L2 not charging, L1 ok

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L2 charging failed again after working for just one day. Back to square one. Plan on taking it to the dealer tomorrow.
 
Here's the very helpful update i got from Nick, the service technician at the dealer.

I brought your LEAF in the shop this morning to perform some tests on the charging system diode, and to pull trouble system codes. Unfortunately there were no codes stored but the diode check was enough for nissan engineers to deem as a failed part.
We are ordering an on board system charger..


This thread will hopefully be of help for the next LEAFer who might run into this particular issue. Only 2 have been reported so far (including mine).
 
garygid said:
I would be a shame if the diode blowing (or shorting?) requires a whole new, non-noisy Charger to be installed into your LEAF.
Unless it happens in 2013 and they end up giving you a new 6.6 kW charger! :lol:
 
DarkStar said:
pjoseph said:
Took the car in to the dealer's service department. We managed to duplicate the problem just exactly as Davewill had mentioned above. Charging works on L1 & AV, but fails on Chargepoint & Schneider.
Ding! I know what the problem is!

The diode in your charger unit is fried. The L1 & AV units don't test for the +/- 12 volt signal, while the ChargePoint, Schneider, and Blink do.

A guy here in Portland had to get his whole charger unit replaced in his Leaf because of a problem with very similar symptoms.
Gee - if SOME GROUP of Leaf'rs had problems with their on board charger(s) which continued causing RFI throughout their house . . . . and Nissan ignored it - and continued to ignore it . . . month after month . . . it'd be a crying shame if those SAME Leaf'rs managed to fry that same diode in THEIR on board sharger, wouldn't it? Accidentally of course. They'd ALL get new on board chargers (more quickly), in stead of just having to wait for ALL ETERNITY for Nissan go get around to simply adding a new filter for their noisy on board charger. Gee ... they wouldn't even have to wait until heck freezes over before Nissan got of their numb back sides to take care of the old issue. Gee - I wonder which is more costly ... a measly torrid, or an entire charger. Hmmm. :evil:
 
Mostly, when diodes blow, it is an open-circuit, not a short-circuit (***).

(***) Correction from Ingineer:
He says that Diodes usually fail by shorting (closed circuit) rather than open-circuit as I suggested might be the case. I did not know that. Perhaps signal, power, and Zener diodes are different? Recently, some of my Zener Diodes have failed (overheated), going open-circuit with no increase in current.

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An open-circuit at the diode might just make the car not charge at all, since the EVSE might not detect the car being plugged in at all.

Hard to say for sure what would happen with any particular car-EVSE pair. But, likely no charging.

-------
A closed-circuit failure would give the "charge OK by some EVSEs, but not charge by other ECSEs" symptom.

The EVSEs that do not check for the diode (AV, Nissan L1, etc.) would work, but those EVSEs that DO check for the diode (as they should) will (normally) refuse to charge.
 
Yeah, you need your charger replaced. The diode went out in mine, I had the same problem and they had to replace the charger in my car. I'm in TN and I was second to have this problem. Walsh in WA was the first and he help to solve this problem and made it easier for me.
 
garygid said:
Mostly, when diodes blow, it is an open-circuit, not a short-circuit.

An open-circuit at the diode might just make the car not charge at all, since the EVSE might not detect the car being plugged in at all.

Hard to say for sure what would happen with any particular car-EVSE pair. But, likely no charging.

Gary, This is a clear explanation of what i am seeing. Although there is the rare occasion (such as the one when both the car & the EVSE sat idle for nine days) that L2 charging worked for a day or so.

Have been on L1 charging for almost a month now. It is tough to drive 75 miles a day with this, so i've had to plan my trips carefully and drive ECOnomically. Otherwise the car drives fine, and that has been the saving grace.
 
garygid said:
A simple resistance check between the CP (Control Pilot) input pin and the Ground pin on the LEAF's J1772 socket, with the LEAF Off ... should check for the diode: The resistance should be about 3k ohms in one direction (polarity) and very high resistance (probably over 100k ohms) in the other polarity.
Hey, here's a opportunity to build a little tester...maybe we can sell them to people who don't want to bother with an ohmmeter. I know, we'll build it right into the connector. Let's see...

$0.38...2x LED
$0.57...3x Resistor
$1.29...9V Battery
$0.89...Chip (555 or a PIC)
$250.00...Connector :eek:
--------
$253.13 . . . Oh, well, I guess my get-rich-quick scheme won't work after all :lol:

(Prices and calculations for entertainment purposes only. No need to point out errors. Licensed drivers only. Void where prohibited.)
 
Well, I am sorry to say I might be the next case of diode disease. Woke up this morning, no charge, no lights, no motor cars, not a single luxury... (sorry the song popped in my head as I was writing). :cool:

No blue lights on the car. Blink seems to be operational. Turned off the charge timer on the car (one solid blue light on the left that I never noticed before but I assume means ready) tried again, nothing. Came to the Forum, as always, you folks have all the answers, plugged in to a 110, now charging.

Guess I will call the dealer later today and get it fixed. Will let you know what I find out. If I'm missing anything else I should try, let me know.

Thanks for all of your continued wisdom!

Judy
 
pjoseph said:
garygid said:
Mostly, when diodes blow, it is an open-circuit, not a short-circuit.

An open-circuit at the diode might just make the car not charge at all, since the EVSE might not detect the car being plugged in at all.

Hard to say for sure what would happen with any particular car-EVSE pair. But, likely no charging.

Gary, This is a clear explanation of what i am seeing. Although there is the rare occasion (such as the one when both the car & the EVSE sat idle for nine days) that L2 charging worked for a day or so.

Have been on L1 charging for almost a month now. It is tough to drive 75 miles a day with this, so i've had to plan my trips carefully and drive ECOnomically. Otherwise the car drives fine, and that has been the saving grace.


I had an intermitent problem in my VW Passat which caused a check engine light and a fault code pointing to the Cam Chain Tensioner. Wait... I know.. that's an ICE... let me finish.. This ultimately was traced to a cold solder joint in a relay hidden somewhere. The relay was replaced and presto the problem has not come back. In my case I think the solder joint became heated by current flow through it. I'm not suggesting the LEAF problem is as simple as replacing a relay but just pointing out that a cold solder joint could account for the one day 'remission' of symptoms.
:D
 
Had to leave the car at the dealer. In spite of providing the tech with the Forum Wisdom he suggested we may need to see if it's the EVSE or the car. :( As expected, it charged properly at the dealership using their AV EVSE. He said he will call Nissan TN tomorrow and see what they say. Hoping I don't need to waste time re: the Blink EVSE question and instead can just get them to check the diode.

To the OP and others who had this happen/know of it happening, was it a big deal to get the dealer to run the diode check?
 
Guys,

First off, Diodes (and most semiconductors) usually fail SHORT not OPEN as Gary suggests. Only after a diode shorts then sometimes it will fail open after experiencing high currents due to the short condition. (Bonding failure in most cases)

Secondly, From reading the posts, I'm not convinced this is the so-called "Diode" fault, Rather, it could be caused by a resistance change in the pilot circuit, or even a ground fault. In any event, even if it is a diode, this is located in the on-board charger module and it is not a separately serviceable part.

There is a good likelihood it's something out-of-tolerance in the pilot circuit, and both the Nissan (Panasonic) EVSE and the AV unit are more forgiving in their pilot discrimination than some of the other units on the market, Diode or not.

-Phil
 
JCBNJB said:
To the OP and others who had this happen/know of it happening, was it a big deal to get the dealer to run the diode check?

The Leaf technician at the dealer turned out to be a really nice guy*. He patiently listened to my explanation and then drove with me to the nearest public EVSE (ChargePoint) which was ~3 miles away. That was how we characterized the problem quickly.

He then called the Nissan tech line who wanted to remotely diagnose the car (unsure if they used Telematics or a connected port). That got them to conclude a failed diode.

Update: Got my car back today with a new on-board charger. It's looking good so far. When i connect the J1772 handle, there is no more of the clanky handshake sounds that the car used to make. It appears they modified the 2012 chargers a bit.

* His e-mail follow-ups were quick and thorough. Overall Nissan service was outstanding. While the sales experience was routine, exceptional service has made me a fan of this dealership.
 
The "Clunk click Clunk" sound when you begin charging is not the charger, but rather the battery contactors performing precharge and then closure to connect the on-board charger to the pack. This will still occur, so I suspect you are mistaken that this is no longer happening on your car.

-Phil
 
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