New Prius owner - Question on P3009/P3000

An intermittent problem by its very nature can not be predicted but will return following Murphy's Law . . . at a time most expensive or inconvenient. Past reports suggest a small, electrolyte leak of the KOH from one or more modules can respond to high-humidity conditions and induce the P3009. So you have options:

1. Clear and run until it fails hard - sad to say, there have been a few, two that I know of, traction battery shorts that turned into fires. Because of the fires, no knows if the P3009, a resistance path to ground, was part of the mechanism. Also, over time it can lead to unbalanced modules and a different code. (Cheap and fast.)
2. Inspect and/or clean traction battery - it weights about 90 lbs and you need a work bench. Order replacement buss bars; pull the traction battery; remove cover and inspect; remove old buss bars and clean modules; equalize charge; install new buss bars (unless you want to try an clean old ones without breaking the voltage sense wires or repairing); put cover back on carefully, and; reinstall traction battery. (Good and cheap.)
3. Upgrade battery - using known, high reputation battery rebuilders who match improved modules from salvaged 2004+ Prius and swap pack. (Fast and good.)

Good, fast, cheap: pick two.

Good luck!
Bob Wilson

 

Let me suggest you scan the stickies but at a minimum:

• Plan on a Prius aware scanner - they come in various price and capabilities but at a minimum, you need to read the big three ECUs: engine, hybrid vehicle, and battery. Not only the EPA mandated primary codes but the sub-codes of the hybrid vehicle electronic control unit (HV ECU). The battery ECU provides the 19 module voltages which is key if you are going to look at the real health. The four battery temperatures will also help you learn how to drive the car to maximize remaining life . . . heat is the enemy!
• Plan on a shop manual - available new, used, or by subscription, there are three primary or four volumes if you include the body manual:
  1. Volume 1 - diagnostic
  2. Volume 2 - repair
  3. Schematics - tracing wire
  4. Body (?) - for accident repair, often has better parts callout

The folks here are pretty clever and you'll find a lot of good, solid advice. But it helps if you'll visit from time-to-time and share your progress.

I never considered cars very interesting but the Prius is 'a thinking mans' car and it has become a 'hobby.' No, I don't have any interest in going to car shows but I've put nearly 10,000 miles on our 2003 Prius to learn more and the hours . . . it is a hobby.

Welcome to the Prius Car Club!

Bob Wilson

 

Re: upgrading or rebuilding yourself (you probably don't want to do this), Failed traction (HV) battery, what to do? - Prius Wiki might help. Sure hope the OP got a good deal on it, as I wouldn't be buying a used Gen 1 Prius.

 

i'm on my 22nd or 23rd gen. 1 prius. all of which have been state owned and purchased from auctions here in the north-east (...and yes, very harsh winters here) i only buy cars with mileage under 75k. one of things i always PLAN on is that the car WILL need a rebuilt or salvage HV Battery. (however, i've had some good hv batteries as well) after purchasing HV Batteries from salvage yards for $800-1000 i've learned to rebuild w/ gen. 2 modules and it costs me $200-400 after i sell my left over parts.

98% of the time after i install the re-built battery, clean the throttle body and MAF sensor, the car runs and drives fine with no codes. i've never had one customer call me back complaining that their HV Battery died or that they experience any issues. (2 times someone called because the valve on top of the catalytic convertor was frozen, a $20.00 fix)

for the other 2% of the time well... i finally got one last week with a p3120 code (transaxle malfunction) and boy how i wish it was an HV Battery failure. yikes!

OVERALL i think GEN. 1's are GOOD CARS. i'm still driving my 01' w/ 65k miles with a rebuild battery with NO PROBLEMS whatsoever.

 

I think I must be one of the biggest proponents of Gen I's. I love my Gen I (a green 2001 w/ 117k on the original battery).

Here's my advice to the OP:
Take Bob's advise and select option 1 (for now) until you get a hard, consistent fault. In the meantime, set up a plan that accounts for the day that this will happen.