P0B65 engine code

Did you replace with fully charged 12v? I'd start there... And if you made the mistake of buying an Optima 12v, just get your money back and buy a real 12v that's not built by criminal con-artists.

 

That's not an engine code, it's a code about the voltage sensor wiring inside the traction battery (the large, high-voltage one). There are 15 such sensor wires, the − reference and one for each of the 14 pairs of modules (28 modules in the pack). Your P0B65 is telling you the ninth one of those is reading less than 2 volts.

That's a completely unrealistic reading for a pair of 7.2 V NiMH modules, normally more like 14 to 16 V, so a reading < 2 V is not really telling you anything about the modules, it's telling you the voltage sensing connection is kaput.

 

if you're not comfortable, you need to take it to someone who is. corrosion is prius worst enemy, and definitely your problem.
the battery needs to be opened up ans thoroughly inspected and cleaned.
even then, sitting that long might have damaged some modules

 

p0b65_toyota.html

watch

p0b65-obd-ii-trouble-code-hybrid-battery-voltage-sense-i-circuit-low-control-module-solution

 

Umm, out of the three links bisco provided, the only one that says that is the third one (from "Parts Avatar"), and the only reason it says that is because it's wrong.

Wrong for a Prius, that is.

I've posted a few times in other places about the danger of internet searches for trouble code meanings, for codes in the manufacturer-defined ranges, like P1xxx codes. You can get explanations for a code that means some completely different thing in some other car, and be sent on a totally wrong track.

This example is a little different. P0 code meanings are standardized by SAE, so in any kind of car that can give a P0B65 code, the code is going to mean the car is a hybrid or electric, it measures its traction battery voltage in at least 9 places, and the 9th measurement is bogus. So you can safely learn about that much in an online search, as far as it goes. But beyond that you still have to be very careful.

Because that "Parts Avatar" page is trying to cover what P0B65 might mean for any car that can say it, the page has to include things like "battery coolant pump" because some hybrid or electric cars may have one.

A Prius doesn't have one, though. Its battery is air cooled. The other code you have, P0C73, refers to a pump that is under the hood and cools the transmission motor/generators and the power electronics. That pump has nothing to do with cooling the battery, and your P0C73 is not related to your P0B65. It's just a second issue.

You can see here again the kind of red herrings you can run into by looking up your trouble codes any place other than the repair manual. The repair manual for a Prius tells you exactly what each code means in a Prius. Generic online pages covering what the same code might mean across all possible cars won't tell you that.

Ironically, even as SAE standardizes more and more trouble codes, that still doesn't help as much as you might think. In a Gen 1 Prius, an inverter cooling pump issue wouldn't give a P0C73 code, it was P3130 (in the "jointly defined" P3 range), because of course there weren't a lot of SAE standardized codes for hybrid vehicles yet. So you would have to look that code up in a Prius repair manual, and when you did, you would learn exactly what pump that is, and what things it cools, and how it is operated.

Fast forward to Gen 3, and hybrid cars are now enough of a thing for SAE to have standardized a bunch of codes for them, so now there is a P0C73 code (in the SAE-defined, P0 range), and Toyota updates their firmware to give that code instead. Now you can look it up other places online, because it's a standard code.

But as a standard code, now all it means is something like "this car has at least one cooling pump somewhere related to the motor electronics, and the one considered 'pump A' has some kind of issue." To find out the specifics, like what pump this really is and what things it does and doesn't cool, you still have to look in the Prius repair manual.

It could be possible that some other car even has a "motor electronics coolant pump A" that has something to do with cooling the battery. But the one in a Prius does not.

 

How that voltage-sensor module looks on its outside is only skin-deep, but that orange connector on it (and the skinny wires connected there, leading out to every second battery module terminal) are the window into its soul.

(That orange connector also carries well over 200 volts DC if the service plug is in, and still over half that even with the service plug pulled, so is not to be handled without precautions.)

 

That is undoubtedly what a dealer will say, because that "frame wire #2" with the skinny sense wires, which could be ordered as a separate part in earlier generations, is not for sale as an official Toyota part in Gen 3.

So what will happen is the dealer will give you a price, and you will have to think carefully about whether the car is worth putting that kind of money in, and that will be a hard decision.

The only chance I can see to improve on that would be to find a hybrid-qualified independent shop that isn't a dealer (and may have some of those wire harnesses available, salvaged from other batteries), or DIY.

 

how many miles on her? have you done any major repairs?

 

yeah these cars don't like sitting. once you get the battery sorted, look into 'egr circuit cleaning'