Low tire pressure on continuously

[muttleytm]

2013 CX-5

I have only had one other car with a tire pressure monitor and it didn't use pressure sensors, it used the RPM sensors for the wheels. It did work and all of those times it was pretty obvious which one was low.

When the low pressure light came on I checked all the tires and they were all pretty close. I filled them all to 32 and started monitoring every day.

The pressures were all pretty close and sometimes have gone up. Some days have been warm and others cold so that may explain that, but I've even graphed it, well for about three or four days and don't see any one tire with much of a downward trend.

I don't really have time to stop at a tire shop for them to look at all the tires and the sensors, plus try to sell me sensors. I got it used as well.

I first would like to know how this system works. I do see nothing is happening very fast so I can just proceed as if I don't have the pressure monitoring system. Maybe someone knows how to approach this.

Thanks

 

[wlong01]

If you have a 2013 I don't believe it has sensors. It uses some algorithm based on tire rotation.

When you set all the tires to 32 psi did you press and hold the TPMS button?

 

[muttleytm]

I went online and did what it said to reset it. As I recall I did something else and the light went off and stayed off for the rest of the time I drove it that day and was lit the next day. I think I did press and hold it. I don't recall if I had to do it while the car was on or starting or something.

 

[stack316]

I use jansite tpms bought from Amazon on 3 cars works great.

 

[paris1]

The system reads tire rotation off the ABS sensors and monitors for variation from the point when the TPMS button was pressed. You may have a damaged ABS wire on one wheel which would throw the system off.

 

[dunhillmc]

does it have a tpms reset button? I think that went away on the CX5 with the 2018 model

 

[wlong01]

does it have a tpms reset button? I think that went away on the CX5 with the 2018 model

The OP has a 2013.

 

[RRR]

Hi, I've been using Mazda cars for a few years now. I had the same problem in a 2013 Mazda 3. There's one sensor in each wheel. Each sensor has a battery that runs down. If one sensor stops working - the light comes on. In my case, one sensor failed. Soon, the second, third and fourth may fail. It's most often related to a dead battery. If you want to check which wheel is giving an incorrect signal (no signal), it's enough to have one extra Mazda wheel with a working sensor and swap them with each wheel one by one. In this way, at a low cost, we can determine in which wheel the sensor is not working. The mechanic said that after a few months the next sensor will fail and it's better to replace all four. Mazda sensors are expensive. He offered non-original new ones for $80 for one sensor. After getting to know what's not working and why. After calculating how long it would take me to change the sensors and how much it would cost, the light stopped bothering me and I check the pressure from time to time .

 

[Moonlighter]

Hi, I've been using Mazda cars for a few years now. I had the same problem in a 2013 Mazda 3. There's one sensor in each wheel. Each sensor has a battery that runs down. If one sensor stops working - the light comes on. In my case, one sensor failed. Soon, the second, third and fourth may fail. It's most often related to a dead battery. If you want to check which wheel is giving an incorrect signal (no signal), it's enough to have one extra Mazda wheel with a working sensor and swap them with each wheel one by one. In this way, at a low cost, we can determine in which wheel the sensor is not working. The mechanic said that after a few months the next sensor will fail and it's better to replace all four. Mazda sensors are expensive. He offered non-original new ones for $80 for one sensor. After getting to know what's not working and why. After calculating how long it would take me to change the sensors and how much it would cost, the light stopped bothering me and I check the pressure from time to time .

The 2013 CX5 doesn’t have pressure sensors in the wheels. So your advice , while well intentioned, isn’t relevant to this case.

In a 2013 CX5 it works off the abs sensors. It senses the difference in rotation (circumference) caused by low pressure in the suspect tyre.

 

[dunhillmc]

from the 2013 owners manual:

Tire Pressure Monitoring System
Initialization
In the following cases, system initialization must be performed so that the system operates normally.
A tire pressure is adjusted.
Tire rotation is performed. A tire or wheel is replaced.
The battery is replaced or completely drained.
The tire pressure monitoring system warning light is illuminated.

Initialization method
1. Park the car in a safe place and firmly apply the parking brake.
2. Let the tires cool, then adjust the tire pressure of all four (4) tires to the specified pressure indicated on the tire pressure label located on the door jamb of the driver's door (door open). Refer to Tires on page 9-7.
3. Switch the ignition ON.
4. While the vehicle is parked, press and hold the tire pressure monitoring system set switch and verify that the tire pressure monitoring system warning light in the instrument cluster flashes twice and a beep sound is heard once.

 

[N7turbo]

TPS is useful while driving as well, to be alerted to something that happened (nail in a tire comes to mind, had many of those myself).

 

[muttleytm]

I've been busy and haven't checked in a while, but none seems to be getting low.

I think it may be a sensor issue that picks up the signal on the axle or hub. Someone suggested picking up a new one and just swapping it out one by one and see. Seems like it can be tested by measuring resistance. Should have some, but not infinite and not none.

On the other hand the car also has ABS and the wheel speed signal seems like it would be a critical part of the critical braking systems. I am not getting any sort of signal or service ABS message that I can see. Seems like this condition would trigger that.

Anyone know about this? It may be a while before I get a chance to look. For that matter other than around the wheels I don't really know specifically where they are or the best way to get at them or their connectors.

 

[Ranman57]

Pure speculation here but since it depends on rotational speed to see differences in tire pressure maybe you have a tire that's more worn than the other ones triggering the system. It might be worth checking tread depth on all the tires to see if they're worn evenly.

 

[dunhillmc]

I've been busy and haven't checked in a while, but none seems to be getting low.

I think it may be a sensor issue that picks up the signal on the axle or hub. Someone suggested picking up a new one and just swapping it out one by one and see. Seems like it can be tested by measuring resistance. Should have some, but not infinite and not none.

On the other hand the car also has ABS and the wheel speed signal seems like it would be a critical part of the critical braking systems. I am not getting any sort of signal or service ABS message that I can see. Seems like this condition would trigger that.

Anyone know about this? It may be a while before I get a chance to look. For that matter other than around the wheels I don't really know specifically where they are or the best way to get at them or their connectors.

did you reinitialize the TPMS system after setting the tires to the correct pressure?

 

[Lazy2.5]

none seems to be getting low.

I would stop wasting your time with it.

My 2015 Mazda6 has the same sort of TPMS as yours. I get false alarms from time to time. Have you tried pressing and holding the button to the left of your steering wheel to reset it?

 

[muttleytm]

Just to get back with you on this. I had sort of forgotten about this. I was keeping track of the tire pressures (and outside temps) for over a week and couldn't detect which one. The Tire pressure light remained on the whole time. I just happened to be next to the right rear tire the other day and noticed is was quite low (about 19PSI). I added air and then reset the system. It would light up again, usually the next day and the tire would again be obviously low.

Finally got a chance to get to a tire shop and it was repairable. I had driven over a screw.

I guess it must have a premonition mode or something. Maybe it was just a coincidence. I was starting to think a it might be a bad sensor or something, but it seemed that would trigger and ABS or TCS light. But, being too busy to actually look into anything. Hopefully it is solved.