2007, 150,000+ Miles. I was having what I believed to be a 12v battery problem, and the battery was in fact bad, but when I replaced it, I experienced the same problem — no dashboard activity with the first push of the power button (except green light on power button), and upon applying the brake and pushing the power button a second time, I hear some of the appropriate noises, but all I see is a check engine light. In fact, no lights whatsoever...headlights, tail lights...nada. I moved the car to its current parking place fewer than 7 days ago (meaning that it started and drove just fine). I have reset the battery, but that didn’t do anything. I have swapped out suspect fuses, but nothing. The hybrid battery was replaced a couple of years ago and has maybe a few thousand miles on it. I’m about ready to throw in the towel. Appreciate any constructive advice you might have.
Welcome to PriusChat!! Have you checked the 12v battery voltage lately? Which fuses have you already checked? Do you have access to a prius compatible ODB2 code reader?
Welcome, Dave. I'd double check that new 12V battery. They often sit on a shelf for a long time before getting sold, so if they or you didn't charge it up before you installed it, it could just be low. Also, I've never tried this: What happens if you do a normal power up? IE, the car is off, and you hold the brake and press the power button rather than hit the power button, hold the brake, and hit power again?
Jerry, Thanks so much for responding and sorry for the delay. I’ve been out of town. I haven’t checked the new 12v to see if it actually has juice. I will do that. Fuses checked include all of what seems to be the relevant 7.5 A fuses. I don’t have an ODB2 reader available, but could call a mobile mechanic if the battery turns out to have juice. And I tried your power up from off as you detailed and no luck. Double checked the battery today. It’s fine.
I think you're stuck without reading the codes. Make sure the code reader is Prius fluent. Many will not give you details of the hybrid system. I recommend at least getting a reader and then installing either Torque Pro (Android) or Engine Link (iOS) on your phone along with the special DTC codes you can find here on PC. Better yet is one of the Mini VCI readers with Techstream if you have an old Windows laptop.
UPDATE: Had a mobile mechanic stop by to run a diagnosis on the car. The errors he got back were all of the “failure to communicate” variety. I’m addition to what is shown as the code reads below, there was a “throttle actuator control” problem and an ECM error. I’m presuming the beast is dead, but if anyone has any thoughts they would be much appreciated. Thanks, David
Hmmmm.... Mice in the wiring? Modern cars use rodent food for wire insulation. It can be disastrous. Or sometimes an easy fix if it's just in one place and you can see it.
Big Dave, Do you have an update as to what happened? I've had the same problem but in checking the battery and wires into the top piece on the battery, I found that some wires have current flowing through and some don't. I have tried to jump it and nothing happened. The battery is brand new and has a full charge, so I'm pretty sure that's not the problem. Does anyone know how easy it is to replace the wires that connect to the 12v battery? I think that's the problem and don't want to pay the high prices of the dealership.