Speedometer And Fuel Guage Failure and keeps going on and off

[Kadrisoft2006]

hi all
The speedo an fuel gauge has suddenly stopped working on my 2007 yaris leaving me in a state where I have nothing to tell me how much fuel I have left, how fast I'm going and how many revs I'm doing!.
but when i unlpung and plug it agian it working , and after iam turn off the einging and left the cars for 10m it turn of again.
plz show this video to more information .

https://youtu.be/bpqx1283QW0

any help plz.

Speedometer And Fuel Guage Failure and keeps going on and off.mp4

[Mooly]

Its very hard to diagnose faults like this. First thing to try is disconnecting the Battery for an hour or two (with everything else connected). Failing that and I would look on the instrument panel for any kind of 'backup' power supply, typically a 'supercap' or 'memcap'  or traditional nicad Battery.

Those are really the only two easy to check items and it is possible the Yaris panel doesn't even include a backup supply.

[Kadrisoft2006]

3 hours ago, Mooly said:

Its very hard to diagnose faults like this. First thing to try is disconnecting the battery for an hour or two (with everything else connected). Failing that and I would look on the instrument panel for any kind of 'backup' power supply, typically a 'supercap' or 'memcap'  or traditional nicad battery.

Those are really the only two easy to check items and it is possible the Yaris panel doesn't even include a backup supply.

thanks for your relpay .

now iam disconnected my Battery , and after  3hour i will show the result.

im unplug my speedometer and open it,clean all connector ,but the same problem.

my yaris  model is:NCP90L-AHMRK

my speedometer model : 8380052b00 

[Kadrisoft2006]

after tow hour from deconnecting my Battery an reconnect it ,the resulat is the same , any other solutions.

[Mooly]

I'm afraid not. Investigating it further would need quite a bit of work. I think much depends on where all the electronic processing for the display is done... for example is the display simply that, a display panel, or does it also contain all the electronics to process the data needed. You would need to look back at the unit that this display panel connects to and that is probably not a repairable item.

It would also be worth asking a Toyota dealer whether they have encountered this issue before.

Also, the main green display itself looks to be a VFD (Vacuum Fluorescent Display) and those need a couple of odd voltages derived from a small 'invertor' type power supply. It is possibly that 'invertor' is not starting (but does when you continually connect and disconnect the main lead) but again, you are into more specialised electronic repair.

No easy answers for this one at the moment. 

[Kadrisoft2006]

iam buy new speedometer and it working normaly so the problem in my old speedometer

thanks for all your helps.

[Mooly]

That's great. Pleased to hear you have it sorted.