P0A80 and U0100 errors on Project Lithium Pack

Look at the freeze frame data for the P0A80 code. What is the voltage difference between the highest and lowest battery blocks?

I am guessing that one of the lithium blades is bad.

 

Open the HV battery computer and take a look at the bus bars that go from the receptacle to the green board You see one or two of them or caked with white crusty crap . Clean that all up with electrical contact cleaner the good stuff and then look throughout for other traces of corrosion bus bars nuts etc The white and green bluish patina forming on corners of battery modules and things like that.

 

I would think you'd be looking for similar things that you'd be looking for with the regular pack and after reading something about some of these lithium packs I'd have to have a look and then computer looking at the different modules to see if anything's getting hot running completely differently than other ones etc maybe talk to the guy who built the thing.

 

Others have already talked about the P0A80. As for the U0100 code, that's a communication problem between two ECUs in the car.

One of the ECUs is the engine control module (ECM), because that's what the U0100 code means.

The other ECU is whichever one is reporting the U0100 code.

Here is where some scan tools are a lot more helpful than others. There are some scan tools that just plug into the diagnostic bus and shout "hey, who's got trouble codes?" and give you a big list of all the codes that come back.

There are other scan tools that will break out that list by which ECU(s) reported which code(s), and you can see how that's especially important with any communication code, because that's how you know which two ECUs can't communicate with each other. One will be the one the code itself refers to, and the other is the one reporting the code.

According to an old 2006 edition gen 2 repair manual floating around, the only two ECUs that can say "U0100" are the HV control ECU and the battery ECU, so it has to be one of those that's saying it can't communicate with the ECM. (For a 2009, though, it could still be worth looking in a current 2009 repair manual, as they could have added more ECUs that try to chat with the ECM. Or just use a good scan tool to be sure which ECU is saying U0100.)

The "CAN COMMUNICATION SYSTEM" section in the repair manual can be helpful in troubleshooting the communication issue.

 

Do you still have the old hybrid vehicle battery that you took out of the car?

 

Post #2 suggested looking in the P0A80 freeze frame to see what the voltage readings were at the time the code was set. The BMS makes its health judgments dynamically, under load on the battery; you can't really second-guess it by poking around with a meter making static measurements.