Another Prius Down

First, thank you to everyone here on PriusChat. I've learned alot and i've been scraping the pages here for the past month, along with youtube. That's about how long my car has been down.

I purchased my 2007 Prius about around april of 2018, as is from a used car dealer.

It drove great. I drove it fast sometimes. And I noticed the battery wasn't lasting as long before it the engine would come on to charge it. Sure enough, the HV battery went out while my wife was driving it. She was able to limp it home and it sat there for a while.

I got the Red triangle along with a bunch of other lights on the dash.
I used the Torque app with a blue generic ELM adapter from amazon to read the codes.
P0A80 - POWERTRAIN
P3022 - POWERTRAIN

From what I was able to scrape from PC and google, I got confirmation that the HV battery had issues. I pulled the hybrid battery and to my surprise, it looked like it had already been rebuilt before this. All the modules had color coding. A friend and I tested all the modules for voltage and we found 5 that were reading 6.5v or lower. I tested them an charged them and sure enough they were no good. I ran a discharge/charge cycle on a few of the suspect modules. I replaced two more modules just to be on the safe side. My charger took a dump on me so that went back to the factory for replacement.

Since the charger is easily 2+ wks out, I can't balance the HV batterypack like i wanted to so I ended up assembling the HV battery back together. I put the V meter on the modules and they each read between 7.2v-7.7v. Once installed it in the car, I cleared the codes, but the car wouldn't start.

I noticed the 12v battery was starting to die out. I took it to the autoparts store to have it checked out. They initially told me it was bad. They put it on the trickle charger. Next day, battery wasn't fully charged but the battery tested good. I bought a charger and let it sit about 6 hours at 2A to charge the 12v battery to 100%. Reinstalled it, checked all my connections and cleared all the codes. The car sat without a 12v battery for 2 days.

Gas was low so I added 5gal of fuel.

Torque still isn't picking up any codes. I still have the red triangle along with a bunch of other lights, and the car wont start.

So I purchased the techstream adapter and I'm waiting to get that in the next day or 2 so I can diagnose it. Anyone have any suggestions on what to look for?

 

Just got back from vacation and I'm back at it. Thanks for the info guys. It's been helpful. Although I'm not out of the woods yet, progress has definitely been made.

1st

Thank you for this TMR-JWAP. This clue was the missing link. I went and looked up a video on what you mentioned and I found this. At the 1 minute mark i was like OMG. That's it.

I went and checked the battery before turning the car on and it read 8.99V. A definitely drop of over 3V in one week. But there was still enough juice to get the car started. It didn't hesitate at all on startup and all the lights and accessories functioned like normal. I'll probably take the battery back out and fully charge it again.

As far as corrosion goes, there is none in the battery tray nor on the battery itself. When I pulled the battery initially, i cleaned the terminals and battery connectors with a wire brush to get the oxidation off.

My 07 Prius has a 110k on her. Still looks great.

Ok so onto the Semi-good news. I pulled a rookie move and didn't push down on the HV safety connector. Once that was in correctly, the car started easily. It's been a solid month since it was last on and the engine sounded a bit rough at first. I let it warm up and charge the battery for a good 5 minutes. The car didn't display any warning lights. So I took it around the block gently never really getting over 20mph.

Just as I was getting ready to complete my first lap, I get a handfull of lights. The Red Triangle, The Exclamation mark, VSC, Check engine, and low tire pressure.

I pulled it into the driveway and plugged in the laptop and ran the health report.
The engine had several misfires which is somewhat unexpected as the engine always ran great. I'll upload screen shots below.

 

Looks like i'm going to have to find an image hosting site as i can't past a link yet to my Google drive for the pics. Anybody have any suggestions for free image hosting sites?


Regarding the DTC codes, I need to look up their meaning, but im getting:
Hybrid Control:
P0A0D (has a cloud) See Below

ABS/VSC/TRAC
C1241(has a cloud) See Below
C1242

TIRE PRESSURE MONITOR
C2121 (This one is easy as I have a nail in the tire.)

Air Conditioner
B1421

Hybrid Control (Cloud)
P0A0D-350 High Voltage System Inter-Lock Circuit High
Out of all of the info, only the following stands out. Not sure if anyone can make heads or tales of this?
+B = 11.93V
Accel Pedal Pos #1 = 16%
Accel Pedal Pos #2 = 31.7%
Throttle Position 14.5%
Detail Code 2 = 350

 

Thanks TMR-JWAP.

I'm going to charge the battery up tomorrow and I'll double check all the connections for corrosion and to make sure they're plugged in all the way.

I think you're talking about these wires here?

 

For anyone interested, I created an album in my profile with pics of the DTC Codes I pulled using TIS.

 

TMR, You were right on the money. Thank you. The Prius is fixed and running. No codes. And it charged the 12v battery almost fully in the time it sat there idling. So yes, There was a loose plug. Not sure which one it was because I went through and disconnected and reconnected all the plugs for the 12v battery and the Hybrid battery.
Thanks a ton.

So this whole repair ended up costing me under $700. That was

7 replacement modules at about $40 each (with Shipping) total $280
A quad charger @ $150
12v AGM Charger @ $70
The newest scantool @ $70
Torque Pro @ $5
A blue OBDII Blutooth dongle at $15.
Some wire, clips, volt meter, tools & Misc items @ $50
And countless soda, beer, internet research, and my own labor.

That was fun and less expensive than a replacement battery.

 

I couldn't have done it without your help, Prius Chat, and youtube. Thanks again everyone..

 

Hello all. I'm back. The car drove well for a little bit and I got some more codes. It appears I have another module(s) in bank 5 that is bad.

Also the engine started giving me issues in the form of hesitation and knocking / misfires. I started by adding some fuel injector cleaner in the tank with a half a tank of premium fuel from Chevron. Normally I put Arco.

Then I changed the spark plugs and cleared the codes.

It ran great for about 20 miles then it gave me some lights and it ran really bad.
I'll upload more info tomorrow.

Anyone have any idea why the engine would start misfiring out of the blue?

 

Ok so im getting the following codes:
P3000 for Hybrid Control
P3022 for HV Battery
C1259 & C1310 for ABS VSC TRAC

And lastly engine and ect monitor shows a misfire rate of 20

 

I know i have an issue with bank 5 of the HV battery so i have modules on order. Im hoping this will fix the other issues because from what ive read the abs vsc trac is all related to the battery. I just cant wrap my head around the misfires. I cleaned the MAF sensor. Its not something i really know hoe to test outside of the car. Im tempted to buy a new one and new spark plug coils but i dont want to just throw money at the problem.

 

Here an update to my prius if anyone's interested. I went throught the entire battery. It took me a solid month and a half of working on the hv battery in my spare time on evenings and weekends.

Part of what took me so long was that I had spotted an issue midway into my testing where the module voltage readings became unreliable because of a cheap volt meter i picked up. After about a week of research on function vs price point, I ended up buying a Fluke 117 multimeter. The accuracy, stability, and repeatability of the readings was very noticeable vs the harbor freight cheapo. This said, I'll never buy another cheap multi-meter again.

 

The learning process and becoming familiar with the modules characteristics was a journey.
I've learned quite a lot in that month and a half of testing, charging, discharging, and logging data.

I've come up with my own system to test and replace faulty modules. The idea was to base which modules to replace based on average charge/discharge characteristics, as well as swelling characteristics.

I used the EV Peak CQ3 quad 100w charger for this.

Basically i made sure all modules where fully charged and had a stabilized voltage. I would then discharge them down.

Then I would capture the time and mAh it took to discharge. I would also capture the voltage the modules would stabilize to 5m after the discharge. I would then charge the modules back up. I would record how many mAh it took to charge the modules and how long it took. Also, I watched for swelling.

One thing I noticed with modules that swell more than approx 1/16" is that you're pushing the batteries either too hard, or they are bad, or both. The modules that swelled up big time were always bad, or going bad.

What I ended up doing was using my charger/discharger to keep track of how much power in mAh was taken from the module and the amount of time it took. This worked in reverse too during the charge cycle. The charger tells you how long it took to go from the discharged voltage to the target charge voltage, and how many mAh of power that battery took.

Modules tell you alot about their condition with this information. I saw modules that took a long time to discharge and charge. Then there are the modules that discharge really quickly. Some regenerate better than others. Etc.

Anyway, i've got 500 miles on the rebuilt battery. So far so good.