No Power whatsoever, for the second time.

Mine started exhibiting similar symptoms this week. No DTCs out of the ScanGauge. The battery is a 2 years old Optima, like our OP CDSK.

1. First time it happened I was able to recover by getting a jump from a neighbor
2. Second time, I was able to mash the Start button repeatedly until it came back to life
3. Third time, I wiggled the clamps attached to the battery in the rear

I'll update if I come up with anything more specific. I'm hoping it's just a loose or corroded clamp. These electrical issues are difficult.

 

Update: Upon closer inspection, I noticed that the clamp attached to the positive (+) terminal was almost completely unbolted, leaving the connector completely loose. I've since tightened it and am hopeful that solved the problem. I'll update if that's not the case.

 

Check the battery's voltage. Cleanest method for doing this, if you can: leave the hood "popped", overnight, and check at the jump start point, without opening any doors. Use a decent quality digital multimeter.

For more in-depth assessment, look into something like Solar BA5.

 

When you guys have this happen, does the brake booster still come on when you hit the brakes? Or the brake light? I have the same issue, not the battery 100% sure, power everywhere in the car on the multimeter but nothing works, can't even turn on headlights or dome lights. BUT the brake booster comes on and brake lights work! Mine has been like this for a week now and I've pretty much disassembled the whole car and am maybe a day or two away from having it scrapped if I don't figure it out! So frustrating. Should have stuck with a regular gas car.

 

So this happened to me this morning, walk out to 07 prius, jump in, hit start button, drive an hour to work, get settled, walk out to car, drive to get a taco, order my tacos to go, get tacos, come out 5 minutes or less, car is completely dead, no lights, no nada, sit there and take key in and out and push button a billion times, start trying to figure out how im gonna get to battery through back seats, unlock pass door from front seat, go around, open pass door, then reach back, unlock rear door, open rear door, see seat belt sign on dash come on, walk around to drivers side, car starts right up?

 

Check tightness of battery cables including the negative cable at the body. If you don’t find a problem, buy a new 12V battery.

 

Pretty sure that's my problem, this morning it did it to me again, car showed no signs of power, then it was kind of showing some signs of power until I hit the brake pedal then it went dead again, checked power battery 6 volts, unhooked positive, battery still had six volts. Pretty sure I just need a new 12 volt battery

 

12v battery was dead, now onto the dash and figure out why i get 32 mpg

 

might improve with a new 12v

 

fuel economy is slightly increasing, might pull plugs and give them a look.

 

Do you reset the average consumption on the consumption screen after every fill up?

If it is not your practice to do this, then reset it now and for the next few tank fills, to see what you tank average is. This is more useful that looking at the instantaneous consumption as you drive.

Also, if you are not in the habit of reseting the average consumption on a regular basis, the average will be displaying for the miles driven since the last time it was reset. So, if that is a long time ago, any improvement that you make to the synergy drive will take a long time to reflect in the average displayed.

For everyone's information, on the 2004-2005 Gen 2, both the miles driven and the average consumption automatically reset when the system detects a fill up; on the 2006-2009 Gen 2, only the miles driven resets automatically when the system detects a fill up. Therefore, on the 2006-2009, the average consumption needs to be reset manually as required.

 

I have the same symptoms with 2007 Prius. On the few occasions where the car lost all power, opening the passenger door has so far restored the 12 v power. Did anyone get any definite solutions as how to fix this situation?

 

How old is your 12v battery?

 

Check the battery connections. Once started, the Prius doesn't really need the 12V since the inverter's DC/DC converter is supplying the necessary 12V power. As the car bounces and rattles over the pavement, loose connections make & break contact. It's likely that you have a loose connection at one of the battery terminals, but I wouldn't rule out a loose ground wire to body connection.

 

Battery is about 2 years old.

 

That makes sense. On closer inspection my +ve battery terminal was slightly loose. I tightened the +ve battery terminal. Cleaned and and retightened the ground connection to the body. Keeping my fingers crossed the car does not loose power again.

 

I desperately need you expertise
Please help !!!! | PriusChat

 

When investigating a bad 12 volt battery always test the voltage at the front jumppoint under the hood. Measure there.

A healthy 12 volt battery in a Prius g2 should be around 12.6 volts at that jumppoint with the car OFF.

anything less than that can be easily tested to see how bad the battery is.

With car OFF measure At the front jump point measure the dc voltage. Then with car OFF turn on the headlights in high beam. With the headlights on in high beam what does the voltage measure at the front jump point?

it should not drop more than a volt in the headlight test. If so depending on how much it drops it may be on life support.

 

It’s a battery proper term is B+.