Blank instrument cluster panel

Sounds like a problem with the dimmer. If work was done to the car, the dimmer may not be completely plugged in securely.

 

I've had the same thing happen two days after getting my 2008 Prius. I'm posting this the forth day. It happened this morning day four also.

Day 2 dash was blank in the morning. Started Prius, dash was working. Stopped car after starting it to run back to house to get something I forgot. Then started the car again, dash was blank, but center console was on and the computer seemed to be running. Drove it four blocks, then turned off the car, without touching the dimmer, pulled the FOB, put it back in. Turned on the car, everthing was fine.

Then this morning. When I started the car the dash was blank. I played with the dimmer nothing happened. The ABS light was lit on the far side but the rest of the dash was dark. I videotaped this as it was happening today.

Also on this second trip (Forth day of owning the car) not only was the dash dim, but I was getting NO SEAT BELT WARNING BUZZER and left my seat belt off while driving to see if the warning buzzer would start to buzz, no buzzer, so whatever was happening was causing the seat belt buzzer to fail to activate as well.

This time as on the second day, I stopped the car after a few blocks to see if I could restore the dash or restart the car to restore the display.

(Was it a loose FOB?) Nope. Before stopping the Prius, I jiggled and pushed on the FOB to see if the FOB was not being sensed. It was solidly in place. Turned off the Prius without removing the key FOB this time.

Turned the car off, the dash was lit and working after starting it again.

4 minutes later: I was to busy playing with some CD's about a 1/4 mile further down the road and decided to stop and get the new CD playing and put away the old one. I stopped to change a CD in a driveway of a closed business. I noticed my headlights were not on and it was morning and safer to have them on so I turned on the headlights. The dash went blank again, but this time the dimmer was in a position that set it to full dim. So the dimmer solved the problem this "third time" the dash went blank. (The ABS light on the far right was still on this time.)
Then I went to the dimmer and found it could be dialed up. It almost seems like there's two dimmer settings for nighttime and daylight operation and one is somehow programmed in perhaps triggered by a computer program measurment of the daylight (a light sensor). That's a theory I'm thinking about with this weird problem. The dimmer works, currently and it doesn't seem like it was giving me a problem where the dash just went off while it was working. I'd think if it was a loose dimmer switch I'd see some reaction while driving.

I'm going to mention this to my dealer and see what they can come up with.

Greg

 

There are two dimmer settings: night and full on. When you turn on your headlamps, the control system assumes it's night, at which point the dimmer wheel becomes operational. To force daytime settings with the lights on, turn the dimmer all the way up until it clicks.

When your headlamps are off, then the spedo and MFD buttons are at full brightness.

The MFD display (not the buttons around the MFD) has its own daytime/nighttime brightness settings, which are persistent. Adjust the MFD to you liking with and without your headlamps on, making sure the dimmer wheel is not in the full up position (otherwise you are forcing daytime mode). The MFD also has a daytime mode soft button which will force the MFD display into daytime, but it's easier to just roll up the dimmer button if you need it in this mode, such as daytime driving with headlamps.

Tom

 

Thanks for the fast reply. This is an interesting "newbie" topic.

I'm going to have to review my video and see what was going on with the dimmer setting. The interesting thing about this is apparently there was a persistant "off state" that had the dash dimmed, but to a novice, the dimmer didn't seem to change it. I'll have to re-read your explaination and look at it with lights on or off and see how the "daylight" settings are affecting this.

What I find interesting is somehow, with some combination unknown to the driver. Maybe just because I didn't have my headlights on. The dash was completely dark and being dark, it even shut off the seatbelt warning buzzer. It would seem to me that this is a type of faulty programming logic in the firmware or design of the Prius, because it would seem to me that there should be no way that the owner should be able to unknowingly turn off the seat belt warning buzzer.

Seat belts are a part of the safety devices imposed by Federal regulations.

It would seem that the Prius might have a flaw which might be a cause for a possible safety recall. Are federal regulations on the books that require a seat belt warning? Or are they optional depending on some kind of strange programming logic in the car?

Greg

 

Found this:
Prevention Institute: Seatbelts: Current Issues

Current Issues Seatbelt design continues to be improved. Energy-absorbing fibers, seat belt tensioners, and height adjusters are examples of new technology making seatbelts both safer and more comfortable. In all new vehicles sold in the U.S., auto manufacturers are also required to install a buzzer and dashboard light to remind occupants to buckle up.

----------------
Looks like the Prius needs a safety recall.

Wow, it seems like I can't get away from finding bugs in software, even when away from the day job.

 

The seatbelt warning shouldn't be affected. The only things that the dimmer dim are the speedo VFD (the blue numbers with speed, gas, etc.) and the buttons around the MFD. If anything else was black, then you may have a problem, or found some really weird state in the control software.

Here is one to watch out for with the dimmer wheel: The lights on the MFD buttons dim at a different rate than the speedo, so you can dim the speedo down to a nice level on a dark night, only to discover that the MFD buttons have gone completely black. It's not a big deal, but it caused me some concern before I realized it was just the dimmer setting.

Tom

 

I do that too, all the time. I find all the corners and boundary conditions.

Tom

 

Maybe it's a bug with my particular vehicle. I guess we'll see. What's interesting is this happens in the morning, so it's probably something to do with daylight running modes or possibly the computer is doing some kind of shift from a night sensing state to a day sensing state as the sun is rising while this is happening. Maybe that's causing the thing to get confused, it didn't quite wake up.

(I know somehow I should be able to blame Bill Gates and a blue screen of death is behind this somewhere. . . )

It'll be fun to debug, find out or discover the problem. Will call the dealer sometime today and talk to them about it. Video tape is sitting in the car with the camera.

 

I did talk to my dealer. They suggested I wait and see if it repeats before bringing it in. Mentioned it may be that it happens "after it sits overnight". Not sure if that's a clue to other blank dash problems occuring after the dealer lets it sit.

The problem hasn't reoccurred.

One interesting thing has happened in the past couple of days, which may be unrelated. I drove 77 miles on 1.14 gallons of gas, but put in the gas at a local BP station letting the gas shutoff automatically and didn't "top it off" May have not fully filled it and got a false new high miliage reading.

Then the next day drove about 80 miles from that fill up went to a different station, expected to have about 1.2 or 1.5 gallons for that distance if I was still driving well. The tank took 2.79 gallons for 38 miles per gallon. 67MPG one day and 38MPG the next? It averages out to 40 miles per gallon, which is not what I've been averaging up to these days. But this is the first time I've driven all day in the rain.

I went back with a gas can and my truck and filled up 2.795 gallons on the same pump in a 5 gallon can to see of the pump was scamming me and gave me less gas. Turned out it was not the pump. So something caused the Prius to take a lot more gas. I was rush hour driving to work and back in heavy traffic. The second day it was raining and the road had water on it. I may have been hyperdriving a lot less, but it didn't seem like anywhere near that 38 MPG rate.

Will continue to monitor this. Maybe it's better to just drive it more miles and fill up with more gallons to check the millage. I thought I read earlier about some kind of "expandable bladder in the tank" on earlier Prius models. I haven't researched that more to find out. Also of course I could have gotton some poorer gas from BP, who knows?

 

Wow, I'm so glad to find someone else with this problem! I had it happen several times in a row last year, and the dealer said they'd never seen it. The did some diagnostics and made some calls- nothing. They were going to check with the regional Toyota folks, but since then (about 5 months now), it hasn't happened again. I did make sure they had it on record, so if it happens again after the warranty expires, it will be on record as a problem before the expiration date. It was definitely NOT the dimmer - I and the dealer checked that first. I would start the car and everything was blank in the dash display, while the mfd was fine. Sometimes, just turning the car off and on again was enough to "fix" it, sometimes not.

 

Did any dealer identify the source of this issue?. I started my car in the garage and everything was blank in the instrument panel/HUD. It DID come on while i was driivng up a mountain about 20 min and 10 miles later and works now. BUT I notice when the car is on, there is no light on the start button (dont we have a amber light that turns to green when we drive. I called the dealer and he said "bring it in" Mine is a 2008 package 6 with 6000 miles.

Any thoughts? Bob

 

Luscious Garage | Hybrid Specialists | Blog | LG TV - Prius Dead Dashboard

There's been a bunch of threads on this lately.

 

Please see this string: http://priuschat.com/forums/prius-main-forum/57445-instrument-panel-problem-video.html

In brief, your combination meter assembly needs to be replaced. Since this is an intermittent problem I suggest that you document it by taking a sharp photo that shows the MFD is on but the combination meter is off.

When the car is READY or IG-OFF, the LED in the POWER button will be off. It will be green when the car is ACC-ON and amber when the car is IG-ON.

 

You mean take a picture of the instrument cluster black while the MFD is on? If I need to do that to prove it to toyota with a brand new car...well lets just hope I do not have to do that. Why do you refer to the instrument lights/HUD as the combination meter? Bob

 

OK, thanks, my power/start button works as you descibe.

Is there suppose to a green circle around the start button before power up when you open the door or am I mixing that up with another car? When I open the car and get in the word "start" glows lightly green. I thought the circle was illuminted as well...?

 

In my experience the problem is the speedo or the little battery. I've found that if the speedo is black then some things simply don't work - ex. the consumption meters on the MFD - and other things may or may not work - the back hatch, seat belt beeps, ability to turn off car normally, reverse lights, the rear hatch release... I figure that if the car must rely on the instrument cluster to know what gear it's in and if it's moving.

Now I'm tempted to try the latch of the back hatch of a moving Prius - my guess is that it's disabled when the car's in motion.