Dashboard Light turn off (Not a dimmer switch issue)

Discussion in 'Gen 3 Prius Main Forum' started by SuddenlySS717, Sep 22, 2016.

  1. SuddenlySS717

    SuddenlySS717 New Member

    Sep 22, 2016
    franklin, ma
    2012 Prius

    I'm hoping someone can help me. Tonight when I was driving, all the lights/icons on my dashboard would shut off (my headlights were on at the time) this would happen randomly, so no it doesn't have to do with the dimmer switch...I would switch the headlights off and on really quickly, then the dashboard lights/icons would be back, but only for a short time before going out again. At some point during my 45 min commute I just let them stay off, by the time I got home the "Ready" icon and the park/drive/reverse icons were lit up, along with the headlight icon that had been there the whole time, but nothing else...I'm not sure if these ready & gear lights came back on while I was driving (previously EVERYTHING was black except the headlight icon) or whether it was because it was now much darker so they were noticeable.

    The 'maintenance required' sign has been on my dashboard for weeks. I know, I should just get it in for maintenance work...however, until tonight there were no problems, and I know that maintenance sign comes on after a certain number of miles. This is sort of a separate topic, but do most people think it's necessary to go in for maintenance every single time this happens? The sign comes up after a certain number of miles, and I have a long commute to work so those miles add up fast and t feels like I JUST went in for the scheduled maintenance.

    I'm also wondering if the dash lights going out also have something to do with that, like if you ignore the maintenance display for a while it's built to have those go off to make you go in for maintenance?

    I probably will end up going in, but I'm just disappointed with my local dealership over a huge mess up I had with them earlier this year (all their fault)

    So my questions are:
    -Dash lights going off - Why does this happen, and is it related to the scheduled maintenance?
    -Is there a way I could fix it myself? (I found forums on this issue with older Priuses but I have a 2012).
    -What are people's opinions on going in each and every time maintenance display comes on automatically, is it worth doing?

    Thanks in advance
  2. ChapmanF

    ChapmanF Senior Member

    Mar 30, 2008
    Indiana, USA
    2010 Prius
    I strongly doubt it has anything to do with the scheduled maintenance. The car isn't designed to play mind games with you just because you're overdue for some scheduled maintenance.

    You just need to proceed the old-fashioned way, gather as detailed information as you can about when it happens and what lights/displays are affected, and start following the troubleshooting steps in the repair manual and/or eliminating the common factors you identify in the wiring diagram (both of those references can be found on techinfo.toyota.com).

    When you turn the dimmer control to its brightest setting (should be a click), do the symptoms change at all?

    Quite possibly, depending on your interest, enthusiasm and skill level. Easier to say when we know more about what the trouble is.

    My suggestion: just learn to DIY the most common, frequent maintenance tasks ... then when you get the reminder, just take care of it yourself. :)

    Raytheeagle likes this.
  3. BZzap!

    BZzap! Senior Member

    Jun 13, 2012
    2012 Prius
    Regarding your instrument lights: could be the sentinel system. During the day the backlights are brightly lit for bright ambient light conditions. As it gets dark around dusk the instrumentation lights will dim according how low they are set. I have found, while driving though a tunnel, that the light will turn off and on from passing under the brightly lit overhead street lamps then into a dark zone.