Why is coolant not circulating on s550 Mercedes?

Hello, what is indicating to you that coolant is not circulating? A low coolant message isn't saying that; it's just suggesting the coolant is low and needs added. This message itself may be in error, or there could be a real need for coolant. The air conditioning system is largely unrelated to the coolant message. Sure, an engine that is overheating will also at times not produce cold air from the air conditioning system, but this does not appear to be the primary concern here. Once resolving the low coolant warning issue, then testing with the air conditioning system -- inside the cabin and under the hood -- can begin, to resolve that concern. www.repairpal.com/repair-shops