Mazda false low tire psi warnings

[t1snwrbrdr12]

Lately, especially in rain or high humidity, I’ve been getting tire pressure warnings on my Mazda 6.

The car has an indirect monitoring system without actual sensors in the tires/valve stems.

One time it happened in a downpour, so I chalked it up to a wheel speed being off due to possibly hydroplaning although I didn’t notice it, and although if it did happen, it wouldn’t have happened for a period of time long enough to set the warning.

This morning it came on as well. Got to work and checked tire pressures, all were within 1 psi of each other.

Every time I correct my pressures I reset the Tpms with the reset button.

It bothers me because any time it has actually caught a low tire, the tire is 10+ psi low for it to pick up the issue and set the warning. So now every time it goes off I’m worried I’m 10 or more psi low.

Anyone with knowledge of Mazda know of some common problem or reason for this?

 

[MParr]

Year and model would help the good folks here answer your question.

 

[MolaKule]

I am not very educated on the Mazda system we had the similar problem on our 2008 TrailBlazer.

In our case, the problem was not the tire sensors but a sensor on the steering wheel that was feeding false info to the ECM. The logic in the algorithm that coordinates this info was totally non-sensical.

 

[t1snwrbrdr12]

Year and model would help the good folks here answer your question.

2017 Mazda 6. Didn’t figure it’d matter too much but maybe it would. I imagine most newer generation Mazda with indirect TPMS will have the same issue (if there is some common issue)

 

[t1snwrbrdr12]

I am not very educated on the Mazda system we had the similar problem on our 2008 TrailBlazer.

In our case, the problem was not the tire sensors but a sensor on the steering wheel that was feeding false info to the ECM. The logic in the algorithm that coordinates this info was totally non-sensical.

I’ll search TSBs but last time I did I didn’t find anything that I cared to have done…and my Mazda dealer hasn’t ever updated any of my software even after I asked, doubt they will now that I’m out of factory warranty.

 

[Starman2112]

Does it monitor the spare?

 

[t1snwrbrdr12]

Does it monitor the spare?

Good question. I wouldn’t think so, being that it monitors the tires on the ground via ABS, but I guess they could’ve thrown one actual sensor in a tire and it could be there. I’ve checked it’s pressure before when I’ve had to use it, but it wouldn’t hurt to check it again!

 

[vwmaniaman]

my Mazda 5 has had that twice in 5 years. Tire was about 5 lbs lower. Not a big deal to me. None of my other cars have those sensors.

 

[FordMan59]

Good question. I wouldn’t think so, being that it monitors the tires on the ground via ABS, but I guess they could’ve thrown one actual sensor in a tire and it could be there. I’ve checked it’s pressure before when I’ve had to use it, but it wouldn’t hurt to check it again!

Since it's so easy to forget to check the air in the spare I started airing them up to about 50 PSI. I keep a pressure gauge in the glove compartment so if I need to use the spare and it's still got high pressure I can adjust it when I put it on the ground. I used to not do that but a few years ago I was driving my mom's car on a trip and had a flat. The spare was very low and had to be taken somewhere right away to be aired up after putting it on. Luckily I wasn't in some part of the country where the nearest gas station was 100 miles away. The full size spare had never been on the ground and hadn't been checked in at least a few years. This thread reminded me I need to check the spare in my cars since it's probably been about a year since they were last checked. One of the first things I did when I bought my Versa was go to a junk yard and buy an extra wheel so I could have a full size spare. Donuts are for eating not putting on your car when you have a flat. I've even read that some cars now come with a can of fix a flat and no spare at all.

 

[t1snwrbrdr12]

Looks like (according to owners manual) that spare tire pressure is not monitored. It just states “all 4 tire pressures are monitored indirectly via abs sensors.” Must just be a quirk of indirect monitoring. I still need to see if there’s any updates that pertain to it, but not sure I’ll be able to access that type of info with my resources. We’ll see.

 

[DBMaster]

2017 Mazda 6. Didn’t figure it’d matter too much but maybe it would. I imagine most newer generation Mazda with indirect TPMS will have the same issue (if there is some common issue)

It matters only for the age of the TPMS sensors. The built-in batteries have a lifespan, best I have gleaned, of 8-10 years. My 2012 Mazda3 still has its original sensors. I was going to replace them, preventatively, last month when I bought new tires, but when I learned that tires don't have to be completely dismounted to replace them I decided to wait until they started to go out. The installation cost at Discount Tire isn't any lower if replacing them along with the tires.

 

[t1snwrbrdr12]

you have actual tire pressure sensors. The indirect systems just look for a difference in wheel speed through the abs…no sensors in the wheels.

 

[DBMaster]

you have actual tire pressure sensors. The indirect systems just look for a difference in wheel speed through the abs…no sensors in the wheels.

Ah! Thank you for that. I guess I didn't realize that they made that change. It sounds better to me than the individual sensors with non-replaceable batteries that I have. Thank you for your reply. I learned something today. 8-{D>

 

[Silver]

I have 3 vehicles with faulty pressure monitoring systems. The light stays on, the tires are all inflated properly.

 

[t1snwrbrdr12]

Ah! Thank you for that. I guess I didn't realize that they made that change. It sounds better to me than the individual sensors with non-replaceable batteries that I have. Thank you for your reply. I learned something today. 8-{D>

Personal preference.

My issue with indirect is that when I have a tire that’s actually going low, I’m not warned till it’s around 10psi low. Maybe it’s because I have the 19s with low profiles, so it takes more of a pressure loss for wheel speed sensors to pick up on than a car with taller sidewalls/softer tires.

With actual sensors in each wheel, they sample the pressure randomly or on a schedule, typically when the vehicle is on and the monitoring computer knows you’ve driven a good bit so they don’t waste battery. But this way the manufacturer can program tighter thresholds for when a warning light should come on. Some think this is annoying, some like the accuracy.

I personally would rather not have Tpms than have an indirect system that acts up. I guess it’s only happened twice, but it’s been in the past 2-3 months…just hoping it doesn’t become a regular issue. Because like I said, when I actually have a tire going low, I’m not warned till 10psi lower, which if it’s a major leak that’s already a significant loss, and tire damage could easily occur. I’m pretty in tune with my cars, but 10psi on a low profile tire isn’t very noticeable.

 

[pezzy84]

That is odd - wonder if you have an ABS sensor giving implausible readings occasionally but not enough to trigger ABS errors. Also you don't by chance have 1 brand new tire with 3 worn as I think even tread depth variance would trigger a light.

I agree with you the indirect system is not as precise and takes much longer to report problems. My 2015 Mazda3 GT had the indirect system, had a pothole hit that immediately flattened the front passenger, it was about ¾ mile on surface streets before there was anywhere for me to pull off and the light didn't pop on until about ½ mile driving along at 0 PSI.

 

[t1snwrbrdr12]

That is odd - wonder if you have an ABS sensor giving implausible readings occasionally but not enough to trigger ABS errors. Also you don't by chance have 1 brand new tire with 3 worn as I think even tread depth variance would trigger a light.

I agree with you the indirect system is not as precise and takes much longer to report problems. My 2015 Mazda3 GT had the indirect system, had a pothole hit that immediately flattened the front passenger, it was about ¾ mile on surface streets before there was anywhere for me to pull off and the light didn't pop on until about ½ mile driving along at 0 PSI.

Nope, all 4 tires replaced at the same time.

 

[tcp71]

In my 2013 CX-5 it also has the indirect monitoring system. I changed the winter tire/wheels to the summers in April and got an error, even though the summers were new (all exactly the same diameter) and all 4 were changed at the same time with exactly the same pressure. It took numerous resets before it decided to "like" the new wheel/tires. I would just continue to reset whenever it gets triggered until it decides everything is fine. Probably took 10 times, but now haven't seen the light in months.

 

[TCL]

Lately, especially in rain or high humidity, I’ve been getting tire pressure warnings on my Mazda 6.

The car has an indirect monitoring system without actual sensors in the tires/valve stems.

One time it happened in a downpour, so I chalked it up to a wheel speed being off due to possibly hydroplaning although I didn’t notice it, and although if it did happen, it wouldn’t have happened for a period of time long enough to set the warning.

This morning it came on as well. Got to work and checked tire pressures, all were within 1 psi of each other.

Every time I correct my pressures I reset the Tpms with the reset button.

It bothers me because any time it has actually caught a low tire, the tire is 10+ psi low for it to pick up the issue and set the warning. So now every time it goes off I’m worried I’m 10 or more psi low.

Anyone with knowledge of Mazda know of some common problem or reason for this?

Sometimes the sender near the toothed wheel get dirt/rust accumulated and you get a false/no reading which would set the light.
Also check all of the toothed wheel(s) for corrosion. It usually happens on the the front wheels since they are exposed to the elements. Had this intermittent issue with a Taurus which used the indirect method and I carefully scraped the sensor clean and all was fine after that.

 

[Jetronic]

haven't seen toothed wheels used on cars made in the last decade, except the really cheap/small ones.