I am getting an Engine Coolant Low warning with a RED light that does not seem to be related to the coolant level in the reservoir. It comes on and off while driving at random times, both on short drives and long trips. There does not seem to be any associated temperature issues as the temperature from scanner indicates a steady 195 deg F when the light is on and when its not on and of course the needle never moves above normal. I seem to remember years ago I had a valley hose leak that would trigger an AMBER Low coolant level light with a noticeable drop in the coolant reservoir that was easily remedied with some 50/50. Does anyone know the difference between the basis of the RED and AMBER warnings? I get no codes obviously related to coolant when I scan, right now only a pending p0111 code.

 

short the connector for the level sensor and see if it goes away


might be time for a new tank anyways

 

Xalty, the tank was replaced in 2016 and 2018 (new tank cracked under warranty). shorting the sensor turned the light off while idling in driveway but it came back on short test drive. Now light seems to be constant. Temperature stays at 196F and drops a few degrees (192F) when max heat/fan is blowing as one would expect though I could not seem to get the aux coolant pump to activate. Any thoughts on "jumping" the aux pump to verify it is functional?

 

Update: I removed the coolant level sensor and tested it electrically. It is working correctly. I reinstalled and drained the coolant reservoir. refilling the reservoir turned off the engine coolant low light. draining the reservoir again illuminated the warning light again. repeat several times to verify operation of the float and the sensor switch. Short drive, within a mile the Engine Coolant Low warning is back. What are the chances of the sensor switch having an intermittent failure? I am trying to avoid throwing $50 at a new tank/sensor for no reason especially since I have a tank that ACTUALLY holds pressure and doesn't leak. I had a crazy thought that perhaps fluid pressure in the small hose from the tank at the bleeder to the thermostat housing is somehow forcing the float down. I am at a loss. Help, Anyone? Obi Wan?