i have a problem with my honda fit gd(2007 model), the coolant temperature stays on after starting for a few seconds or even before engine warms up. i already changed the thermosensor and added some coolant but its still overheating. thermostat is working, continuity from the socket is good. i dont suspect a head gasket leak because coolant looks clean and doesnt doesnt bubble out. i need help, i'm frustrated.

 

The BLUE light? Normal to stay on until the engine gets partway warmed up.
Read your owners manual for more info!

 

i know the blue will stay on until engine warms up but my problem is the red light that says "H" meaning it is overheating and it starts to light seconds after i crank the engine.

 

OH. Well why didn't you say so?

First I'd want to be able to read live operating data on a good scanner (or equivalent) so I can find out what the PCM is seeing.
Then use that info to make decisions on what the next step will be.