2012 repair help

I am helping a friend with his repair.
He recently bought a car with 180k
Jtdkn3duxc1487151

His coolant diverter y coupling got a hole and he overheated, he summerized a blown head gasket. He used blue devil to patch the leak (put blue devil in overflow resivour and removed the thermastat from the engine (just found out this part today)) the engine has been turned over a few times by jumping it but dies immediatly before idle. So it hasnt been ran. He replaced the plugs and air filter.

This this when i joined in. He jumped it for me and i saw what it was doing. I read that it could be fuel pump relay or mas air flow sensor or coil pack. We unplugged the mass airflow and tried a jump while maf was disconnected.
It turns over then dies when jumped.

His battery was old and dead also, maybe from trying to start it too many times (battery age is unknown) He replaced the battery connected the maf and read the codes. P0113 p0102. Was this because earlier we unpluged the sensor and tried to start it?

Later he removed the air filter box to visually inspect the outside of the intake manifold. His roomate sugested this because he suspected a vaccum leak. (No obvious visual damage)
New codes, p0121 p0123 p2135.
Replaced the y coupler. Remounted the air filter and assembly. And with the new battery, attempted to start, nothing.
Battery showed low voltage on center display. Jumped it from under the hood. The engine tried to turn over then dies like before.

Im trying to help over the phone with fb messenger.

I know the HG is a problem because the aluminum block. But i dont know if its really blown or if things are really screwed from the over heat. I only know this was his assesment because it died after overheating. Now the blue devil is setting in the reservoir.

Do we need to rest the codes now that things are reconnected in the engine for it to work right?

Why would his display show the battery low if it was just swapped?

Now we have a code reader i feel like we might be able to track down repairs but the battery showing low is concerning.

I was trying to figure out the trouble shooting step before we had the reader but now we do, so id like to proceed in an order that makes sense. I dont know much about cars but have done a fair bit to my 94 ranger. (Iac valve, erg, plugs, altenator, starter etc.) But i have come to his vehilce in a far worse state than my experience is fimiliar.

Any help would be appreciated

 

I am new to prius and understand there is a bit of difference. But i dont know / understand the differences.

The history is unknown to me but...

The car was running till it sprung a leak, it died when it overheated.

I will look into charging the HV to see if it can be done before replacement it needed. Any help on charging or testing it for need of replacement would be helpful.

It is very helpful to know it starts off that battery. Out of quriosity, what functions does the smaller battery preform?

 

I was told it happened to the current owner. I saw the hole in the hose fitting. Overheating...was explained by owner.

As far as codes go... i will read about the codes listed.

P0102
P0113
P0121
P0123
P2135

But since we unpluged the maf and tried starting it i wonder if the first two were false. Would the code still show after its reassembled if the maf is good. Meaning is it stored or does the comupter only give you current problems and clears itself of things we repair as we resolve them?

 

The Hv will try to crank for a short time. At other times it wont. When the old 12v was on we chargered it and got a better crank, thats why i misunderstood what its job was. But that confuses me some too, because of its effect to get another crank from the HV. Unless the hv get a little juice from resting. I will search out grid charging next.

Any idea what the compression should be for each cylinder?

 

P0102
P0113
P0121
P0123
P2135

The list goes on.

P0000 x4times
P0351

 

Can i hook the hv up like this...

And use this to charge it?

And use this to charge it?

Tenergy T180