05 Prius no start no dash

When you open the door if you have the light in the car set to the door position does the light in the car light? While that door is open if you look at the dash is there a little symbol showing the doors open on the dash? Let's start there first because you're measuring 12 volts with your voltmeter or a test light on the battery doesn't really mean much It needs to be load tested by a competent capable person running a very nice battery testing machine like it advance Auto Menards O'Reilly's etc those things are quite expensive and they do a pretty daggum good job just lighting a test light doesn't show you anything it shows you have some voltage but you may have nothing behind the voltage The can bus system in the car needs a solid 12 volts and when the car is ready running it should be between 13 and a half and 14.5 just sitting there that's what the inverter throws at it but it doesn't throw a lot of AH at the battery The thing probably charges it maybe 2.4 amps or something silly but very low compared to a car with an alternator that's getting 50 amps thrown at the battery so until you know you have a 12 volt that's viable you'll have a lot of this kind of funny business turns out a lot of this funny business is caused by poor 12 volt batteries happens all the time It's almost uncanny.

 

Not the map lights the push buttons this is the button you slide to the door position or to the on position or off and do you see the little red light on the dash telling you that your door is open?

 

Check your 12 V battery terminals are clean and tight. Check the connection from the 12 V negative terminal to the car's body is also clean and tight.

 

If you've got decent 12 volt things are lighting up so on You open the door and you don't see the red universal indicator on the dash that says the door or the trunk or something is open then you've probably got the CM monitor issue which is your display You can have a code for it and it be semi working. And you can have no codes and the thing is black. The next thing to do is go back to the battery take the little square plastic panel from below the tail light access open it reach in there with a long 10 mm socket and extension loosen the ground wire while you have the hatch open all your doors closed and the car is off now move the ground around until you see the red icon pop up on the dash indicating your hatch is open now lock down the ground go around and open the door get in the car put your foot on the brick I guarantee you you will have a zero on the display in your display lights up your gas gauge and transmission are showing. That's going out because the capacitor's on the board allow something to go to sleep and not reawaken so you need to have the capacitors on that board dealt with by somebody that knows what they're doing predominantly that's this place called Texas hybrids once you get that sorted out other things may start to work properly again directly That's what happened in the '07 silver car that we have when the CM monitor was out since it's replacement from Texas hybrids it has been spot on never a problem and everything in the car works and there's not a light on on the dash ever