93 Cutlass Supreme Low coolant light and check engine light

[CA Cutlass Supreme]

Hi all, Had a "low coolant" light supposedly fixed in 08/15/09 at the radiator shop. The light comes on, on the freeway and goes off when i get back into town. This has been doing this the past couple months, but when i check there is enough radiator fluid in the reservoir. Now i get the "check engine light" below it. I'm thinking of trying to fix this low coolant light myself. I know the radiator has to be drained to replace this "low coolant switch" and an o-ring is needed. Q: How hard is it to do yourself and can someone outline the tools and steps needed to get this down myself. Once I fix that, i'll see if the check engine light comes on again. My details are in my signature below Thanks again! Kevin in Vancouver, WA BTW: I don't even know if there is a code reader still made for this and never used one, so i guess we'll get to that when the radiator coolant switch is fixed? something also has put "&" in my text..don't know what that is all about.

[CA Cutlass Supreme]

I checked the overflow reservoir and it's a tad under full for cold...about 3", but the radiator is topped off (cold check). I started the car and the check engine soon light disappeared. I've sent an e-mail to the radiator shop to see if they can look at this low coolant switch and repair it. I had a radiator and the switch repaired there, (the switch on 2009, new radiator in 2007), but wonder if the switch is faulty.

[edc60]

In the 96 Supreme, the low coolant sensor is on the left side of the radiator, 4 to 6 inches from the top. It is pressure fit into a neck similar to a radiator filler. Look for wires going to the sensor.

More likely you need to bled air from the cooling system. My 96 has 2 points, one near the waterpump/heater pipe area. The other is on the right top.