stim141

On my Clk430 (2000) my gauge cluster shows the correct outside temperature but when I enter the sensor readouts on my climate control the #2 position is WAY off. Say the outside shows 70F the inside reading will show 130 - this causes the climate control to keep the ac on and the heat off. The readout increases and decreases so it seems like it connected to something. I also disconnected the sensor at the bumper and the gauge cluster now shows -36 so the cluster gets its data from the front bumper. I still have to check the readout on the climate control to see if it also shows the same. Does the climate control get its data from the front bumper or somewhere else? What could be wrong - wiring or god forbid the climate control unit? i know the duovalve is fine because when I set both to HI I get full heat. Also the residual heat function works fine. As winter is approaching I'll either be freezing or sweating. Any help would be appreciated.

MarcusF

I believe there is one ambient temperature sensor and the HVAC uses it. The outside sensor is $13 and as you know, is easy to replace.

stim141

This is very strange because I think my car is getting a sensor reading for something other than the tube at the bumper. When first starting out in the morning both the gauge cluster and the sensor data pretty much match. Drive around a bit and let the car idle. The gauge cluster reads correctly but the sensor data will increase steadily as the car sits at idle. Drive again and the temps normalize. I have a feeling that there is another sensor in the engine compartment that the climate control (at least on my car) is getting data. Not good because when you need heat the temps say outside air is in the 50's and the compartment at idle will reach in the 70's or more so it calls for little to no heat or the ac system may be triggered. In stop and go traffic you will get cold or just sitting in parking lot - same thing. I could trace it (major pain).