Another low coolant light thread

[dhirocz]

...this thing is about to drive me nuts.

Over the last month I've been fighting this thing. I started getting low coolant alarms, coolant wasn't low. They would randomly come and go while driving.

I checked the old sensor and put in a new sensor from my KW dealer. It became less temperamental...but kept doing it. Module was old and jumper harness between the sensor and module was a little weathered and beat up so I replaced them too, with paccar stuff.

Now here we are again. Still doing it randomly! Now, I do have to put coolant in it occasionally, but not in large quantities. If I drive it nicely it doesn't use much, I haven't put any in for a couple of weeks now. I drive it mostly across town, two trips a day, 6 days a week.

When it does it, the light will stay on, even if it's key on engine off, cap removed. Sometimes it gives me a CEL with it, sometimes not...I'm thinking it might be wiring related and I need to do a resistance check between the sensor and the ECM. Anyone have a pinout?