Low coolant light on with full resevoir

2003 SATURN L200
80,000 MILES • 4 CYL • 2WD • AUTOMATIC
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GEOFFSOCAL
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  • 1 POST
The low coolant light keeps coming on even though the reservoir is full. It will go off once in a while but comes back on again. The temperature gauge stays at the 1/2 way mark.
Apr 23, 2014 at 11:30 AM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
There is a sensor that determines when the coolant is low. Most likely it is bad or the coolant in the overflow bottle is low.
Apr 23, 2014 at 11:42 AM
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AGUNODM
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  • 2 POSTS
It may very well be a bad sensor. I, too, have that same problem with my 2004 Saturn L300 low coolant light. The overflow bottle is full, the engine remains relatively "cool" but the low level coolant light remains on. I've chosen to live with the light and save the $200 for a new sensor. My engine's never overheated but I just keep a close eye on the temp gauge.
Mar 26, 2019 at 5:02 PM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
I totally agree. If there is no overheating issue, chances are the sensor has failed.
Mar 26, 2019 at 5:16 PM
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