First Issue in 10 years and 227,000 miles...Need Advice

I don't know what those codes are, maybe someone else can help with that. I wouldn't leave that OBD2 plugged in. Some of those have lights that could drain your battery. Maybe that's whats happening.

 

some have had this issue, your battery is probably fine.

 

DTC P0A1D means that the hybrid vehicle ECU has an internal error.
DTC U0100 and U0293 are both communications errors. U0100 is posted by the hybrid vehicle ECU and this means it cannot communicate with the engine ECU. U0293 is posted by the traction battery ECU and this means it cannot communicate with the hybrid vehicle ECU.

I suggest you disconnect your OBD-II scanner and see if the warning lights return. If they do not, then there is an incompatibility between that OBD-II device and the Prius. If the lights return then you should seek professional assistance - or else try to buy a used HV ECU (located behind the glove compartment) and install it.

 

Yes, yes and yes.

And you should tackle them in that order:
Unplug the scanner when not in use (on startup and shut down)
If the 12 V is old have it tested or just replace it.
Only after those two things should you look for other mechanical or electrical causes.

 

On my gen2 when I plugged I the scan gauge2 after having installed it in another vehicle the gen2 would throw codes which I would simply ignore and clear, never gave them another thought.

 

I'll be surprised if it is not the OBDII device.

 

If you like obtaining operational parameters from the various Prius ECUs, get Mini VCI. It runs on a Windows XP or Windows 7, 32 bit OS laptop so it is not intended for daily use - but when you have it plugged in you will obtain much more info than you probably want to know about the various systems.

 

You might also try a ScangaugeII. Out-of-the-box it only tells the more mundane things, quite a few, but it's possible to add in XGauges, basically more esoteric gauges. I think HV battery state of charge, for one. I've added ACw (AC wattage, lets you know when AC is running), and BT2 (temperature of hybrid battery's middle temp sensor, typically the hottest). Never had a compatibility problem.

 

I had a Scangauge, and sold it on ebay when I discovered the mini-VCI and techstream ($35?)

 

What you describe sounds typical for the failure of electronic components. Reset and resume, but the interval between failures get generally shorter each time. Other times, you may get one failure episode, then later it fails completely.

 

The scan gauge is small, mobile, and can be always on when you are driving. The mini-VCI is not so much any of those things, but gives much more functionality in a non-mobile car.

 

mini-VCI and techstream is mainly for diagnostics, hooked up to a laptop? When stationary? My needs are more for on the road, getting feedback as I drive.

 

Well, the car doesn't have to be stationary, but given a laptop being involved, you probably would not want it to be hooked up at all times to the OBD-II socket.

 

Well, avoid the cheap ELM clones.

 

I drive around all of the time hooked up to my netbook. It blows away the data you will get On the scan gauge.

 

Yeah I don't doubt it.