I just had to restart this topic so it gets seen. This saved me sooo much work.. I had the new thermo and was ready to dig in until I read this... It seems to have worked fabulously for me!!!
----- Press and hold the rear wiper and washer buttons at the same time until all L.E.D's light, this will put the heater control head unit in calibration mode, when done 2 L.E.D's (rear wiper and washer) will flash alternately and then stop when complete.
If you're lucky, you now have heat!
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