L2 not charging, L1 ok

[gbarry42]

By the way, does anyone know is there is a thread on here for tire problems or tire wear?

Yes.

(pregnant pause)

Oh. Here: http://www.mynissanleaf.com/viewtopic.php?f=4&t=7531

[pjoseph]

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.

[gbarry42]

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
--------
$253.13 . . . Oh, well, I guess my get-rich-quick scheme won't work after all

(Prices and calculations for entertainment purposes only. No need to point out errors. Licensed drivers only. Void where prohibited.)

[JCBNJB]

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).

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

[jimcmorr]

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.

[JCBNJB]

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?

[Ingineer]

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

[pjoseph]

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.

[garygid]

1. Glad you got your LEAF fixed.

2. Ingineer, thanks for the correction on diode shorting.
I did not know. I modified my previous post.

[Ingineer]

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