2001 prius will not start Help!

[apogeeren]

Help please! 2001 prius will not start not even for a second. The ready light will not come on and the dreaded triangle displays instead. Tried to jump start the battery even though it is good but still nothing. I have searched the posts and looks like it is common for the car to start and die but this will not start. On the display the main battery shows like 20% full and have scanned in generic mode with no dtc's stored. Don't have any ideas of where to go from here? checked gas cap and throttle plate and have 3/8 tank of gas. Afraid, very afraid of the dealer....!

[morpheusx]

no fault codes?? are you sure its not a dead 12v battery, with a dead 12v you could possibly have lost any fault codes.

[bwilson4web]

Originally Posted by apogeeren

. . . Tried to jump start the battery even though it is good but still nothing. . . .

What is the 12 V battery voltage?

A sufficiently bad 12 V battery, two or more bad cells, will not even 'jump' properly.

Bob Wilson

[tochatihu]

Hi new poster. Follow advice above about battery. If you are not measuring the voltage of your battery pair during the process you cannot be sure that the voltage is adequate.

You say you have checked the throttle p[late but I want to know the specifics about that.

If in fact your HV battery is getting low in voltage because of many attempts to spin MG1, there is a need to be cautions here.

Can you give some history here? Did this situation develop suddenly, happen before, or were any precursors observed? Any recent miantenance?

How about telling us about all the major maintenance the vehicle has had?

[apogeeren]

Previous post: If in fact your HV battery is getting low in voltage because of many attempts to spin MG1, there is a need to be cautious here. Give us some history of the vehicle:

Ok after driving this a month or so ago on the highway the triangle light would come on and get a little sluggish so I kept in the city then went out of town for a couple of weeks and now won't start. I checked the battery voltage after I posted earlier and got 12.53 volts @ 68 degrees here in topeka which should be fine. I also used another battery and got virtually same reading. I scanned again for dtc's and got no codes (generic mode). However resetting the codes did wipe out the main battery warning for a second. After resetting maybe 100 times I got it to say ready a couple of times and tried to start it and did everything but start all the other lights came on but the gas engine didn't come on. I put a 19MM on the crank just to rule out motor being locked up. Oil is extra clean in the car and is in good condition except for this problem. I did have some warning but didn't think it would quit altogether.

I am curious I have always thought the 12v battery started the car? So if the main battery is way down the car won't start? I don't have the hybrid warning indicator just the main battery warning. Thanks for your posts!

[Patrick Wong]

Well, now that you've mentioned that the traction battery warning icon is on, that is strong evidence that the battery is bad. And yes, you definitely need the traction battery to be in good shape, or else MG1 will not be able to spin the gasoline engine to start it. The 12V battery's contribution is to power up the ECUs so that the system main relays that switch the traction battery positive and negative leads will turn on.

A generic OBD-II code reader is almost useless for diagnosing hybrid system problems; you'll have to have a Toyota dealer tech scan for DTC using the Toyota diagnostic laptop.

[bwilson4web]

Traction batteries are more affordable now and there is an active market of "used" (buyer beware) from salvage Prius. When (if) you get an estimate for the traction battery, consider it relative to the purchase price of a hybrid versus a new one.

The NHW11 traction battery was improved with the NHW20 (2004-2009) and ZVW30 (2010-current.)

GOOD LUCK!
Bob Wilson

[cygnusx1]

Is replacing the cells feasible for a novice? I have taken the main battery out before but just switched it out... I can get an 05 prius main battery w/ low miles for $500 but is this possible and what is entailed in attempting this?

[tochatihu]

apogeeren, based on all above info, I think this car has to go to a Toyota shop. I hope you can find one you trust in or near Topeka!

cygnusx1, not for novice. One must be skilled in working safely around dangerous voltages. For swapping out cells, you need testing equipment to identify which ones are bad, and to identify those that are most closely matched to build up the replacement set. A rebuild with unmatched cells would likely have a short functional life.

[bwilson4web]

Originally Posted by cygnusx1

Is replacing the cells feasible for a novice? I have taken the main battery out before but just switched it out... I can get an 05 prius main battery w/ low miles for $500 but is this possible and what is entailed in attempting this?

The problem is the NHW20 battery modules are physically, slightly different. It may be possible to repackage 38, NHW20 modules in an NHW11 battery pack. Each NHW20 battery assembly contains 28 modules and two salvage packs are unlikely to have modules in a similar state of capacity. As Doug pointed out, there is a module balancing problem and this is not a trivial problem. I know of two attempts and only one worked.

In engineering we say: good, fast, cheap ... pick two. If you have another vehicle, good and cheap is possible while you work on the pack. But if this is your primary vehicle, I would recommend going with good and fast ... it will cheaper in the long run. But it helps to understand the health of the rest of the vehicle.

Have you been changing your transaxle oil? How about the inverter and engine coolant? These can lead to other expensive repairs. But it also depends upon whether or not you have backup transportation. It is not cheap to own an older car ... the car payments are replaced by unscheduled maintenance.

Bob Wilson