Coolant light
No its not normal.
Just because you do not have a check engine light does not mean the ECU is not working out a problem!
There are Mazda CX-5s without a temperature gauge, but with a warning light instead.
When the engine is cold, the light is blue. Once the engine reaches operating temperature, the light turns off.
If the light turns red, the engine is overheating.
When the engine is cold, the light is blue. Once the engine reaches operating temperature, the light turns off.
If the light turns red, the engine is overheating.

The ECU activates the blue dash light if and only if the temperatures fall below a set threshold generally on the next engine cycle engine start up. The blue light goes off at 129.9F which is simply an indicator that the water, transmission oil and engine oil have reached the first temperature point indicating that the cooling system and fluid temperature control during cold start is functioning as it should to help an informed driver that there is no engine and transmission and coolant problems. Naturally if there were you would likely also get the check engine light activated. But the blue light going off is not called optimal fluid temperatures. So you should not really state drive normally yet! If that were the case, then those living in ambientes most of the year all day from sunrise is in the high 90s to triple digits exceeding 110F+ would likely never see the blues light even at start up or it would go off in a minute or less from cold start. BTW the Mazda thermostat is for most regions of the world 195f so in a sense operating temperatures would be if using a digitally manual temperature gauge or device not connected to the ECU for fluid temperature information then collecting the temperature readings the transmission and engine oil normalize at the same temperature which would be just under the thermostat at approx.. 180F . So then what about the opposite for people living in extreme cold operating environments, the blue light would take much longer before going out and the operating fluids ,engine and transmission may never reach even 180F and in many documented service records often not even 160F or less.
Honestly the blue light is IMHO not worth confusing the average vehcle owner and Mazda should have just stayed with RED your engines dead LIGHT. Because most drivers will ignore the lights anyway... IMH!!! LOL
And now lets open the discussion to why all auto manufactures temperature gauge seem to have controlled everyone to accept that in the middle of the gauge is correct operating temperature. LOL Riddle me that batman! lol
Last edited by Callisto; May 19, 2025 at 04:18 PM.
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