Low Tire Pressure Light On But Pressures Normal! Why? 2018 CX-5

[CX5Nut]

2018 CX5. While we were near the end of a 300-mile road trip, the low tire pressure light beeped and illuminated. Pulled over and check the tires. All at 38 psi. Turned car on and off. Light stayed on. Drove 1 mile and light went off.

When we got home rechecked all 4 tires and all were still at 38 psi. Then checked the spare in the trunk and it was only 18 psi (supposed to be 60, and this was the first time I checked it in 5 years)

So my question....could the very low Spare Tire pressure have set off the low tire pressure light? If not, any ideas?

Thanks!

 

[ceric]

Not the spare tire. It has no sensor inside.
After 5 yrs, it is normal to be <20psi.
It should be checked every year.

Maybe one of your tire sensor (inside) is failing ... low battery.

 

[ceric]

FYI.

How To: Replace TPMS Battery

In this video I'll show you how to replace Toyota/Lexus Tire Pressure Monitoring Sensor (TPMS) battery. If TMPS battery is low, then at the startup of vehicl...

www.youtube.com

Look messy. I'd just get a new one.
The silicone is there to make it water-proof.

 

[CX5Nut]

Have most people here with a CX5 replaced their TPMS battery after a certain number of years? Have not seen that talked about here. I noticed in the manual it says a blinking low pressure light means the battery is low but mine was not blinking.

Thanks for the link...will check it out.

 

[CX5Nut]

Looking at that video I doubt anyone is replacing the battery! Has anyone here had their battery fail in the sensor in their CX5?

 

[stickerbush]

The tire pressure warning system distinguishes between a low-pressure warning and a malfunction of the TPMS system. From the owners manual:

The TPMS malfunction indicator is combined with the low tire pressure telltale. When the system detects a malfunction, the telltale will flash for approximately one minute and then remain continuously illuminated. This sequence will continue upon subsequent vehicle start-ups as long as the malfunction exists.

You probably experienced a temporary malfunction of the TPMS system, maybe the system was momentarily unable to communicate with one or more of the sensors. Whatever the problem was, it resolved itself. I had this happen yesterday on my 2020, first time this has happened in the 4 years I've owned the car.

 

[CX5Nut]

The tire pressure warning system distinguishes between a low-pressure warning and a malfunction of the TPMS system. From the owners manual:

The TPMS malfunction indicator is combined with the low tire pressure telltale. When the system detects a malfunction, the telltale will flash for approximately one minute and then remain continuously illuminated. This sequence will continue upon subsequent vehicle start-ups as long as the malfunction exists.

You probably experienced a temporary malfunction of the TPMS system, maybe the system was momentarily unable to communicate with one or more of the sensors. Whatever the problem was, it resolved itself. I had this happen yesterday on my 2020, first time this has happened in the 4 years I've owned the car.

Suspect you are right. Have not read of people on here having to replace their sensors so hopefully it was a one and done event, for both of us!

 

[stickerbush]

Have not read of people on here having to replace their sensors so hopefully it was a one and done event, for both of us!

I have a second set of wheels with winter tires and aftermarket TPMS sensors. Those aftermarket sensors started failing after about 3 years and I recently replaced all of them. It was with these tires that I experienced the errant warning yesterday. I've had no failures on the OEM sensors.

 

[CX5Nut]

If anyone has had failed OEM sensors, please chime in!

 

[Koko_Bandit]

Looking at that video I doubt anyone is replacing the battery! Has anyone here had their battery fail in the sensor in their CX5?

Some people probably have and did not know it. Most tire places will add it to the tire installation and many people do not notice.

 

[stickerbush]

Some people probably have and did not know it. Most tire places will add it to the tire installation and many people do not notice.

I'm pretty sure the batteries in TPMS sensors are encapsulated and not replacable.

 

[theblooms]

My CX-5 doesn't have sensors at all. I think it uses wheel speed to detect low pressure.

 

[RedBaron]

My CX-5 doesn't have sensors at all. I think it uses wheel speed to detect low pressure.

Yep, gen 1 used wheel speed, gen 2 uses TPMS sensors

 

[Koko_Bandit]

I'm pretty sure the batteries in TPMS sensors are encapsulated and not replacable.

If so, thye replace the entire sensor. Most tire places automatically tack the charge on the bill. I had to argue with them on our VW and Audis which use the wheel speed sensor.

 

[CX5Nut]

Interesting. We just had new tires put on by Costco 6 months ago and never thought about asking them to replace the tire sensors since I've never had one fail.

 

[stickerbush]

Interesting. We just had new tires put on by Costco 6 months ago and never thought about asking them to replace the tire sensors since I've never had one fail.

Good tire installers will check the sensors and let you know if they need to be replaced.

 

[CX5Nut]

Good to know...I'll need to ask about that next time

 

[Conrad 16.5]

Good tire installers will check the sensors and let you know if they need to be replaced.

How would they check such sensors?

For the sensors that I've seen, there's no way to physically check them since they are not meant to be opened.

I suppose that it's possible to have a device that connects to the sensor wirelessly and, if the sensor supports it, gets battery health info. I'm skeptical though.

 

[CarpeDiem]

How would they check such sensors?

For the sensors that I've seen, there's no way to physically check them since they are not meant to be opened.

I suppose that it's possible to have a device that connects to the sensor wirelessly and, if the sensor supports it, gets battery health info. I'm skeptical though.

Be as skeptical as you want, but there are a plethora of tools to monitor function, reset and perform battery checks on the TPMS.

TS58R TPMS Tool Kits

TS58R TPMS Tool Kits <div class="container"> <p>All-in-One TPMS Solution</p> <p>With the portable TS58R in hand, technicians will be able to view Sensor Battery Life, Tire Pressure, Broadcast Frequency, Sensor ID, as well as tire

www.bendpak.com

 

[stickerbush]

I suppose that it's possible to have a device that connects to the sensor wirelessly and, if the sensor supports it, gets battery health info.

Yes that is how I've seen it done by techs at Discount Tire, with a device that checks TPMSs without removing the wheel from the car.