Speed Sensor affecting TPMS sensors?

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CX-5 Signature
I recently switched to 21" wheels with a 35 profile tire on my 2019 CX5 Signature which caused me to be 3.57% off from the OEM tire spec size. I got aftermarket sensors with my new wheels and mostly the tire pressure light would stay on and sometimes it would go off. I did everything I could do for it to autolearn the new sensors and the longest I could get it to stay off was 1 day then the light would come back on. I ended up taking it to my Mazda dealership this weekend and they diagnosed it saying the speed sensor was throwing up a code and might be causing the TPMS light to come on as they have seen this happen before. They didn't charge me anything but they want to try replacing my aftermarket TPMS sensors with my OEM ones which I still have. Has anyone ever heard of the speed sensor being tied into the TPMS sensor? This would be pretty crappy if the speed sensor is affecting the TPMS sensors and I would have to switch tire sizes if I want the light off.
 
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I know that the Gen1 cars do not have TPMS sensors in the wheels. Instead they detect inconsistent rotation between the wheels to trigger the under-inflated alarm. As for the Gen2's, I'm not even sure if my Gen2 has the sensors or not.
 
Gen2 has actual TPMS with sensors in each of the wheels. The pressure sensor is integrated with the schrader valve assembly. I think it is worth trying to install OEM tire pressure sensors. The TPMS and speed sensors should not be related.
I'm surprised you did not have a check engine light or anti-lock braking light or traction light - any of which might be related to the speed sensor error found by the tech.
I hope you are able to follow up if the OEM pressure sensors fix the issue and if there were any other unintended consequences of going with the larger wheel and tire combo.
 
Gen2 has actual TPMS with sensors in each of the wheels. The pressure sensor is integrated with the schrader valve assembly. I think it is worth trying to install OEM tire pressure sensors. The TPMS and speed sensors should not be related.
I'm surprised you did not have a check engine light or anti-lock braking light or traction light - any of which might be related to the speed sensor error found by the tech.
I hope you are able to follow up if the OEM pressure sensors fix the issue and if there were any other unintended consequences of going with the larger wheel and tire combo.

I got the appointment set for Oct 31st back at the dealership to put the OEM sensors in my new wheels. It is strange that I get no other lights being triggered on the dash like you mentioned. The only light I get is the TPMS one. Every time I start the car I can see the TPMS flash like it is trying to relearn the sensors then it just stays lit up. CX5 drives perfect too, no problems where I would notice anything being affected. Will report back what I find out after the appointment.
 
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Do you know if the aftermarket sensors you had installed were programmed for your car? Some universal sensors need to be programmed in order to work correctly. If you aren't sure, I'd suggest stopping by a tire shop like Discount Tire or the shop that installed your sensors to see if they can program the sensors for you. I don't think they'll need to remove the sensors from the wheels to program them, but they may need a TPMS programming tool.
 
Each sensor emits an ID code to the ECU of your CX5 periodically above X-mph. If the ECU does not detect it after conditions are met, it flashes the TPMS light on the dash.
My guess is:
As sm1ke said, you did not register the sensor ID to the ECU. In workshop manual (if you have one), there is a process. Of course, dealer can do it. Whoever sold you the sensors might have instructions.

Mazda moved from using TPMS sensors in the wheel to speed sensors, and back to TPMS sensors again in new models. My '08 CX9 had TPMS sensors, '14 Mazda3 and '16 Mazda6 use speed sensors. '17 CX5 uses TPMS sensors in wheels. None had/has given me false alarm yet.
 
I got the appointment set for Oct 31st back at the dealership to put the OEM sensors in my new wheels. It is strange that I get no other lights being triggered on the dash like you mentioned. The only light I get is the TPMS one. Every time I start the car I can see the TPMS flash like it is trying to relearn the sensors then it just stays lit up. CX5 drives perfect too, no problems where I would notice anything being affected. Will report back what I find out after the appointment.
Usually the seller should pre-program the aftermarket programmable universal TPMS sensors compatible to your vehicle. If they didn’t, you’ll have communication problem between TMPS module and 4 tire pressure sensors. Go to the sensor seller to re-program them to be Mazda compatible. Autel MX-Sensor 2 in 1 (315MHz + 433MHz) Clamp-in 100% Cloneable TPMS Programmable Sensors is a popular sensor to be used by many. There’s Autel wireless programming tool to quickly update sensors to be Mazda TPMS compatible and there’s no relearn process required. In your case there’s no need to uninstall tires too.


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Update to my situation. I ordered one of those Autel handheld TPMS programming tools from Amazon and it came in this weekend. I did the activation process with the device to all my sens.it sensors and got green check marks for each wheel showing they were all activated and setup per wheel location. Got in the CX5 and drove for about 5minutes and the TPMS light went off. I drove around for another hour and it stayed off. I been driving for the past 3 days and so far the light is off so it looks like my sens.it sensors just needed to be activated so the car could relearn the sensors. Problem is now fixed.

Now here is what irritates me. I specifically made an appointment at my Mazda dealership for this issue. Went in for the appointment as stated in my first post and they had the car for an hour and came back telling me the sensors were triggering the speed sensor causing the light to go off. Their solution was to have me bring in my oem sensors, unmount my new tires and wheels, uninstall my perfectly fine aftermarket sensors and reinstall the oem sensors, remount and balance my new setup. This would of cost me $300 to do from the dealership when all that needed to be done was activate my new sensors which took me 5 minutes to do myself with the device I bought. I don't know if they were trying to rip me off or just incompetent. Wouldn't you thought they would of used a TPMS tool similar like I bought just to trouble shoot it and activate the new sensors in the first place? I cancelled my appointment on the 31st with them since I no longer need it.
 
Update to my situation. I ordered one of those Autel handheld TPMS programming tools from Amazon and it came in this weekend. I did the activation process with the device to all my sens.it sensors and got green check marks for each wheel showing they were all activated and setup per wheel location. Got in the CX5 and drove for about 5minutes and the TPMS light went off. I drove around for another hour and it stayed off. I been driving for the past 3 days and so far the light is off so it looks like my sens.it sensors just needed to be activated so the car could relearn the sensors. Problem is now fixed.

Now here is what irritates me. I specifically made an appointment at my Mazda dealership for this issue. Went in for the appointment as stated in my first post and they had the car for an hour and came back telling me the sensors were triggering the speed sensor causing the light to go off. Their solution was to have me bring in my oem sensors, unmount my new tires and wheels, uninstall my perfectly fine aftermarket sensors and reinstall the oem sensors, remount and balance my new setup. This would of cost me $300 to do from the dealership when all that needed to be done was activate my new sensors which took me 5 minutes to do myself with the device I bought. I don't know if they were trying to rip me off or just incompetent. Wouldn't you thought they would of used a TPMS tool similar like I bought just to trouble shoot it and activate the new sensors in the first place? I cancelled my appointment on the 31st with them since I no longer need it.

Happy to hear the problem was fixed!

Unfortunately, that sounds like typical dealer experience/behaviour. It could be a case of incompetence, but most likely they were just trying to get you to spend money. :(
 
Happy to hear the problem was fixed!

Unfortunately, that sounds like typical dealer experience/behaviour. It could be a case of incompetence, but most likely they were just trying to get you to spend money. :(
I guess you always have to factor the "not made here" mentality, especially when it can be so profitable.
 
Update to my situation. I ordered one of those Autel handheld TPMS programming tools from Amazon and it came in this weekend. I did the activation process with the device to all my sens.it sensors and got green check marks for each wheel showing they were all activated and setup per wheel location. Got in the CX5 and drove for about 5minutes and the TPMS light went off. I drove around for another hour and it stayed off. I been driving for the past 3 days and so far the light is off so it looks like my sens.it sensors just needed to be activated so the car could relearn the sensors. Problem is now fixed.

Now here is what irritates me. I specifically made an appointment at my Mazda dealership for this issue. Went in for the appointment as stated in my first post and they had the car for an hour and came back telling me the sensors were triggering the speed sensor causing the light to go off. Their solution was to have me bring in my oem sensors, unmount my new tires and wheels, uninstall my perfectly fine aftermarket sensors and reinstall the oem sensors, remount and balance my new setup. This would of cost me $300 to do from the dealership when all that needed to be done was activate my new sensors which took me 5 minutes to do myself with the device I bought. I don't know if they were trying to rip me off or just incompetent. Wouldn't you thought they would of used a TPMS tool similar like I bought just to trouble shoot it and activate the new sensors in the first place? I cancelled my appointment on the 31st with them since I no longer need it.
Thanks for the update and glad to hear the problem has been resolved. The https://www.amazon.com/dp/ (commissions earned) usually runs close to $300. I was wondering why could you find the TPMS sensor seller to program the sensors for you instead of getting a pretty expensive one-time use tool?
 
Thanks for the update and glad to hear the problem has been resolved. The https://www.amazon.com/dp/ (commissions earned) usually runs close to $300. I was wondering why could you find the TPMS sensor seller to program the sensors for you instead of getting a pretty expensive one-time use tool?
I ordered the wheel and tire combo package online so it wasn't a local option where I could just take it to them to fix. I'm sure I could of taken it to Discount Tire or where ever but after taking it to the dealership for the same thing and hearing what they told me I figured I'd try to fix it myself first before taking anywhere else. The Autel programming tool I went with was model TS408 which was $160 and I already shipped it back today for a full refund. The one thing I like about shopping on Amazon is the ease of returns.
 
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...... Now here is what irritates me. I specifically made an appointment at my Mazda dealership for this issue. Went in for the appointment as stated in my first post and they had the car for an hour and came back telling me the sensors were triggering the speed sensor causing the light to go off. Their solution was to have me bring in my oem sensors, unmount my new tires and wheels, uninstall my perfectly fine aftermarket sensors and reinstall the oem sensors, remount and balance my new setup. This would of cost me $300 to do from the dealership when all that needed to be done was activate my new sensors which took me 5 minutes to do myself with the device I bought. I don't know if they were trying to rip me off or just incompetent. Wouldn't you thought they would of used a TPMS tool similar like I bought just to trouble shoot it and activate the new sensors in the first place? ....

I'm glad your problem is fixed. I'm no fan of stealership service departments but I can understand their solution of using o.e. equipment (your o.e. tpms). I would not expect them to deal with your aftermarket part problem. I don't feel like they were trying to rip you off or incompetent but rather offering a solution using mazda parts.
 
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