2004 Gen2 Prius faulty hv battery ecu

Hi all,

Background..... I live in the UK where it can tend to be alittle wet especially in south wales where we get alot more rain and damp conditions than most other areas of the UK.

I purchased a full electric vehicle last may, which meant the prius wasnt getting used, so its been pretty much been stood on the driveway in the cold and wet conditions.
I have started the car every few weeks to make sure the hv battery wasnt getting low on charge.

Anyhow, this week i went to start it and got the red triangle. Plugged in the obd read the codes, code P3030.
Interrogated the hv battery module voltages and blocks 1 and 2 were reading 0v and 25v, all the rest were 15.1v. Not good.
Done abit of reading on here and seen that sometimes the battery ecu inside the hv battery case goes faulty.
I removed the HV battery, removed top covers to expose the individual cells, all cells were reading the same and in good balance, so this points to a faulty hv battery ecu.

Unplugged the cell tap connecting block from the battery ecu and examined it, found a few pins with corrosion on them to a point where the corrosion had spread to neighbouring pins.
OK, removed the ecu, unscrewed the cover of the ecu to examine inside, found a few tracks in the ecu in not a good condition, suspect ecu is kaput.

Now for the specific advice please. I`ve been searching auction sites for a spare gen2 hv battery ecu, checking the part numbers etc....
there are a few around relatively cheaply that look in good shape, but the part numbers are not exactly the same as the one I have.
The part number on my ecu is 89890-47070 other number is 469000-0103

others for sale are 89890-47080 and 469000-0141
also 89890-47091 and 469000-0200

I`m hoping any of these is suitable as a replacement, can anyone please advise if they are all ok to use.

Also, when i do replace the ecu, does it need to be programmed into the main ecu of the vehicle, or are they plug and play.

Thanks for the advice on the above.

Anthony.

 

awesome info, thank you very much.

 

Hi Brad,

I did check the continuity of each sense wire from the plug to the battery when i had it all apart. The ecu sense plug entry had scorch marks on and around 3 pins, and the scorching continued onto the pcb and very fine tracks on examination.
Ive placed an order for one now, i`ll report back next week when i receive it and had a chance to fit it.

Thanks.

 

hi brad,

thanks for the link, read it just now, very interesting and have given me a few more things to do.

Is it possible to remove the pins from the plug to examine them individually and clean them individually, if yes, how the hec do they come out of the plug?
I have here 100% isopropranyl, is this ok to clean the battery terminal and sense wire crimp receptacle.

Im thinking of removing each sense wire individually and cleaning them, and the battery terminal to remove all residue and build up, then test each sense wire for continuity before they get refitted.

At least this way everything / all contacts will be thoroughly cleaned. At the end of the day, they have been there undistrubed for 13 years already, a good clean and electrical check is a god idea.

You think this a good way to proceed?

Thanks

 

Hi ed,

I received the e placement used ecu on Monday. Yesterday, I removed each battery sense wire from the battery and tested each wire individually fro continuity and security of the wire onto the crimp end. All wires were OK.
I used a hard toothbrush and cleaned the residue powder / corrosion off the battery terminals, the copper buss bars were all OK, the corrosion was essentially only round the securing nut area.
Anyhow, cleaned off all the crap off the buss bars and nuts and re secured the sense wires. I did use a very fine coating of vaseline with a brush over the nuts to try to avoid the build up of corrosion on them in the future.
I did use iso propranolol to clean the multi plug end along with a very fine small pipe cleaner to try to clean the inside of the terminal pin crimp ends.
Re installed the battery back into the car, along with the replacement ecu, powered up, tested, all now fine.

Used techstream in live data to check the battery for charge and balance, all now ok.

Car is now operational again.
I'm hoping not to do this job again anytime soon.

There was no need to clean off the old pcb of the ecu as it was clearly burnt in one area so left it alone. I did check the pcb condition in the replacement ecu and it seemed ok, nice and clean with no visible track burns or corrosion on the pins on either side of the pcb.

Anthony.

 

Well, after 4 years, the fault code P3030 is back again.
The car had been standing for some time not being used.
I have removed the battery ECU and there is discoloration on the tracks on the pcb from the connector to the chips.
Techstream shows good battery IR and good balanced cell voltages, but its throwing the P3030.

I`m going to get a replacement of ebay and stick it in and try it.

Think then it maybe time to sell the car onto a new owner.
Its only done 88000 miles on a 2004 year.
Im sure i`ll have not much trouble selling it when running fine with that mileage on it.

I`ll report back when the new battery ECU arrives and its fitted.

Glyndwr.

 

Update.
I have fixed the battery voltage sensing ECU.
It was a broken tracks issue on the pcb taking the battery voltage sensing signal from the plug to the chips on the pcb.
In total, 3 tracks were open circuit, so I replaced the tracks with wire soldered to the relevant places on the pcs bypassing the damaged tracks.
Successful and tested in the car, no error codes showing.
The bad tracks were from R879 and R880 going to the IC pins 5 and 8,
the other was pin 5 on lower pinset on the connector to R871.
See pics before and after, to see if you could also repair your damaged tracks on the pcb in the future.
I was overjoyed with myself that i managed to repair it to be honest.

Glyndwr