Appears as though I have a bad sensor. Should I have just the bad one replaced or get all four done at the same time?
Wife's car but I drive the most as she doesn't like to drive anymore.

2020 Chevy Blazer Appox 25k miles.

2020 is too soon for a tpms replacement. Did the tire suffer a blowout and was repaired? I was told they go bad around 10 years. One on my 2013 Lexus went bad in 2024 and I wished I had replaced all 4 at once since I have to go back 3 or 4 months to get the next one replaced.

On your case, if it was me, I’d just get the one replaced and consider it a bad sample. I spend $65 for a tpms replacement at discount tires.

Another vote for Discount tire. They have a gauge that determines which sensors are bad and it was around $65 each for two on my 2015 Sienna.

I commented that my 08 Ridgeline had never needed a tpms battery and he said Honda wired them direct while most used individual batteries.

My 2017 Suburban with ~135K miles had all four tpms sensors ‘fail’ over the last five or six months or so.

I knew that I was due for new rubber going into the winter, and just purchased new tires and sensors.

The non-GM sensors were $40 or $45 each.

Based on my experience, the other three on your vehicle may fail soon too.

quote:

2020 is too soon for a tpms replacement. Did the tire suffer a blowout and was repaired? I was told they go bad around 10 years.

The batteries can last anywhere from 5-10 years.

Your results may vary but my local branch of a national tire retailer tries to upsell all four (or five as in my 2012 Wrangler) with the line “If one goes bad the others are soon to follow.

Yep, they said that to me in ‘17 or ‘18 with my Wrangler at about 80k when one was bad. I declined and said “Replace the bad one only” and I’ve got 155k on it now. Did the same thing with our ‘12 Liberty just before Covid, they got the same answer at that time. Still running three of the originals there too.

We never replaced them in sets when I worked in dealerships, just the bad one(s).

I would just replace the bad one(s) were it mine.

My 2009 car has one of the originals still in it.

Interesting, I was going to post on this exact subject. If the OP doesn't mind...

2018 Subaru Outback; 33,000 miles & original tires and sensors. I drive for about 3-4 miles and the TPMS light begins flashing. After a minute, it stays on. My tires are at the right pressure (35/F and 33/R) according to my analogue Jaco tire pressure gauge (not a stick gauge). The readout in the car shows them all about 2 psi over what the gauge says. All started about a week and a half ago. The car has no reset button.

TPMS system issue?
TPMS sensor/battery issue?
Outside temperature issue (been down to 15F here at night here in NoVA).

The tire pressure is fine; I don't see any issues driving with the TPMS light on. Would rather deal with it in the spring. I will keep checking the pressure once a week. We have a warm spell on Friday and I'll see if that makes a difference.

All the tires were low in the 30-32 psi range as we have had some really cold weather here the past week, should be 36 psi.
Aired them all up this afternoon and will check them tomorrow.
On the dash 3 tires show the pressure, the 4th just shows ---.
No Discount tire place local, just a Belle Tire and some local shops.

Screw that. I can just check my tire pressure. My motorcycle has TPMS and it went out and they want over $500 to replace it for two tires. Nope, I check my tire pressure before I ride.

Seems like when the cold set in, all the TPMS's fire off. My gripe is: why the hell don't the damn manufactures add the few cents of electronics it would cost to tell the car owner which of the four tires is alarming?

^^^^^
My 2018 Sonata has a dash display. One display option shows the pressure in each of the four tires.

Not all vehicles read out tire pressures and positions, but many do. (Mine does not.) With some vehicles, the system will lose track of wheel positions if it isn't reset after a tire rotation. Still others, if they have a full-size spare, have a sensor in the spare.

All is well. I'm just $109.02 poorer to get the one sensor replaced at Belle tire.

Magically, my TPMS warning light didn't come on today. We'll see if it stays off.