Help for hv battery
 

Hello
I would like a help for a 05 ford escape hybrid. The bcm got P0AA6-60 code. I can drive the car if I clear the code but whenever I turn off the car I need to clear again the code to start it.
I swapped the hv battery and put the original one that sat for 7 years now and charged it with the external charger for 8hours. It got 334v but not able to start the car with P0A1F code, and module voltage deviation fault. Mod-dev value 2.19.

Re: Help for hv battery
 

DEL_MOD_V of a heathy battery is under 0.3-ish and preferably under 0.19 - lower is better.

2.19 indicates at least TWO cell failures within one module and likely many single cell failures.

P0AA6 is a high voltage isolation fault.

What are your BCM reported leakage resistance values, R_LEAKN and R_LEAKP? A recent healthy battery I evaluated was 373,998Ω. Yours should be a similarly high number. If not, there is an isolation fault in the battery, i.e., there is high voltage to ground where there shouldn't be. This is most commonly cause by electrolyte cell leaks. It can also occur in other components where the HV system isolation from ground is compromised.

Re: Help for hv battery
 

Thank you for your help. I don't have the leakage resistance values. Since I didn't find sources for p0aa6 code I decided to swap the battery. I don't have the expertise to diassemble the battery and check the cells.
I don't know if the other battery is hot causing the high del mod values, the fans are activated directly when I put the key on acc position.

Re: Help for hv battery
 

"Hot" won't cause a substantially high DEL_MOD_V. 8 hours of charging should bring a healthy battery's DEL_MOD_V value to something relatively small.

Did the replacement battery resolve the P0AA6?

Re: Help for hv battery
 

After the first 8hours the car was starting and stop after 2 secondes because of low state of charge, I decided to do another 8 hours, my brother forgot to unplug the charger so the battery was plugged for another 18 hours without fans on it.
Yes the replacement fixed the p0aa6.

Re: Help for hv battery
 

I forgot to mention that I removed the jump starter box , I don't know if that affect the starting conditions and battery charging through the ICE

Re: Help for hv battery
 

Uncooled charging has a good chance of destroying the battery.

Re: Help for hv battery
 

I will put a fan on it overnight and see if it helps

Re: Help for hv battery
 

It won't. Regardless of whether it was before or after the charging, DEL_MOD_V > 2 is a battery that will not work in a vehicle.

Re: Help for hv battery
 

Oh wow. It's dead then. I don't know where to get a new battery soon and don't know how to fix the p0aa6.
Thank you for your help