GregH wrote:Check the published thermistor curve in the service manual EVB-19 (2013) or EVB-22 (2012)... Sure doesn't look flat from 0 to 10C to me!
I appears the ADC and degreesC value on the canbus are linearized but the value displayed on the eyebrow has been curvature corrected. I shut the passenger door on a thermocouple such that it sits about 1cm away from the door just above the side mirror. Monitoring with my Fluke which has 0.1 deg accuracy, I can say that the eyebrow readout matches very well with the Fluke *once equilibrium is reached*
. It takes about 10 minutes for the dash readout to settle, but when it does it is within 1 degree of the Fluke measurement (the Fluke responds very quickly, within seconds) however the canbus readout is often as much as 5 degrees off. For example, this morning, after being on the road for about 20 minutes, I measured 43F outside and read the same on the dash, but got 38F from the canbus. I think we need to start collecting some more datapoints of *real* temperature to fill out our lookup table properly. My data suggests the dash is a good measurement - as long as it has been at reasonably constant temperature for at least 10 minutes. So if any of the folks living the the north can grab a datapoint or two along with the canbus temp at the low extreme, I can get the upper extreme here in a few months and we should be able to fit a curve. Remember, only to trust the dash after you've been driving at least 10 minutes.