I hit a bump in the road and the low coolant sensor came on. I checked the reservoir and the coolant level almost reaches the max level. There are no drips. Does anyone know where the sensor is located at? How do you disengage the sensor? Any input or help would be appreciated. Thanks in advance.

The sensor itself may be defective. I replaced mine and it fixed the problem. There is a magnetic float shaped like a donut that sits around the sensor. If the float moves freely but the low coolant light stays on, try replacing the sensor. It pulls out from the bottom of the reservoir. The sensor is quite cheap ~25 bucks and can be ordered from a Volvo dealer. Make sure to siphon all the coolant out of the reservoir before pulling out the sensor..

The sensor is in the bottom of the bottle. Sometimes the float inside the bottle will stick, pushing it with a small screw driver can free it up, but if it happens a lot, you will need a new coolant bottle, it comes with the sensor installed.
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Rich K. http://www.volvospeed.com/bay13.htm bay13@cox.net