Power loss & hybrid warning light

my red 04 prius had that sensor fail on it twice. both times they repaired it under warranty. My husband's white 04 - similar mileage, no problems.

We replaced the red (totalled) with an 08. I am hoping never to see that problem again.

 

What is the odometer reading on your vehicle?

Is your 12V auxiliary battery the original battery; or was it replaced five months ago after your second problem occurred? If the battery has not been recently replaced, I suggest that you replace it now.

If your Toyota dealer is not able to retrieve any DTC, they won't be able to do much for you. However, if the check engine light came on or the MFD showed a hybrid vehicle warning icon, then DTC should have been logged.

 

Since you have 75K miles on the car, it sounds like it is regularly driven. Hopefully the 12V battery, being relatively new, remains in good condition.

The multifunction display (MFD) is the video display in the center of the dashboard that shows the fuel consumption multi-bar chart and the display with the power flow diagram along with the wheels/tires turning, the battery SOC gauge, etc.

The master warning light is the red triangle that you saw. That light by itself does not necessarily mean that any DTC (diagnostic trouble codes) were logged.

However if the check engine light (the amber light that looks like a little engine) or the hybrid vehicle icon in the MFD (the vehicle with the exclamation point) came on, then one or more DTC should have been logged.

Yes, you might have an intermittent connection. It's hard to know where to look without a DTC to help guide the search.

Perhaps another dealer might have more success in retrieving the DTC?

Are any warning lights on now?

 

As the subject is a 2001 Prius, I would like the consider the possibility of an accelerator pedal problem. Bob Wilson (a poster here) is now rebuilding these.

The DTC for this is posted elsewhere, but it does not alway show up when the engine 'loses power".

 

Out of nowhere, I was unable to turn on my 2004 Prius last night. All I saw was the yellow check engine light, and that was fading. With repeated pressing of the on button, the dash lit up for a minute or so, but I never saw the "ready" indicator. I jumped the battery and noticed that the hybrid battery was almost full in the display. I was then able to drive the car.

Today, I was able to turn on the car (but not initially). The red triangle appeared, along with the hybrid vehicle icon (with exclamation point). When I turned the car off, the navigation screen remained lit, and the parking indicator was flashing. Other indicators remained off, but the lights were dim in the car. It seems there is something electrical that is malfunctioning.

I plan to take it to the dealer tomorrow. The odometer is at 35,000. Any suggestions are certainly welcome.

 

Hi Jan,

I think that your problem is simple: you need a new 12V auxiliary battery. The dealer will charge you ~$150 for the battery plus labor time to install.

 

Thanks, Patrick-

I've never replaced that battery. Should I try to install one myself, if you think I can? Or is it best to bring it to the dealer?

Jan

 

Hi Jan,

If you have experience replacing other auto batteries, then the Prius battery replacement should be relatively easy. I suggest you remove the triangle-shaped hatch floor piece located at the right rear of the hatch area to satisfy yourself that you can (or can't) do the job yourself.

I suggest that you purchase only the correct Toyota battery if you are a novice at this. Please make sure that the battery terminal polarity is correct (when facing the battery with the terminal side closest to you, the positive terminal should be on the left.)

 

Patrick-

Um, I think I'm having the dealer do it...Thanks for your confidence in me. My nursing skills may not cut it here!

Jan, RN

 

I read that in the '04 to '05 model year there were a few vehicles that experienced the exact same proble you're experiencing. Toyota found the cause and fixed it: a bug in the software. It appears you haven't had that corrected yet. So, I wished I could help you more, but a little research should solve it for you. My guess is you're going to need a new engine control module or a new software flash.

 

Hi Jan,

OK. It appears that you have the ability to jump the Prius. That being the case, you may wish to do so again (if the car won't start on its own) then leave the car READY (and in P, or in D if driving) for at least one hour to allow the 12V battery to charge up (not necessary to actually drive the car during this period).

Then see if the battery holds a charge or not. If not, then a new battery definitely is in order.

 

Patrick-

What do these batteries cost?

 

Hobbit has a base model Prius, so the battery shown on his website is smaller than the battery used for vehicles equipped with SE/SS. The latter battery has a black case, not translucent, and is longer. Same height and depth.

Classic has the same size battery as the base 2G, but with reversed terminal polarity.