Continuation from http://www.mynissanleaf.com/viewtopic.php?p=492766#p492766 and http://www.mynissanleaf.com/viewtopic.php?p=493278#p493278 ...
First off, I haven't followed this thread closely due to lack of interest and time. I've been really busy w/work and we have little visibility into the process, Nissan's systems, etc. 99+% of the people who get the TCU upgrade expect it to work and not require repeat visits to the dealer, calling Nissan support, etc., me included.
Since people have just been experimenting, I tried the first logical thing after getting nowhere w/Nissan support: pulling the 12 volt.
VitaminJ said:
Reading through your post history you said that Nissan support told you it may start working between 4/28 and 5/2...and now it is working (partially). The negative battery pull originated as a way to turn a partially working TCU into a fully working TCU and the culprit is low voltage on the 12v battery, typically overnight as the car sits undriven and the temperature lowers. You may indeed wait for Nissan to call you back instead.
I'm going to again suspect your 12v battery as you use a trickle charger on it, leading me to believe it's gone down on you before.
Lastly, you are talking about what you think is pointless, but what is actually pointless is removing the negative battery terminal from a fully functioning car. I'm not sure why you got that in your head as something you want to do or what it would tell you but from where I am sitting your are going about this whole process backwards. You reported a change in the behavior of your car's TCU, based on that change I offered advice, you denied my advice based on your experience from weeks ago before said change took place.
To me, it's pointless to screw around w/the 12 volt when they know they're not done on their side. Backwards? I went thru the process the best I could.
More chronology, now that I've found some time but a call or two might be missing:
Mon, 5/1 - received voice mail that they're still working on it and will get back to my by Wednesday
Wed, 5/3 - voicemail w/update on my escalated case from Sirius XM (they used these words), was sent to escalation on 4/27. They received email that it's been escalated to a lead specialist. No update. Will call me back in 2 days: Friday.
Fri, 5/5 - no phone call
At some point between 5/1 and 5/8, more stuff was working but the NissanConnect iOS app had funky behavior like being able to update but then telling me an error had occurred and that I'd need to sign out and back in. That didn't help as the error would happen again.
Mon, 5/8 - I received a call and spoke for 2 minutes as I was driving and going to be late to a work meeting if I stopped to talk in any detail. I think by that point, everything was fully working before she even called, possibly Thursday or Friday.
All had been well for awhile and even the yellow ! car icon stopped happening after charging. Everything was all working perfectly thru 5/15/17 until 5/16/17.
Today (5/16), I noticed no charging completion notification email. Status updates from the iOS app wouldn't work (would show 0 miles). Status updates via their web site (login via https://owners.nissanusa.com/nowners/) wouldn't work either. Remote command via iOS app to start charging would fail. Received auto-generated email "Nissan LEAF update: Start Charge Request Failed..."
And, no surprise, I got a yellow ! car after I returned to my car after charging today.
Sigh... It's annoying I've wasted a bunch of time on this. I wouldn't be surprised if I have to call Nissan EV support again. The original 2G/2.5G TCU never had these probs on this Leaf nor the previous '13 I leased for 2 years.
I previously hadn't cleared any DTCs since it can hinder diagnosis. I figured, well, I'm going to do it anyway and see if they return.
P3131 000B EV/HEV System Shutoff Timeout EVC-220
U1A00 0008 TCU ACC No Conn AV-194
U1A04 0008 TCU VIN Unfinished AV-198
U1A05 0008 TCU USB Comm AV-199
Let's see if these return. I have a screenshot from 4/28 w/the above DTCs present, just like they were tonight (5/16).
As for 12 volt, I keep it topped up for a potentially longer life usually once a week or so, since it's well-known the charging algorithm is crap. Lead acid batteries like to be full. The algorithm doesn't do that at all. I also move around my car often 1-2 times a day besides a short drive + normal driving, which means it's drained more for startup and there's very little DC to DC converter on-time during the moves. And yes, once I had a scary no start situation w/my uncalibrated OBD2 dongle showing a low voltage. (I'm pretty sure this was BEFORE I paid for the 3G TCU uprgade.)
The 12 volt that came w/my used Leaf went bad and was replaced for free in Oct 2015 (http://www.mynissanleaf.com/viewtopic.php?p=440192#p440192 then http://www.mynissanleaf.com/viewtopic.php?p=440419#p440419). The replacement looks rather different than the original.
edit: added clarification as to when I had my one time no start episode on my replacement (current) 12 volt