Page 1 of 1

Yet more TPMS weirdness

Posted: Tue Jun 06, 2017 9:19 am
by CrashTestDummy
After the car sat in the garage over the weekend, I hop in it this morning to make the slog to work. The minute I turn the key on, I get a tpms message that my RR tire was low. WTF?!?

I checked the information center and it's saying my RR tire is at 30 psi. Oh well, if it's just that low over the weekend, I can worry about finding the leak later. I roll out to the shop and pull the air hose out and put air in the not-low-looking right rear tire. After feeding it air for a bit, I go check the dash. STILL 30 psi!! WTF?!? I turn off the car, then start the car again, thinking that it has to re-read on startup. Nope.

Soo, I go get a tire gauge and check that tire. 61 psi!! I drop the pressure back to 50, just in case there is a leak, and then go check the RF tire, to make sure it's not an issue with my tire gauge. It reads within 1 psi of what the dash displays for that tire.

So now I'm wondering what's up with the TPS. On the way to work, the pressure in that tire went up to 32 psi. So it's at least responding, but still, to me, at least, still reading wildly-low.

Is this how these things die? Just when I was starting to trust the things, I'm now wondering if I really do need to carry a tire gauge with me, just in case. This is the first issue I've had with the system. The last low pressure notification was indeed a low tire.

Is it possible that one of the other tires are really low, like one of the ones on the left side? What do I do now?

Re: Yet more TPMS weirdness

Posted: Tue Jun 06, 2017 9:35 am
by Navy Lifer
Just as a matter of curiosity, what pressures are you running?

It sounds to me that you're probably looking at a faulty sensor--reaching end-point of battery life.

TPMS is a government-mandated system--unfortunately, many choose to let it "die" because of the expense, since the sensors eventually reach a non-functional status, and people are OK with having the light on the dash rather than spending $100+ for new sensors.

Nice to have the option--tire pressure gauges are cheap by comparison.

Re: Yet more TPMS weirdness

Posted: Tue Jun 06, 2017 11:30 am
by elc32955
I'd check 'em all post-quick to be on the safe side. The way I understand the system works, if your tires were rotated and a re-learn wasn't done on all 4 to reflect new positions, you can have tires in different positions then what the monitor reflects. My car had this happen once, my LR was going low and it alarmed, the tire shown on the monitor was actually the RF if I remember correctly.

I always keep a tire gauge in my trunk box with a long stem, industrial truck tire gauge that reads 0 to 160 PSI - got them cheap off EBAY.

Of course that still doesn't explain the faulty pressure readout, one of your factory TPMS is probably going south. I replaced all 4 of mine with aftermarkets from the local Goodyear dealer when they started failing, I'm very fastidious about making sure all the warning lights are off. It'd bug the hell out of me driving with the monitor in alarm.

Eric

Re: Yet more TPMS weirdness

Posted: Tue Jun 06, 2017 12:02 pm
by s/c'd cav
they do not read instantly , it only checks them every so often , if they transmitted a signal 24/7 the battery in them wouldnt last long

as they are its best around 5yrs to replace them , some do last longer , so barely last a year

Re: Yet more TPMS weirdness

Posted: Tue Jun 06, 2017 12:26 pm
by CrashTestDummy
I have a stack of pressure gauges, and I can pitch one in the car, but was hoping I could live without one. I guess I'll have to pick one up on the way home this afternoon to make sure the POs haven't rotated tires and not completed a re-learn.

I, too hate seeing the warning lights, and do my best to keep them from coming on. I guess one of my days off this weekend will be troubleshooting that TPS issue.

I usually try to run max cold pressure as indicated on the tire. That's where you'll get the best MPGs, and less sidewall squirm in the corners. ;)

Re: Yet more TPMS weirdness

Posted: Tue Jun 06, 2017 12:27 pm
by CrashTestDummy
s/c'd cav wrote:they do not read instantly , it only checks them every so often , if they transmitted a signal 24/7 the battery in them wouldnt last long

as they are its best around 5yrs to replace them , some do last longer , so barely last a year
Well, IFF they're OEM sensors, they're now about 5 years old. I'm sure we're not running the original tires, but have zero clue about the sensors.

Re: Yet more TPMS weirdness

Posted: Wed Jun 07, 2017 8:36 am
by CrashTestDummy
elc32955 wrote:I'd check 'em all post-quick to be on the safe side. The way I understand the system works, if your tires were rotated and a re-learn wasn't done on all 4 to reflect new positions, you can have tires in different positions then what the monitor reflects. My car had this happen once, my LR was going low and it alarmed, the tire shown on the monitor was actually the RF if I remember correctly.
<SNIP>

Eric
^^ This! I stopped at a 'quickie-mart' on the way home and purchased one of the best tire gauges Chinese prison labor can make (well the ONLY tire gauge, which made it the best), and checked the other tires. The front left read 30-40 psi, I took the average of 3 reads. :| So I aired that tire up so that the gauge regularly-read over 40 psi. The TPS readout displayed 42 psi, so I figured I was good to get home. I topped everything off when I got home.

Thinking about it some more, the car did seem to have a bit of a pull to the left when braking and driving slow, so that should have been a hint. I didn't get it, though.

I'll monitor that 'RR' tire pressure and see what happens with it. I've about gotten my money's worth out of these tires (they were on the car when we bought it), so if it continues to loose air, I'll probably need to replace the tires as opposed to getting this one repaired.

In the meantime, I'll start shopping for tires.

Re: Yet more TPMS weirdness

Posted: Thu Jun 08, 2017 9:02 am
by Navy Lifer
Generic article--may be a few nuggets of valuable info:

http://www.chevyhardcore.com/news/quick ... -toyo-tire" onclick="window.open(this.href);return false;