2003 Prius Won't Start after HV Battery Replacement

Oh yes, but I would still change the front bus bar so you will not have future issues and clean that rear bus bar

I used a wire wheel on the copper tabs and soaked the nuts in electronics parts spray in a cup. Tabs just pop out

Point is to get rid of all green patina

You can get it on eBay or dealer

 

Just be very careful of those sensors, they are ridiculously thin and brittle

Try to get some contact cleaner down the wires if you are going to try to clean the front bus bars

Please remove bus bars to clean and take this opportunity to static test those supposed dead cells, I bet they are fine

 

For the heck of it, hand measure the voltages on every module of the first 5 blocks.
Just want to be sure there is not a short in one of the first few modules

Then buss bar and connections for #3 should be inspected and cleaned.

You see how in your techstream reading it reads the first few Blocks
Block 1 = 15.30v (module 1, module 2)
Block 2= 15.37v (module 3, module 4)

But then the next block is only like half the voltage of a normal block
Block 3 = 8.37v (should be module 5 and module 6)

And then the readings drop off to nothing, basically. (under a volt)

So it's like the power can't get through after Block 3 (module 5).

edit: And if it were me, I would replace the wire looms for both sides. The money spent would be worth the peace of mind of knowing all the wires and connections were free from corrosion.

 

Remember use BRASS wire wheel Steel will eat the copper tabs. Use Eye protection and gloves.

 

I fear you may have damaged a module or two due to initial over torquing the terminals. Man, that sucks.

 

P1455 is the least of your worries.

Let's start with the hybrid battery.....
Easy to see block 13 is a problem child.
14.37v when others are above 15v :-(

Next the p3009
Click the "snowflake" next to the p3009 code and show us screenshots from that code.
Code be you have a transaxle high voltage leak, not a hybrid battery leak.
As others have written before me....ground fault could be at any system in contact with high voltage: traction battery, traction battery ECU, battery cable to inverter, inverter, transaxle, etc

 

It probably not the buss bars, it is the wiring/ring terminals.
I bet you could aggressively probe them and figure out the bad one(s).
It's likely corrosion crept down the wiring itself.

Replace the looms. You will get new wires and new buss bars.

 

Probe with a firm, nonconductive stick for example. Move them around enough to confirm that there are not breaks in the wires.
Yes. The loom is the entire assembly of the orange colored wires.

 

Key word NONCONDUCTIVE

 

Drive with the AC on, it will help pump cooled air into the HV battery.

Open window will just add outside hot air to the intake vents. Oh yeah, make sure vents are not blocked in any way.

 

Leaving that plug undone is what caused all the low/zero readings.

 

This is absolutely horrendous. Your battery is so far out of balance, you will be fighting codes all the time. Best case, that's approximately a 15-20% imbalance. Considering that you only have 40% SoC range, you've lost 50% of your usable capacity due to imbalance.

Individual module voltages should be less than 0.05V difference