On the external temperature reading, if you press the top button in the DIC controls to switch to standard units, does the display change to Fahrenheit degrees? If it does not change, there is a problem with the DIC. If it does change, the problem is probably with the temperature sensor.
Please define what you mean by "traction control does not work". Do you see a "Service Stability System" message? Is the ABS trouble icon lit up? Describe all symptoms and any lit symbols or error messages being displayed.
For the rear door window issue, remove the electrical connector from one of the motors and apply 12 volts direct to the connectors. Does the motor turn. This can be done on the vehicle, or you can remove the motor if it is easier to do it that way.
2001 Bonneville SSEi (retired at 365,000 Kms.)
2014 Jeep Grand Cherokee Overland (yes, I know its not a GM)