BMW Repair: check coolant level, coolant level, level sensor

Question
Hello Nathan,

The check coolant level sensor appears after about 20 minutes of driving.  The level is always fine, and I had the sensor replaced six weeks ago.  The thermostat was also replaced as I had a "trans fail safe program" issue.  But, the check coolant level continues to happen.  Any ideas?

Answer
I need to know year,model,mileage. But i will give you some ideas, check coolant level when car is cold, when car is warm you cant accuratley check, also make sure the connector is in good shape at the sensor, be sure its clean no corrosion and make sure connector fits tight.  Hope this helps.  thanks Nathan Babbitt        p.s a loose or corroded connector can cause a poor connection and cause the warning to come on.