Low tire pressure light weirdness

2008 DCLB 4.0 prerunner 173k.
Today while driving down the highway my low tire pressure light started flashing for a few minutes then came on solid. I pulled off and checked tire pressures and my gauge said all 4 were right at 34psi.
I didn't get manuals with the truck when I bought it about 2.5 years ago so I can't look it up. After I turned the truck back on the warning light was off and has stayed off. Is this telling me a pressure monitor battery is going bad? It didn't seem like the pressures were low. What else could it be?

Thanks!

 

My 2006 is still running the original TPMS. When I have it below 30F it has same behavior. I believe it is battery/batteries. I did same check pressure, check spare, reset TPMS. I'm going to replace them all when I'm due for tires. Good luck. Please share the result.

 

If it needs new ones get these, great price and authentic.

Look at this on eBay
https://www.ebay.com/ulk/itm/223647514483

 

Don't our spares have the sensors too? I have to air up my spare every few years and the light goes off.

 

Yes yours might

 

Yep, that was 1 of my bargaining chips when I bought my '06 Taco from a car lot. The light was on and the tires were visibly low. I used their air to air up the 4 tires. The light was still on. "There's something wrong with the TPMS system. That's gonna cost money to fix." Found out a few days later that the spare has a sensor. Yep, spare was low. Aired it up and the light went out.

 

The TPMS sensor is only in the spare for a few model years. My 07 has one in the spare. But about 8-10 years is about as long as most batteries last. My sensors are still working in my 07 Tacoma, but the batteries died in the 09 Honda about a year ago. I'd advise buying some before you need new tires. Any tire store will install them free when you get tires mounted. If you try to replace them any other time it will cost you $10-$20 per tire to replace them.

 

Thanks folks. It didn't dawn on me that the spare might have a TPMS and I didn't check it
Will try to do that this weekend. BTW I drove about 140 miles after I checked the 4 tires, and it never came back on.