Warning Light to Take Immediately into the Dealer

1. My guess is that your friend made the car IG-ON, where all of the instrument panel warning lights are on. That will quickly drain the 12V battery, probably within an hour or so if the battery is marginal to begin with.

2. The 12V battery is located under the hatch floor, in the right-rear corner.

3. Try driving the car around the block. If the engine runs when you depress the accelerator pedal and you don't notice driveability issues, then you can probably make the 15 mile journey.

4. Check the inverter coolant reservoir for fluid turbulence when the Prius is READY. If you see this then the inverter coolant pump is working. If you don't see any turbulence then this is probably why the warning lights are on.

5. If you have access to a 12V battery charger then I suggest that you charge the 12V battery overnight, at a charging rate of 4A or less.

 

I think your 12V battery is wrecked. The engine does not charge the 12V battery -- the high voltage system does.

What you just described, though, is an electric motor in the hybrid transaxle failing to start the engine. Even though it sounds like the motor is running for 5-10 seconds, if the computers do not detect ignition, then the HV ECU will terminate the attempt to start the engine and set a trouble code.

Still, it is almost guaranteed that your 12V battery is bad. There is all kinds of weird stuff that can happen in that case. Start with replacing the battery, which will clear the trouble codes in the process, and see what happens.

 

I'd keep an eye on your 12v from now on. In fact, if it is the original 12v battery I would be inclined to have it replaced. The 12v in a Prius isn't as strong as in a normal car - it doesn't need to be as it hasn't got to power a starter motor, but just power up the computer which then uses then uses the big High Voltage battery to start the Prius.

It appears they have a life of about 4-5 years and can start to cause all sorts of weird things to happen when they fail. Yours was probably on its last legs before your neighbour ran it down, finishing it off. Not an expensive replacement.

(oh be very careful about jump starting a Prius - see other threads on this!)

 

They're about £150 in the UK including our 20% tax so should be much cheaper in the US. It's a smaller size than usual and I believe an alternative can be purchased but needs to an adaptor for the terminals. Depends how much you want to save and how much the dealer wants to charge. I personally would stick with Toyota unless the non Toyota part is significantly cheaper.

When a 12v starts to fail it'll only get worse - and quickly. Charging it will help get the car going for a day or two but you'll then have to charge it again. This applies to any car, not just a Prius.

 

Many Priuschat.com folks, including me, have installed the Optima D51 battery to replace the original Toyota 12-volt. It will not void your warranty to use an aftermarket part. There is a bit of modification that you will need to do to the car, but it is pretty simple and anyone who is competent with hand tools can do it. I am not one of those, however, so I took it to my trusted mechanic and he was able to do it with little difficulty.

This company referenced below sells the battery with an installation kit for the Prius. I think it cost me about $180, including shipping. Service was quick and efficient. I would use this company again with no hesitation. Good luck.

Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 10

 

I'll quickly add - the problem might not be just the 12v failing. BUT they do cause issues when they start to fail and immediately having issues after the old 12v was run flat probably indicates the 12v.

If nothing else, you'd probably need one soon and it's a cheap fix IF it is the 12v. If it's something else, then you'd have still needed a new 12v sooner than later anyhow.

Let us all know how you get on. Always good to get feedback on whether the problem is resolved or not.

 

There have been many, many threads on the subject:

http://priuschat.com/forums/gen-ii-...ooting/61243-replaced-12v-battery-optima.html

The thread below references the Seattle area:

http://priuschat.com/forums/gen-ii-...ry-why-elearnaid-seattle-area-installers.html

Here is a very nicely done tutorial on how to install the Optima battery. DIY with this as a guide or hand it to your mechanic:

Prius 12V swap

 

I assume you mean the inverter coolant pump. Its the pump that circulates the coolant to cool the inverter and causes the turbulence you see in the pink fluid in the reservoir. If it was wintertime you might be able to drive to the dealer, but having it towed is certainly safer. The car is designed to protect the inverter by shutting it down before it overheats, but some threads here on Priuschat have described inverter damage by driving with the pump not working. As its (the inverter) a very expensive part I'd have it towed and repaired, unless you want to replace it yourself.

Water pump is a very ambiguous term when referring to Prius, since unlike a conventional vehicle, there are four of them on the Generation 2 car. The inverter cooling pump, the main water pump on the engine, the canister pump that pumps engine coolant into the canister after shutoff, and a pump that circulated coolant through the heater core when the car is running but the engine is stopped.

 

That's with the car OFF, right? If the car was running the reading says little or nothing about the health of the battery.

If there is any uncertainty about it, then yes, have it towed.

There is no known aftermarket drop-in replacement for the 12V battery. All substitutes require adapters for any or all of the terminals, mounting bracket, and vent tube. If the battery is dead the easy solution is to have a dealer replace it. $200 would be very reasonable.

Next time be certain that if anyone wants to use accessories for more than a minute the car should be fully ON ("Ready") and in Park, with the parking brake set .

 

1. IG-ON is reached by starting from IG-OFF, and pressing the POWER button 2x without depressing the brake pedal. ACC-ON is reached by starting from IG-OFF and pressing the POWER button once, without depressing the brake pedal. The latter mode is what should be used if an occupant wishes to listen to the radio while the car is not being driven.

2. The inverter coolant pump is located behind the driver's side headlight assembly. It has a couple of coolant hoses attached to it.

3. Yes, there is only one 12V battery in the Prius.

4. Since you don't currently have any warning lights on, then the problem is not serious. It would be a good idea to charge the 12V battery overnight so that you can see whether the battery can be restored to good health. Otherwise, replace it before the car refuses to start.

The inverter coolant pump is supposed to run at all times when the Prius is either IG-ON or READY. I hope that you are looking at the inverter coolant reservoir which is mounted on the side of the inverter, near the engine.

It depends upon how hot the ambient temps are. I believe that the high temps in your area are currently in the mid-60s F. Hence I think it would be OK to drive the car 15 miles especially if you leave the air conditioning off, which reduces the electrical load (and hence the heat buildup) on the inverter. If you want to be sure, you could buy a bag of ice and place it on top of the inverter to help keep it cool.

 

last question? that should have been your 1st lesson.

1st.. if you ever want to leave anything on, leave the whole car on in Ready (brake + power button.) idle radio listening with mild climate control only burns a gallon every 8 to 12 hours. (i won't say "radio only" because a random friend can put the car in ready.. but may not know the full functions of the climate control.)

2rd.. if you wish to leave the car on and unattended for whatever reason (i did this a lot during deliveries) roll down the drivers window, get out, close the door, reach in, lock it, auto roll up the window. keep your key on you as you HAVE to use the mechanical key to get back in.

also... change your 12v battery. it may only last another year or two, and once it starts to die, it makes the car very unresponsive to opening and such. it's cheaper than getting frustrated and having it towed to the dealer to get a new 12v anyway.

 

I like this and am going to try it today. What a fabulous way of keeping the a/c on with the car locked up when popping to the shops.

(if it doesn't work the recovery bill is in the post! )