Thanks for the replies. I’ve not, nor intend to mess with it. I only took the fill cap off to see if there was coolant underneath.

 

Your post indicated you wanted to add coolant.
Never add any fluids (excluding fuel) or make any adjustments to your vehicle while under warranty unless done so by Mazda qualified technician.
Many owners are not aware their warranty covers towing the vehicle.
Any "perceived" issues (like your coolant one) you should call you dealer and have them tow it to their facility or have them "officially" make the call to do something else to fix the issue.

Also welcome to the forum and please let us know what the dealer and you find was the issue.

 

It's probably a faulty thermostat, technically the CCV (coolant control valve), but it appears just the thermostat fails, I have a 2021 NA CX-5 with the same issue.

It will become more frequent with dropping morning temps and your vehicle will not warm up quickly.

Note: P0126 is inadequate coolant temp, not level.
https://obd2.com/dtc/p0126-insuffici...ble-operation/
Most likely, thermostat stuck open and not able to close loop warm up.

Once it logs 3 events you will receive a dashboard engine light.

It can be cleared by standard obd2 reader easily.

But to get it repaired easier, the dealer will want the 3 P0126 codes stored with engine light lit up.

I'm in Pennsylvania. YMMV

MC-11003350-0001.pdf

 

Sorry but your information is really interesting. I can read that you are not by any means a trained Automotive Diagnostic technician or your information would have been more how things in this world work.
The TSB gives and states below and I copied and paste

DESCRIPTION Some customers may experience a check engine light ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: • Engine takes longer to warm up. • Engine temperature gauge fluctuates. • Low coolant temperature indicator (blue) light stays on longer or turns on while driving. • Poor heater performance, especially at idle
Bottom line is at best another DIY posting

But often because these are written for professionals in the Mada service department and often over looked by DIY is:
1. Verify customer concerns and check the coolant temperature in the freeze frame data.


I can sum up what you don't know by your opening sentence and I quote you " It's probably a faulty thermostat. This indicates a guess on your part

 

I can sum up what is likely a big insecurity.
It's a known issue and you don't know your obd2 codes.
Have a nice day.

 

profile sums it up…


There are 2 hundreds of DTCs and 2 basic types. DTC (P, B, C, U , followed by 1st, 2nd, , 3rd & 4 number or letter then are they platform specific or common SAE Codes) are not so much what they are but how to interpret them to begin a systematic testing of the many possible causes for them . Also they are not by themselves because most common DTC will also effect the I/M monitors which is also another useful tool to knowing where to start looking for the actual cause of the DTC and or the issues with the operation of the engine or engine and transmission combination.
Part of the OBD and CANbus systems from 1995 to present and more *specific from 2002 to about 2020 to 2026 require first some service experience doing even minor Diagnostic evaluation experience before being able to help solve DTC related issues. Then what about the DTC that are non specific or the anomalous DTC? While the ECU programing has limits to reporting it is also not uncommon the ECU programing uses standard DTC to generate even if the actual cause triggering the ECU to show a DTC for that to be an anomalous DTC. Hence DTC are a starting point to collect all the information about the vehicle and then start testing suspected causes. My experience show that a DTC is not the cause but the symptom(s) of an issue.
So going back to why this is such a BIG deal…..even the Mazda TSB states to confirm the cause before the service. A good currently certified Automotive Diagnostic Technician does exactly that…. Test the systems or parts suspected to have caused the DTC before randomly replacing parts.

No insecurity here just don’t like BS guessing with bad information especially from a new member and their first post.

 

Just yesterday error code P0126 popped up on my CX-5. I read the code and cleared it. Now I wish I had not done that as the dealer would want to see code. Do you think if problem persists the light will come back on? Or have I just screwed myself?

So far I have driven about 70 kms and the code has not come back. Running at about 75 Celsius in weather that is around 2 Celsius.

Thanks

 

Stop hi jacking thread. 3 different threads asking the same question. Not everyone jumps immediately to answer threads ..

all other members pop over to his actual thread here if you want to answer him. I already did . Lol

https://www.mazdaforum.com/forum/maz...me-back-56260/

 

Sorry. I screwed up. I thought I had deleted the 2 replay before creating a posting. Obvious I did not. Sorry