HUD Not working

My HUD turned itself off the other day, I simply turned it back on, I'm assuming you tried that already.

 

The HUD is turned on and off from a switch located on the panel to the left of the driver's knee. It is possible that it got pressed or bumped inadvertently.



Although the HUD settings are controlled through the Multi-Information Display ("MID"), the on/off function is controlled by the switch as shown above.

 

My 2017 Prime's HUD has begun to exhibit unusual operating characteristics. It is slowly and randomly changing brightness from its usual highly-visible state to dim to off and back. It does this in a seemingly random pattern over the course of five or ten seconds or longer. Kind of like the random cycling of some kind of Christmas tree lights.

I have made a service appointment with the Toyota dealer but never have total confidence that they really understand the Prime. I believe that Toyota has had Heads-Up Displays on other models for a number of years, so maybe they'll know how to diagnose this and get it corrected -- or maybe not.

Has anyone encountered this problem or have any suggestions or comments that I should offer the service tech?

 

Not specifically HUD, but two others I've seen recently concerning the dash behavior.
touchscreen intermittent failure | PriusChat

Software he’ll, app computer resets | PriusChat

 

I know that the display becomes barely visible when one stops behind another car at night and the rear end of the other car is illuminated by the Prime's headlamps, thus causing a very bright background.

But his variation in brightness can occur when driving on at night with a normal dark background or during the day. It also can affect the left hand portion of the display leaving only the speedometer readout visible.

I assume that the HUD display is a back-lighted LCD panel, so this could indicate a failing LCD -- but I am smart enough to avoid trying to diagnose something I know little about.

 

I have the same issue with HUD changing brightness randomly without any change in the environment ...
This issue started to happen after I've played with two connectors which are behind a panel close to the drivers left foot.

 

The problem seems to have resolved itself. Of course, I first made an appointment with dealership's service department but the problem went away right after making the appointment and, when I got there, they could not reproduce the problem.

So far, it has not recurred.

 

I'm actually a Gen 4 user but I just happened across this thread(mine also has a HUD) the HUD uses reflections to produce the image on the windshield, different light angles, even ones not visible to the driver could dull or numb the projections. Things such as light reflecting off windows, street lights, etc, could cause those issues too. Though, I don't know if anyone has taken the HUD apart, but I have a nagging suspicion that the HUD has a light sensor to adjust the projection intensity, so that might be whats doing it.

Also just so that is here in case someone else encounters this, there might be a case where the HUD button is turned on but the HUD is not appearing. If someone messed with your settings or you're a new driver, it is possible that the HUD's project positioning is wrong. You can check the setting in the monitor using the controls on your steering wheel. When you access the setting, you can set the position, try moving it up or down to see if the HUD is actually just out of view. You can also adjust your head's positions to see if the HUD appears at a different angle and then access the settings to adjust it accordingly.