Day/Night mode button gone adjust wheel makes no difference 2006 Prius

Hey Folks

A long time ago during a rain storm, wife complained about not being able to see MPH display clearly.
I opened the manual and it said... go to DISPLAY screen. With headlights ON.. push DAY MODE button.
That worked well. BUT ever since then NO DAY MODE button is ever visible, day or night.
I have turned headlights on and tried adjusting the dimmer wheel..NO effect.
In the manual I found this::


Depending on the position of the headlightswitch, the screen changes to theday mode or night mode.To display the screen in the day mode even with the headlight switch on, touch “DAY MODE” on the adjustment screen forbrightness and contrast control.However, if the km/h or MPH button is on,mode switching cannot be done. It remainsin the day mode. In this case, “DAYMODE” is not shown on the screen.If the screen is set in the day mode withthe headlight switch turned to on, this condition is memorized in the system even with the hybrid system turned off.


HOW DO I RESET THIS ?????

Thanks
Terry Kelsey

 

Hey Steve

Thanks for replying!
I read the entire thread you gave me. Then I waited until it got dark here (8PM).
I tried rotating the adjusting wheel min- max, no change with headlights and tail lights on.
The map always has the bright white background now.
The manual said the info was stored in MEMORY somewhere???
I would really like to know how to undo that setting.

Thanks
Terry Kelsey

 

Hi ex-student

Last night I disconnected the 12 volt battery all night, NO CHANGE.
That does make sense that it is in ROM.
I just called our local dealer and the Service department has no idea how to change that setting back.
As to why it was done, my wife is a very strong willed person and she had seen something in the owners manual about it previously. That's why that occurred.
Stands to reason that there should be a way to switch that back again.
That's why I posted on here. I have always gotten good advice here.

Thanks Again
Terry Kelsey

 

My wife reminded me that when this originally occurred we had just had the Brake light switch on the brake pedal replaced (not starting issue then). She is wondering if the mechanic pulled the wire harness connector off the dimmer switch???? hmmmmmmm
I wonder how big a deal it is to check that??

 

I'm not sure if there would be no lights or max dash lights????

 

I squeezed in under the dashboard, with a small flashlight.
The fuse box and other brackets were in the way. I couldn't see the dimmer switch connector....sigh...

 

FIXED!!

Dimmer connector was not connected. 5 minute fix. Works GREAT!

Terry Kelsey

 

This is how I did it

I watched a couple UTUBES and found 1 screw bottom center.
I removed that screw and lower level of dash was loose.
I pulled it lightly and it came unclipped.
On the left side there is another screw..remove that.
Then I lifted the left side vent from the bottom and it came right out.
I reached in the vent hole and I felt the back of the switch.. no connector.
With my hand still in the vent hole...I easily pushed the switch out of the dash.
I used a small flashlight to find the WHITE connector, I plugged it in and then reinserted the dimmer in the dash.
Reversed the process and put dash back together with the 2 screws.

I hope that helps

Terry Kelsey