khojo16

Ok i have searched countless threads over countless months....still haven't seemed to solve my problem. I have had the infamous low coolant light in very intermittent patterns, and have tried 4 different low coolant level sensors, still experiencing an intermittent light. It seems as though when I let the car warm up for a while in the morning, and then drive and cruise at low rpms, I don't get the coolant light for the most part, but when I get on it hard and when its hotter outside, my coolant light will almost always come on. Every now and then it just shows up when it feels like it lol. Anyway, my only guess left is that it has something to do with the wires leading to the plug, like maybe a wire is grounding out somewhere because my car is leak free and the coolant level remains full all the time. I realize I have the option of unplugging the sensor, but would rather not. Can anyone shed some light on the two wires for the plug, and where each of them go to?

DAVE00

Dumb question, but are you absolutely sure you are not actually low on coolant and that you have fully bled the whole system?

popstoy

unplug the sensor there garbage .your better off checking level yourself.

wrd1972

Unplug it.

mightymouse383

just unplug it and problem solved......ALWAYS CHECK COOLANT LEVEL, DON'T TRUST THE LIGHT.

khojo16

haha yes i am 100% sure the coolant system is full and it has been bled properly...there was even a point where i tried to continue to bleed the system, but not even a hint of an air bubble will come out...i know i can unplug it, but id rather have the light just working as a fail-safe and also just to know that its possible to have it working...which as of right now doesnt seem like it is...but im also curious as to where those two wires go, if not for the purpose of fixing it, for common knowledge...anyone with insight on this???

userchemical

they go directly to your dash to that light. The sensor does nothing but turn that light of and off.

khojo16

so neither one of them is a ground wire?

shoebox

The black wire is a ground. The yellow/black goes to the dash and BCM.

Have you tried unplugging the sensor and seeing if the light stays out. If it does not, that might suggest that the yellow/black wire is intermittently grounded or the BCM or cluster is causing an issue.

Are you sure your system is really full? It is suspicious that is comes on when you run the engine hard, since that pumps coolant more rapidly and might cause a somewhat low level in the radiator to suddenly go down enough for the sensor to activate.

ACE1252

For some reason, it has taken several hot/cold cycles for mine to finally calm down. I guess that sensor is some type of latching circuit.

I know, right now, my coolant is overloaded with those sealant pellets. I should have just put one in....but put in the recommended about from Chevy and it has turned my coolant a very dark orange. I got to flush it out when the weather gets to where it has zero chance of dropping below freezing.

userchemical

The sensor has nothing to do with how your car runs. It just controls a light on your dash, it grounds out causing the light to turn on.

sealant pellets eh, well that's your problem. your sensor is plugged the heck up. and now your rad and your block will be full of that orange gunk. I would drain the whole system if i were you, try and clean it out. pull that sensor off, replace it or clean it. Then see where you are at. Are you sure you properly drained the air? did you let your engine get up to op-temp and drain both bleeder valves?

Just my 2 cents but i would NEVER EVER try and fix a leak with "sealant pellets" or any other method, all you're doing plugging up your rad, water pump, thermostat, and everything else.

Good luck.

khojo16

yes i am sure my system is really full all the way, and it does seem to come on when i run it harder...do you think my CSR electric water pump would have anything to do with that?? maybe its not spinning fast enough to circulate the coolant...its only about 3 months old and is rated for 37gpm i believe...

shoebox

I missed the EWP. That kinda throws my theory of the coolant lowering when you are running hard. The level should stay the same with an EWP. The pumping should be uniform as opposed to a mechanical pump that would increase with RPM. The only other thing would be if the EWP was not pumping as much at lower RPMs due to lower voltage at that time. The pump should be on it's own direct and fused power through it's own relay.

khojo16

the pump is fused on its own power, and grounded at the passenger side headlight ground bolt....if i turn the key to the on position, i can hear it working, and also can feel the pump working when the engine is on if i put my hand on the pump...
heres another odd thing to consider...today i drove 20 miles to school, car got up to normal operating temperature which is between 170 and 180 due to tuning and 160 t-stat....i got on it hard for most of the way, and no coolant light...but then again it was cold and rainy outside...it only seems to light up when its warmer out...there might be no correlation to that at all, but it seems to never come on when its cold out...and also if i had anymore air bubbles left in the system, wouldnt the temp rise above the normal operating range? i have never gone past 180 with my EWP, 160 t-stat, and fans programmed to turn on at 160...even in stand-still traffic in 80 deg. heat....
also, i can go a couple days at a time without seeing the light, and the it will come on randomly...sometimes it will flicker a little bit and then come on solid...and other times it just comes on solid out of nowhere...

khojo16

just as an update, havent had a low coolant light in 3 days now...not even a flicker...so hopefully that means this issue is gone, and its been rainy and 40 F here in the past two days, and today was sunny and 65 F....so seems like temperature has no role in this either...also, still have never gone above 180 for coolant temp in stand still traffic no matter the outside temperature...