Mercedes GLS Hybrid Heating Problem

I understand your frustration with the heating issue in your Mercedes GLS. I have a GLS myself, and I encountered a similar problem not too long ago. The low heating output coupled with an error code pointing towards the automotive valve is indeed indicative of a potential issue within the cooling system's water valve circuit. Have you checked the coolant level to rule out a significant coolant leak? A drop in coolant can definitely affect the heating performance. Also, could you specify the exact error code you are receiving? This might provide further insight into the nature of the valve malfunction. The symptoms you describe could come from a valve blockage as well.

Thanks for the reply Coolant level is fine, so no obvious coolant leak there. I don't have the exact error code on hand, but it definitely mentioned the water valve. Where is the water valve located in the GLS? Maybe I can check the cable and plug connection myself before taking it in.

I comprehend your desire to inspect the connections prior to seeking professional assistance. Disconnecting, inspecting, and reconnecting the implicated harness connector is an approach that may resolve the issue. With caveats, of course, that any self-directed repairs are performed safely and correctly. The automotive valve on your GLS is situated near the engine block, often in proximity to the thermostat housing, as part of the cooling system. Given the hybrid nature of your engine, there may be multiple valves regulating coolant flow to different components. Accessing it may require removing some engine covers or other components for clear visibility and access. I would advise proceeding with caution, or consulting a repair manual specific to your vehicle, as improper handling could cause damage. If you are uncomfortable with this, it may be prudent to take it to a trusted workshop for diagnosis, especially since the error is stored in the error memory, suggesting a more persistent electrical fault. In my case it was the valve. They charged me 95€ to replace it.

Alright, thanks for the detailed explanation Sounds like it's worth taking it to a shop to get it checked out. I'll mention the cable and plug connection issue, and the possibility of a faulty water valve. Hopefully, it's a simple fix. Thanks again for all the help