Won't shift into drive or reverse, pops back into neutral?

could be a bad shifter, or 12 volt battery. you need a garage with the proper code reader for a prius.

 

The dashboard lights cannot be used to correctly diagnose what is wrong with your car.

The best money any Prius owner can spend is on a Mini VCI cable. They are available on Amazon or eBay for less than $25. The Mini VCI cable and Toyota's TechStream software will let you diagnose your car on your own. You will need a windows laptop to use the MIni VCI cable and Toyota Teachstream.

Try disconnecting your 12 volt battery and then reconnect it after a minute or so. This will clear many codes. It will not fix the problem, but you might get your car to run correctly one time before shutting it off.

Brad

 

It will run on his Mac if he loads Windows (XP or 7 32 bit) either as a "Dual Boot" or in a virtual Windows window.

JeffD

 

not to harp on it, but are you aware of the idiosyncrasies of the prius 12v battery?

 

I wouldn't be too sure of that. Your symptoms (as already pointed out) sound like a bad 12v system or heat. The possible causes are a bad 12v battery, bad inverter, or a hot inverter.

It sounds like the key fob battery may be going low, it doesn't matter. If it is blocked by a cell phone, wallet, seat belt buckle, whatever, the car can lose the fob signal. After you READY the car, you can throw the key into the ocean and drive for a decade as long as you never press that power button to turn it off. It is a safety issue. You don't want to be driving down the road, you shift in your seat, it loses reception and the car screeches to a halt.

Did you see if this Prius had the recall work done to the inverter coolant pump? Have you checked for fluid movement in the reservoir? After sitting for a while did it come back to life?

It sounds like you don't trust your dealership, and if so, then why is it there... Most shops have no idea how to work on such a complex car as a Prius. And when you the customer tell them how to do their job by replacing "the starter battery" they just say that's not the problem and move on not even knowing what role the 12v plays in the car and what actually turns over the engine.

My Nissan dealership is still sending me emails and snail mail and cell calls telling me I am overdue for an oil change... on my pure electric leaf that doesn't have an engine! They sell this car, and yet when I try to explain that it doesn't take oil, I get talked to like I am the idiot and I just don't realize that all cars have engines and need to have the oil changed every so often.

 

Good that it was fixed, might still want to double check. Since the problem persists after long "cool down" periods, I would say this scenario is much less likely however who knows how hard the previous owner hit the inverter? I would make this a very low priority, it doesn't sound like inverter overheating is the problem at this point.

More explanation needed here. The car was off. You attempted to READY it (foot on brake and press power), and then what exactly happened?

Did the READY light ever, even if briefly, flicker on to show READY on the dash?

As you press the brake pedal, you should hear a pump start priming the brakes. This will happen with the car "off". Then you press the power button, and you will hear 3 clicks (really 4, 3 engaging loud, 1 disengaging, hard to hear if at all) from the back of the car, which are the main HV power relays turning on with the current limiter and then for full duty. On a normal start with a normal traction pack SOC, the car will turn READY and then 7 seconds later the gas engine will attempt to be started. MG1 will steal power from the traction high voltage pack to spin the engine up without any fuel to get it up to speed. Then fuel will be injected, fire, and hopefully the engine will start spinning under dinosaur power. This will continue until the engine and coolant system has reach standard operating temperature (Stage 4 warmup) and the battery is charged to or above 3-bars on the display. If the battery is down to 1-bar on the display, the engine could have attempted to be started immediately instead of after a 7 second delay, but the rest should remain the same.

If your 12v battery is SUPER DEAD (~9v) it cannot flip the main HV power relays. The car will do nothing. It might still make some gurgle sounds on the brake pump, but you won't get any relay clicks and the car will remain dead.

If your 12v battery is DEAD, then it may flip those relays and then the traction pack is part of the circuit. The car will then attempt to draw power from the 12v aux battery to power up the various ECUs and get the inverter ready to turn on. If the battery is weak, not all systems will turn on properly. If any one component fails its internal startup test, or fails to communicate on the network properly, the car is automatically prevented from becoming READY in drive for safety reasons and the dashboard lights up like a Christmas tree.

If all goes well, and the inverter turns on, you will see the 12v power bus increase in voltage and now the car is running off of the HV traction battery pack until it gets shut off with a power button press.

These 3 states are very easy to see with a DMM. With the car off and sitting all night, you should measure 12.4 or so volts on the battery. Press the brakes, and it should dip momentarily, never below 11v. Might be too fast to see on crappy DMMs. Press the power button and the battery will most likely droop to 12v or so but never below 11v. After a period of a few seconds, sometimes right before the engine turns on, the voltage should jump to 13.8v or 14.4v which is the signal that the inverter has regained consciousness from its slumber and is now powering the car via the traction battery and re-charging the little 12v battery. That 13.8v or 14.4v should remain very constant for a long time no matter if the engine is off or on, lights are off or on, defrost, whatever, it is now being charged rather than discharged. If you measure less than 11v at any point, your battery is completely dead. If you measure 12v or lower after resting, your battery is completely dead. If after a long time you do not see a 13.8-14.4v level on the line, then there is a fault somewhere between the traction battery and aux battery (battery itself, main HV safety relay, inverter itself, main 100A fusible link, and then the big red connector on the aux battery itself).

If you are here, then the aux battery is good and the inverter is online. The car will then draw from the traction pack to spin MG1 you will hear (and see) the engine spinning but there will be no fuel flowing. Then you should hear detonation and the engine start. If the traction pack is lower than about 10% to 12% then MG1 will not be successful in maintaining engine RPMs to start the car. There is no "starter" run off of the 12v battery, is a giant electric motor pulling off of the high voltage pack. The only solution is to grid-charge the pack which means either flying in one of the very few and rare genuine Toyota grid-chargers for the Prius, or there is now a solution on the PriusChat.com store meant for DIY'ers to preventatively charge up the pack. Either way, you need to get wall juice into the battery so it has enough to start the engine. It is a chicken and egg problem. Without pack power, the engine can't start. Without the engine started. the pack can't be recharged... That's why when the battery gets to around 40%, it shows 1-bar on the screen and will always recharge it. The only way for the pack to be discharged like this is to drive it when out of gas, or to continually try to start it when it will not start. That will take it from some large SOC value lower and lower with each attempt until eventually it is so low it will never work. You have done a lot of starting... You may want to verify the pack voltage with an OBDII scanner.

Assuming the HV pack is charged enough, there could be a short in MG1 (rare in anything but Gen1 Prius), could be no fuel, could be bad spark plugs, bad fuel, and numerous other "normal car" problems that any good mechanic worth their salt should know. The complication is that they only get a limited number of guesses to start the car before it becomes a brick and you have to grid charge the HV pack. So hopefully it is a good mechanic and not just "winging it".

If you ran out of fuel as you were driving the symptoms would also be similar to what you describe. Just checking the obvious, is there gas? Not what the guess gauge says, they can break too and even when functioning optimally, they are many gallons wrong in our variably sized fuel bladders.

Two weeks isn't a problem. There have been reports of sitting for 2 years and only losing a couple bars of SOC. The cells will be imbalanced, but the pack will still be OK if reconditioned gently after reviving it.

That is common and generic warning message that means it is READY and not in PARK but one of the doors is open. That's all that scary and cryptic message means. My guess is that a door was open, it is in a shop anyways.

If you replaced the 12v, it is already "reset" assuming you took more than 30 seconds to replace it.

Yes it is possible it is the spark plugs. My plugs were replaced (by me) at 130K miles and they looked brand spanking new. Ok not quite, but they had years of life left in them. I replaced them with some good plugs since they were due. I recently remember seeing a picture of OE plugs on a car with 290K miles that looked pretty bad, but still functional. The Prius is very resilient.

 

see straw brads post #3, until you read the codes, it's going to be whack a mole 24/7.

 

You've got to measure the 12V battery. Everything so far sounds like it is the problem. It wouldn't be the first replacement battery be sold in a discharged state. Maybe there is a problem in the charging circuit, in which case even a good battery would just go lower and lower.

 

I have having similar problems with my 2005 Prius but this seems to be happening after I got a P0A80 code (bad battery). I have rebuilt the HV battery and re-installed it about 4 times trying to get it to work. I keep pulling it out to re-check everything to make sure I am doing it right and spent a few days trying everything suggested in other forums, but after reading your long, detailed, and thankfully clear step-by-step I am starting to think my problem now lies elsewhere than the HV Battery. I have had a little trouble keeping the 12V charged as all of this work and testing drains it, but it keeps above 11V for everything.

I tried connecting my multimeter to the 12V and ran it to the front seat so I could read it while I tried starting the Prius. It dipped when I press brake and pushed power. My display lit up with all the same warning lights as ever. I did not hear the distinctive clicks (3-4) that usually are there. Obviously no gas engine kicked on. When I try to engage Drive or Reverse the display flickers and resets back to neutral and the car does not acknowledge any gear engagement and remains still. The multimeter did NOT show any spike in voltage. It stayed at just below 12V and held steady for about 2 minutes. I then powered the car off. A few minutes (maybe 4-6) later I did hear the little raspy motor kick in under the hood for a few seconds.

So I am thinking trouble with the inverter or hopefully just the relay, but I have not been able to identify the location of the relevant relays to test them. I would appreciate some sage advice directed at the testing steps necessary to isolate the problem now that it seems to have moved under the hood rather than in the rear battery areas.

Dax

 

welcome! sounds like your 12 volt is bad to me. how many miles on her?

 

Just re-lifing this thread, for those interested and looking for a solution like I was. Found the 12 volt battery in circuit was 10.6v and isolated was 11.6v - first battery replacement in 12 years and 403000kms - not bad. Had the same problems with 5 yellow dash lights, 2 red and the red indicator on the main screen. The battery (OEM) was $314AUD. Crazy! Understanding it's a different type of battery, my first replacement, and to get an Optima Gel option wasn't possible within the week made it worth it. Had to fit it inside the car as it was pouring - the missus thought I was rained on but it was sweat.

Pulling the old battery out I noticed moisture on the side where it is vented. I thought this unusual.