During a recent vacation, while driving at night, the MPH display went black. I completed the drive to the hotel, resolving to change the fuse in the morning. When I started the car in the morning, the display was still black. I checked the fuse I thought should be involved (#22), but it was good. The MPG / MPG screen was still bad. Not wanting to drive an additional 400 miles back home without a speedometer, I called the closest dealership to get an appointment. The 2010 has 33K miles on it and is under warrantee. When we packed up and started the car for the trip to the dealer, everything was working. One week later and all is good. I plan on getting this anomaly recorded with Toyota just in case it happens again after the warrantee runs out. Has anyone else seen this issue, and if so, what was the root cause. Thanks.
Several people have had failures of the displays. I don't know the cause but the solution has usually been replacing one side or the other (or both) of the instrument display. Having it documented is a very good idea. I doubt they would replace it if it were not out when you took it in but I would ask anyway. I would remind them it's a safety issue, which it is of course.
The MPH display is actually a reflection from electronics below the top of the dash. That is how the TouchTracer overlays the gas gauge and the mpg gauge. Any chance you had a business card or other piece of paper blocking the area just below and in front of the display. Others on here have had this same issue. If you look in front of the MPH display you will see a rectangle cutout just in front of and below the display. Take a piece of paper and slide it over the rectangle and you will see the display disappear again.
Often cause for many on here has been that their dimmer switch got rotated all the way down blanking out the screen. Check that real quick to see if it is dimmed all the way down to where it turns everything off. If the dimmer is in fact all the way up on full bright, take it to the dealer and have it documented/repaired. Edit: Of course, check if something is obstructing the reflection of the MPH, I did something one should not and assume you knew if something were in there blocking the reflection.
My money is on a business card, phone, small diary or similar being in the way and stopping the display being reflected upwards. I've done that myself a couple of times.
I know this is an old post, but I wanted to add this in case anyone searches it like I just did. The dimmer was not the case for my 06 Prius, nor the screen being blocked. I hopped on Youtube and found a video of someone unplugging their 12v battery for 30 seconds to reset the car and that fixing it.. this seemed too sketchy for me until I found about 12 more of the same videos.. so I gave it a try.. and I have all my dash lights back!! So I would say it’s absolutely worth a try. I just did this about 30 minutes ago, but I’ve gone out and started the car 4 times to check and see that it’s still working and it is! I hope this helps someone as well as it did for me.
Sadly, it will likely come back and get worse (but, hopefully not) search for combination meter problems here, there is a well-known flaw. EDIT: Please disregard this info that was based on Gen 2 problems--missed that I was in Gen 3.
Oops, my bad, combo display is a known issue in Gen 2 and was the subject of a warranty extension TSB, I do not know of anything like that for a Gen 3. Sorry for the confusion. (need coffee)