. It’s just a warning light, won’t affect anything about the way the car runs or drives.


Sorry, it’s a 2009 with 127k and change. Figure 12-13 years old so yeah, about time. I knew it wasn’t a disaster, I just want to be prepared.

Does this car have a full-size spare tire?
If so, did you check it?

My Outback has a compact spare, and–to my shame–I hadn’t checked it for a couple of years. When I was airing up my tires recently on a cold day, I finally got around to checking the compact spare–which should be at 60 psi–and I found it to be holding only 32 psi. Of course, the compact spare doesn’t have a TPMS sensor, so you can be sure that I will be checking it more often.

+1 check the spare too. Some Toyota systems have a sensor on the spare too IIRC. I’m pretty sure my 09 Camry does.

I didn’t check the spare at the time but after consulting the Owner’s Manual I realized it’s probably a failing sensor, as @asemaster mentioned, rather than a matter of low pressure. A recent CarTalk answer indicates I’m on the hook for $85 or so.

You won’t replace it now, I hope. Live with the light or put electrical tape over it until you need new tires, then replace all the sensors with the tires. That assumes the sensors are in the tires. If they are in the valve, do it any time.

1 Like

I’ll probably go ahead and have it replaced. The paranoid part of me is thinking, “What if I actually do have a low tire before I have it replaced?” I’d consider it maintenance and anyway an expense of under three figures is pretty cheap where cars are concerned. In this case probably about the same as an oil change.

If one has failed, the chances are the others might not be far behind. Our local tire place charges about $60 per sensor. Over the past year I’ve had to replace the ones in our 2008 and 2009 Outbacks.

If the sensors are all the same age, and if there is still a lot of tread left on your tires, you should probably replace all of them at the same time. And, I can tell you that I paid ~$46 each–including installation–for my sensors, a few years ago at Costco. They are undoubtedly more expensive now, but are surely still cheaper at Costco, as compared to other places.

1 Like

The shop that installed my tires said $80-100 each. Ouch. IIRC, my tires are about 2 years old with a decent amount of tread remaining but next time I may bite the bullet and have tires and sensors replaced.

You might want to investigate the merits of becoming a Costco member. In addition to a substantial saving on tires and TPMS, you would probably be amazed at how much you can save on groceries, motor oil, wiper blades, small appliances, paper goods, clothing, and electronics.

Yes, you do have to pay a membership fee, but between the lower cost for virtually everything, plus the annual rebates on your purchases, your membership fee would likely be “paid off” by the savings and rebates after just 3 or 4 months.

The shop has to remove the tire from the rim, remove the old sensor, install the new sensor, replace the tire on the rim, then balance the tire. $100 seems a fair price for all that, parts and labor. No harm done to ask if you could get a discount if you have 2 or all 4 done at the same time. Another option if you a re diy’er oriented, purchase an inexpensive tire-remover/installer machine and a bubble balancer. A lot of work involved though. Depends if you have more time than money, or more money than time.

There isn’t a CostCo in our area (although there’s one coming next year) and my wife let our Sam’s Club membership expire.

It makes me wonder. I can get a whole tire complete with installation for $150 and that’s pretty much the same amount of work. Are they giving me the tire for free? (Just kidding.)

I would think,at least in some applications, the bead would need to be broken, the tire pushed down for clearance, the sensor replaced, and the tire reinflated. No balancing required.


Update: Last night I started my car and the indicator didn’t start blinking. It didn’t stay on either. It came on for a second and then went out, like normal. I shut the engine off and started it again, and same thing. I dropped the car off on principle, along with a note, but now I’m confused. I was under the impression the battery in one of the TPMS transmitters was dead or at least low. A battery can’t be intermittently low, right? Did I hit a bump and jar a connection of some kind back into place? And if I did, why wouldn’t the indicator go out right away? The guy from the shop called about Noon and said the left front sensor had a low battery. I authorized replacing it for $97 parts and labor but it beats me why the indicator stopped acting up?

I’m at my daughter’s house and my ouija board is at home. Worse yet, my tarot deck is in my other suitcase, also at home. I’m afraid I can’t help. :wink:


Batteries use a diffusion process, and diffusion rate is controlled by temperature. So a battery could deliver enough power at one temperature, while not at another.

Sure it can. Have you never had an older car with a sketchy battery that sometimes would start and sometimes needed a jump? Also battery voltage and output changes with temperature.

TPMS is a wireless system, no connections anywhere.

Did he offer to replace the other 3 sensors as well while the car was there so you don’t have this same trouble 6 months from now?

The temperature when it started acting up and when it stopped was within a few degrees F. But something decided the battery was low and then decided it wasn’t. Maybe something to do with the rotational position of the wheel? Sorry but if I want a mystery I’ll watch Perry Mason.

No. He said the others are fine for now and I’d just as soon not spend an extra $300 right now so I’ll wait.