I'm sorry to hear about the issue with your 2016 Cadillac Escalade ESV's CUE screen. It sounds like a frustrating situation. While I can't diagnose the problem directly, I can provide some suggestions and possible causes for the black screen issue:
Fuse Issue: One of the most common reasons for a black CUE screen is a blown fuse. Check the fuse box for any blown fuses related to the CUE system and replace them if necessary.
This guide can help:
Software Glitch: Sometimes, software glitches can cause the CUE screen to go black. Try performing a soft reset on the CUE system. To do this, press and hold the power/volume knob for about 10-15 seconds until the system reboots. If this doesn't work, you might need to perform a factory reset on the system (note that this will likely erase any personalized settings). You can try a system reboot as well.
Hardware Issue: There could be a problem with the CUE screen's hardware components, such as the display panel or the connection between the screen and the rest of the system. This could be due to damage or a loose connection during the engine repair process.
ECU or Control Module Issue: The CUE system may have its own electronic control unit (ECU) or module responsible for its operation. If this unit is faulty, it could cause the screen to remain black. Since you mentioned that you suspect two ECUs might be broken, it's worth doing a CAN scan,
you can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.
here is a video to show you how:
Here is one for about $99.00 if you need it:
Backlight Failure: The CUE screen has a backlight that illuminates the display. If the backlight fails, the screen will remain black even though the system is functioning. A faulty backlight may need to be replaced.
Wiring or Connector Problem: During the engine repair process, some wiring or connectors related to the CUE system might have been disturbed or disconnected. Inspect the wiring and connectors to ensure they are properly connected.
Check out the images (below). Please let us know what happens.
Images (Click to make bigger)
Saturday, July 29th, 2023 AT 1:13 PM