I was recently driving about 75 mph with adaptive cruise control (ACC) engaged. Because I thought I heard some air coming in the passenger side window, I pushed the button to raise the window. As soon as I did so, I heard a warning “beep” accompanied by the message “DRIVER INTERVENTION”; simultaneously, ACC disengaged. The message then changed to “TRANSMISSION FAULT.” There were no noticeable changes in the car’s performance & I continued driving another 20 mi to my destination. After parking, I restarted the car and the warning message was gone.

Any thoughts on the connection between using the window and the subsequent warnings? With the TRANSMISSION FAULT warning gone, do I need to be concerned?

 

What’s the state of your battery? I once had something similar when using a Bluetooth cassette tape adapter - replaced the battery and it never recurred

 

I second inspecting the battery.

But, if you have no records of ATF fluid change or a transmission service, I would consider that as well.

To better help you we need some information. Is it an XK8 or an XKR? 4.0 or 4.2? What year is it?