You mean the light won't stay off. The sensor for the check coolant
light is located on the end of the plastic rod which is part of the fill
cap on the coolant recovery tank or bottle. The tip of this rod has to
be submerged in coolant to keep the light off. If you have to add
coolant to the tank every few days to make the light go out, you have a
leak somewhere which is lowering the fluid level in the tank below the
sensor. The leak could be in the tank itself or somewhere else in the
cooling system. If you can't find a leak on the ground under the car,
it's probably an internal leak in the engine. In that case the coolant
is going out the exhaust pipe as steam, along with the other hot gases.
It's too early to say the 'h' word, but you can guess what might be
causing an internal engine leak.
If there was a problem with the coolant sensor or the wiring of that
circuit, adding fluid to the tank shouldn't make the light go out.
There's a very slight possibility that removing the cap on the tank to
add fluid, might temporarily fix a problem with the sensor or wiring but
I doubt it. Another long shot, the sensor needs to be cleaned. Do this
with a plastic kitchen scrub pad. Don't over do it.
You've probably discovered by now that the light won't go off after you
add fluid 'IF' the engine is running. You have to turn off the ignition
switch and restart the engine to make the light go out. This is because
the engine computer has to reset the fault but it can't do it while it's
Good luck. Hope it's not the 'h' word. ;-)
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