Kia k5 low PSI warning

Hey there. I have a Kia k5 that’s had a low PSI warning for a week or so. The thing is, I don’t think it’s because it’s low. Three of my tires will be around 28 or 29 and go up to 31 as it gets warmer. The back passenger tire is usually 2 or 3 PSI below the others, but it also goes up as it gets warmer. Could the warning light come on just because of the difference of PSI and not because the tire is too low? The warning is only for the one tire, but the other tries have started out low at what the problem tire ends up at, but with no warning light. Hope this makes sense.

Set the tire pressure at what the door plaque says before your drive the vehicle . You did not say what year your Kia is but the monitors in your tires only last 7 to 10 years before they need replaced.

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It’s a 2021. Only had it for 9 months.

Kia Optima (K5) Tire Pressure [2005-2020] |

Then return to the dealer as this will be a warranty item .


I’m getting it looked at tomorrow. I’m just wondering if the difference in PSI between the tires causes the warning light to come on as opposed to the PSI just being low.

Your tires are under inflated, 26 to 28 PSI is very low, you should have 34 PSI in the tires. This is not a warranty repair.

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Do you not check your tires at least once a month ? Even the 31 is below what the door plaque says . I guess what ever country you are in will have door plaques just as we do here in the US .

You can buy tire inflators that use 12 volts and 110 household for a low price .



If the pressure gets low enough to turn the light on, it means you are not checking your tire pressure often enough.

Low tire pressure causes excessive tire wear and poor fuel economy.

Check them often and properly inflated.


Read your owner’s manual to see what are the possible causes that will trigger this light. And, of course, if your tires are underinflated, you should not attempt any diagnosis until the tires are at the correct pressure. If I were the dealer, and I spent time just to diagnose that your tires were underinflated, I would charge you for that.

Which is WHY it sets a low psi warning. At least add some air to that tire if not set all 4 to the correct pressure when cold which is what your owners manual tells you to do.

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Do you have a pressure gauge for your tires? I use an Accugage dial gauge and find it works well. I fill the tires a couple psi above the level on the door plaque. It’s not too high and gives me a little longer for the pressure to drop over time. Also, as air temperatures drop, the pressure in the tires will too just from being cold. I have to add air every winter. If the temperatures have dropped into the low 40s or 30s where you are, that could be part of the problem too.

I got an inflator and it’s now at 33 and still saying low. The others are at 30 and dont say low.

Fill each tire and road test, sometimes the system needs to see an update from each sensor to turn off the warning.

It looks as if all the tires should be at about 34 psi. Once they’re all inflated properly it will take a couple of miles driving before the sensors reset.

you have to drive the vehicle for a few miles after inflating for it to go off.

Inflators sometimes don’t have accurate pressure gauges in them. I prefer checking with an accurate gauge. I’m not saying your inflator is inaccurate, but it’s worth testing if you haven’t already.

I’m not going off the PSI on the inflator. My car reads out each tire. Yeah when this downpour slows down I’m going to drive til the sensor goes off.

Edit: I suggest not waiting until there’s a flash flood warning to inflate your tires.

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This is getting more complicated than it needs to. Inflate your tires to the psi labeled on inside of your door. Do this when tires are cold, meaning not driven for at least 4 hours. Use a tire gage to set it to the correct pressure. If the correct pressure is 35 then 33 is too low. If the tire pressure is correct using a tire gage and the error warning comes or stays on after you drive 10 miles, then you can take it to the dealer. I suspect you will not have a problem once you properly inflate the tires. The error message only comes on when 1 or more tired are low. Differences in tire pressures between tires does not set an error.

Each tire has it’s own alert. The ones at 29-30 do not say they are low. Only the one I just filled up is saying low, but once I drive for a few minutes the alert should go away.