need help with my prius

Good point Bob, but the OP stated that he charged the 12V. But never verified the actual readind.

 

All very true. The OP states that he bought the car used. Possibly the 12V was never changed. Possibly the HV system is shot. If his HV battery is shot he may very likely be eligible for a brand new HV battery, FREE. Up until this point in time he may not know this. I still suspect his aux battery tho.

 

I missed that it only had 56K miles. The pessimist in me sees Gen I and immediately thinks expired warranty. What are the warranty terms for a 2001, assuming that it is a California car?

 

On mine it is 150000 miles, I'm not sure of the time, 10 years I think...... for the 2001 it may be the same, if he doesn't delay.:rockon: Being in Socal, I assume it was bought in CA, or registered in CA, should qualify. It is great that the warranty is transferable to the new owner. Strange that he was not informed.

 

Classic Prius sold in the US has an 8 year / 100K mile hybrid system warranty. The longer hybrid warranty in CA (and like-minded states) started with the 2004 model year because 2G was certified AT-PZEV.

 

Thankyou Pat, I can never keep that straight.

 

Thankyou Pat, I can never keep that straight.

 

I think you are missing the big picture:

• 12 V system - this powers the lights, displays and all control computers. It is separate from the traction battery but charged from a DC-to-DC converter in the inverter. If your car is running, the 12 V comes from the DC-to-DC converter so disconnecting the 12 V battery has no effect.
• traction battery - this is a 270 V power system that can provide with the engine the "hybrid" in hybrid electric.

If you still have errors on the car, to reset the error codes and find out if they come back:

1. Turn off the car - remove the key. You want it in "P" and not in any way shape or form running.
2. Disconnect the 12 V. battery negative from ground - this will remove the 12 V voltage that keeps the control computer memory alive. It will also clear any error codes PROVIDED the car is powered off and the key out of the car.
3. Wait 3-5 minutes - this ensures any capacitors or other latent voltages sources are gone.
4. Reconnect the 12 V. battery negative ground - this will allow the control computers to be in 'sustainer' mode. You may see some light sparks as the capacitors in the circuit charge up but this is normal and not always seen.
5. Put the key in the ignition and turn to ACC mode - are there any errors indicated?
6. Turn to IGNITION mode - are there any errors indicated?
7. Turn to START and release - are there any errors indicated?
8. Let car run for ~5 minutes in "P" and look for any error indications.
9. Put car in "D" and drive - are there any errors indicated?

This will let us know if the problem was a 'transient' or permanent. It does not diagnose the problem but let's us understand how severe.

Get a scanner (see the other recent postings) to read out the codes and vehicle values. This is your gold standard for diagnosis of the car.

FYI, you might upgrade your profile to give us an idea of where you live. Sometimes it helps so we can make sure our postings are clear and unambiguous. Also, there are folks on the forum who may live near with tools and resources to help.

Thanks,
Bob Wilson

 

I hope you know that you should remove the orange traction battery interlock as a safety measure, before you remove the traction battery cover.

Once you have the cover off, use a digital multimeter to measure voltage on each of the 38 modules. Log your measurements. You'll probably find a couple of modules whose voltage is much below the others; those are the failed modules.

 

I see you are really into it now, there are several threads on attacking the HV battery, replacing battery modules, replacing whole battery pack, replacing with a Gen I or Gen II pack, and lastly balancing individual modules. It would be well worth your while to relax one evening read these threads. Best sources are Bob Wilson, Pat and Vincent and of course Hobbitt. You can search by subject or click on a name. There are others who have also contributed to our knowledge. Working out on a parking spot will interfere a bit with order, if you can you may want to investigate the pack at your apartment.:cheer2:

 

At minimum, you will need to replace the module that has the low voltage measurement, if you can buy a replacement. That should be considered a short-term fix, if you can get the replaced module to work.

A longer-term fix is to replace the entire traction battery but of course that will cost into four-digits.

 

Patrick is right so your options:

• Ebay kludge the modules - the problem is you don't know the Ahr capacity of the modules bought nor the Ahr capacity of the existing modules. User "oldnoah" did the job right but he had the option of the original failed battery and the replacement. Risky!
• Rebuild using NHW11 modules - follow the "oldnoah" threads and think about the time and effort it took. As for the tools, especially the MRC 989, you could PM him to see what he might sell them for. This approach requires a lot of time, 20-40 hours; a good work area; and careful attention to detail. Reduces risk and leads to a quality product. You'll need high technical skills.
• Rebuild using NHW20 modules - instead of buying NHW11 modules (or a 'pig in poke' pack), buy two salvage, NHW20 packs and then follow "oldnoah" processes . . . Done right, a quality product. Requires high technical skills.
• Buy Re-InVolt - ~$1,700, the pack is already rebuilt from tested modules and improved internal wiring. Two people in four hours can swap the pack and you're on the road again.
• Toyota self-build option - ~$2,400, you get a fully populated case of modules and move the electronics over. Then install and run.
• Toyota total option - battery plus labor, easily ~$3,000.

GOOD LUCK!

Bob Wilson

 

I doubt that the one module will recover. It is likely that one cell within that module has shorted, this is why the voltage is so low.

Bob has done a good job of summarizing the various alternatives. Note that you may be able to purchase a new traction battery for ~$1,750 plus shipping. See for example:
Champion ToyotaWorld

and look up the price for G9510-47020.

If you do not fix the traction battery, eventually the car will get to the point where it will not start (since the traction battery spins MG1 to start the engine.) Good luck.