I was thinking that the '1600' is just a general code that says there's an IMA problem, without any specificity. But here's the General Description from the troubleshooting manual, can't say I understand it:

"General Description
This DTC is used to determine if a malfunction is on the engine side or the IMA side when checking with the HDS. When device on the IMA side malfunctions, the motor control module (MCM) signals the engine control module (ECM) to turn the MIL. If the ECM receives a signal from the MCM to turn on the MIL, the MIL is turned on and a DTC is stored."

Your description of your symptoms (except the lack of a 1447 or 1449 code) sounds like boiler plate 'pack unbalanced, getting old, deteriorating' stuff. I don't really have any tried and true, one-size-fits-all strategy. I'm sure someone else does though... You might want to just start with a grid charge session and reset the computer by pulling the under dash number 18 fuse... If it were me I'd probably check voltages at the voltage taps (10 taps, one tap per 2 stick pair) and see if any taps stand out, most likely low voltage, and then decide what to do. For example, if one tap's voltage were 0.2V or more lower than the others (S. Keith's value), I'd probably open the pack and find replacements for those sticks before I did anything else.

But in any event, grid charge, reset. Try it out. Maybe start thinking about deep discharging followed by another grid charge session...

 

IMA System Malfunction P1600

+1^

p1600 code sheet from repair manual is in the link below, [same as p1601]
https://drive.google.com/file/d/0B6EDknyr-8unVGR2Rm9td1lDYUU/view

For ref: IMA SYSTEM.pdf from repair manual [see: Precautions pages]
https://docs.google.com/file/d/0B6EDknyr-8unMFJhRzF2emdEeU0/edit

Here's the P1600 codes in IC via google; also, the P1601 posts in IC

More info on codes and safety info from the manual etc [i.e. ground locations] can be found here: codes spreadsheet link as a googledoc.

 

Check your fuses... sounds like the MCM isn't powered, or there's a cut in the IMA wire harness between the MCM and the ECU, namely of MOTFSA or MOTFSB.

 

Update-that's-not-really-an-update: I do have ONE bar on the SOC (thought there was none). Also, I'm almost done with my charge/discharge/charge cycle, so tomorrow may give me some answers.

Still, in case that doesn't solve the problem, can you help clarify some things? Sorry in advance for the all the clarifying questions, but I'm not well-versed in all this stuff.
Which fuses would I need to check?
Where would I find these fuses?
And lastly, what would I be checking them for?

Thank you!

 

If the soc gauge really is blank, and you have no ima codes, only ecm ones, then mudder is prob on right track with lack of 12v power to MCM/IMA.

Check all ima 12v side fuses first and report back..

 

Engine Bay Fuse 16 powers a TON of things, including the MCM, but also the Gauge Assembly, cabin lights, tail lights, radio, etc. Glad you figured it out, but were none of those other subsystems working, too? In other words, can you clarify whether Engine Bay Fuse 16 was burned out? Or was it some other fuse? Engine Bay Fuse 16 would certainly cause MCM problems, but you would have had many other problems, too (e.g. none of your interior lights or tail lights would work).

 

^I think he was saying that he simply pulled the #16 fuse to reset it, not 'replace' it because it was bad...

 

You are correct. I was trying to think of a way to say it but nothing seemed to make sense. I did not buy a new one. Simply pulled it out and put it back in. Should have just said that.

Thanks for the help, everyone. For now, it seems I've solved the problem, which appears to just have been a slowly dying battery pack in need of some loving.