Battery Energy Control Module

Welcome to PriusChat!!

Was the second hybrid battery replaced with a new OEM by the dealership?

Given the low miles and your location, I would check the HV battery ECU and harness for corrosion, and clean or replace as needed.

Not all OBD2 scanner are hybrid compatible, and may not offer all of the stored OBD2 codes (DTCs) in the computers (ECUs).

Don't know much about the FIXD product, many DIYers will use a 'mini-vci' cable (20 usd) and Techstream (dealership technician software) installed on a windows device. Others may get by with using an OBD2 adapter with an App like Dr Prius or Hybrid Assistant. If going the bluetooth route, be sure to purchase a quality adapter : Hybrid battery diagnostic and repair tool for Toyota and Lexus

Like 911 mentioned, try inspecting your existing ECU and the voltage sense harness for corrosion first, before replacement. Look closely at the socket and connector, and you may want to remove the ECU cover and take a peak inside for green stuff or whiskers as well.

The battery fires at ECU sense connector thread | PriusChat
The battery fires at ECU sense connector thread | Page 5 | PriusChat

Sounds like you have this covered already, and you shouldn't need to physically remove the HV battery to get at the ECU. Besides the videos, here is a step by step guide with images : 2004 – 2009 Toyota Prius Plug-and-Play Car Harness Installation Instructions | Hybrid Automotive

I wouldn't recommend a refurbished HV battery unless I knew the person doing the rebuilding. New OEM can be had for under 2k, then self install. There is also the newpriusbatteries.com option as well for 1600 total, which includes delivery, and again a self install.

Has the HV battery fan ever been cleaned?

FYI : your posts are being moderated until you've posted five (5) times.

 

The pins on the left side of the orange socket look suspect, can you remove the ECU cover and inspect at the motherboard?

You shouldn't need to take out the battery to remove the main cover for inspection, just remove the back seat. That new OEM battery came with new busbars, and a voltage sense harness, but the old ECU was swapped into the new pack, so check inside the ECU first.

How many years ago was the new OEM battery installed?

Do you have any water leaking into the cabin?

 

Check the backside of that socket, where the pins exit the socket, and where the pins enter the PC board. Though hard to tell, the lower right pin in the last picture kind of shows a dark spot on the PC board, if corroded you may just call it dead. Post closeup pics if you can.

If it passes the above visual, try to clean up the pins inside the socket using a tiny strip of emory board, or a piece of curved sandpaper.

You could buy new, but many would just buy used. There are some members here that you could support, or check CL / OU / fleabay

Which metroplex, or part of FL would be closest to you? (only Florida listed in your user profile)

 

In one of the images posted in post #4, I noticed the two nuts (circled in the attached image) are loose. Did you loosen them off? Also the bracket secured by those two nuts looks to be upside down. @TMR-JWAP, correct me if I am wrong on the orientation of that bracket.


If you didn't loosen those nuts, they need to be tightened up. This is an important ground point.

 

Be sure to retorque those nuts to 48 inch pounds (aka 4 foot pounds). You could also gently clean them with a tooth brush.

Make sure the ECU plug is as clean as the socket.

The staining on the rail, was that from the recent cleaning?

 

Yes. Try the brush and the deoxit.

Again with the deoxit, not sure if anything would clean better. The socket/plug should be fine after this cleanup, or until it corrodes again.

Usually that staining is from leaking modules. Wouldn't worry, just something to be aware of.

Do you park in the sun with the windows up?

 

Try mating the socket and plug together when using the deoxit, maybe that will help clean it up some.

That battery is basically new with only 30k and 3 years on it. In the future you might top charge it by using a HV power supply.

Crack the windows when not raining, and consider tint (ceramic is best) and or window reflectors. I've seen some DIY reflectors made from insulated (metallic clad bubble wrap) food delivery bags / boxes, people post them on CL hoping someone can repurpose them. Always use the AC when above 80F, and you might want to overdrive the HV battery fan to keep the battery on the cooler side.

When cleaning the HV fan, pay attention to the nearby white connector/socket, which is a known point for corrosion as well.

 

Do another OBD2 scan, is the only code (DTC) being reported P3030?

Before buying a used ECU, here is the workup for DTC P3030 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/20zmw/cip3030b.pdf

You might test the No.2 wire frame first, likely one of the voltage sense wires is broken at a busbar. A replacement is around 60 usd.

 

On page 05-933 starting with step 6. Requires removal, and testing with a multimeter. That wiring harness is delicate, even if it doesn't test bad, it could break during reassembly. Hard to believe it corroded to failure in 3 years. If bad, spend the 60 for the replacement.

Curious if one of the voltage sense wires corroded/broke off near that staining?