Prius (Gen 2) :: Codes Appeared / Cruise Control Is Engaged

The 12v battery is 3 1/2 years old.

I rebuilt the HV battery in May 2015. I replaced 3 modules and took the pack through 3 charge/discharge cycles using Hybrid Automotive grid charger and simple discharger. I also cleaned the cooling fan.

All was fine for a month or so. Then I got the trouble lights but the obdlink I had wouldn't show the codes. I noticed a decrease in mileage and a slight hesitation upon acceleration from a stop.

I finally got the mini vci and a win xp laptop to find the codes:

P3000

P0A82

C1310

After maybe a week or so, the ICE wouldn't start and, being busy, I parked it for a while. About a month later, I pulled codes:

P0AA6 with detail codes 526 and 613

P3000 with detail code 123

P0A82 with no detail codes but it indicates "hybrid battery pack cooling fan 1 performance/stuck off.

I connected the grid charger and the HV fan engaged, as it should. I cleared codes and took a drive, while monitoring with Techstream. I watched the fan modes climb to 6, during driving and idling, over about a half hour period. Not sure if this means anything, but I've read that people can hear the fan from the driver's seat when it's running at 3 or 4- I forget which. Well, at 3, or maybe 4, I couldn't hear it. Even standing at the rear door, with my ear against the vent. Though, there was ICE and parking lot noise to contend with. Once it got to 6, I could hear it easily.

Battery health, at that time: With fan at 6, temp of batt tb1 through tb3 was 51.6 c, 56.5 c, 50.4 c.

Battery blocks voltage ranged from 16.05 to 16.15. Internal resistance ranged from .024 to .026 ohms.

Out of necessity, I've been driving this car again, for months now. The lights came back and the codes were still P3000 with detail code 123, P0A82 with the addition of C1310. I don't see a detail code in the same place but there is a field that says "detailed freeze DTC 156". I assume this may be a detail or sub code. Nothing has been preventing me from starting the car. But months ago there had been 2 occasions when, after having driven several miles and parked for a short time, then taking the freeway home, the car would idle high going up an overpass. On these occasions, the MFD shows a low SOC with only one purple bar. The first time this happened, it took around 10 miles before the SOC would creep up. The second time, I had it on cruise control and, while ascending a grade, the car jerked violently and acted as if I were flooring and letting off the gas in quick succession, about 4 times. I disengaged cruise control and took hills more slowly. The high idle up the hills backed off as the battery SOC increased. This time the SOC started in increase within a few minutes, as I would expect normally. I imagine that the electric motor was turning off and on, when the car was jerking, due to a low SOC.

These symptoms cleared up in a few days, apart from the hesitation on accelerating from a stop, and I've been driving it ever since. A few weeks ago, I noticed the car had major difficulty accelerating. I'll floor it and it barely moves, taking several seconds longer than it should to get up to speed. The SOC is stuck at 1 purple bar. I got the car home and turned it off. When I turned it back on, the SOC increased very quickly, only once. I now can't replicate that. The SOC simply will not go above one bar.

Another odd thing. When I'm creeping down the road, at say, 25mph, and I let off the throttle, the car just keeps moving as if cruise control is engaged.