Onboard charger capacitors failed

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sujeeva

New member
Joined
Dec 24, 2018
Messages
3
Location
Colombo
ZEO 2012. Car on and go to driving mode. But cannot charge using AC charger or DC charger.
DTCs P3173, B2631 Sunload sensor, B2840 On board charger
Cleared errors. plugged AC charger. The car recognized the charger and started to charge. But fail after 5 seconds from the time when the AC charger plugged in.
Scan the car to get B2840 962E and P317 00C0. I did that several times, but it got the same result.
Some times, P3173 cannot clear. Several times, sometimes it gets cleared.

Tried DC Fast Charger. It went all charging sequences. But the charger did not got current request messages to inject current. So, the fast DC charger stopped working.
After that, the car showed errors B2840 962E , P317 00C0 and B29C1 9428. Tried several times, but failed.

Then disconnect the onboard charger of the vehicle and opened covers. Noticed that there are two burnt capacitors. No other burning signs.
Repairing of the onboard charger has not been guided b manufacturer, but decided to replace the burnt capacitors since the cost of even a used onboard charger is costly.
1. Has any done this before?
2. What could have caused this?
3. Will the replacement of Capacitors be successful?
 
I would start with the capacitors.
I'm assuming they are polarized electrolytics.
Got any numbers for the voltage and microfarads?
 
Oilpan4 said:
I would start with the capacitors.
I'm assuming they are polarized electrolytics.
Got any numbers for the voltage and microfarads?

Thanks!
They are non Polarize capacitors. One is 1.0uF 275V LE105 and other is 3.3uF 275V LE335
My order will arrive on Friday, any further opinion?
 
I am also interested in your solution! I opened up my charger and found one very badly burnt.. capacitor? it is so burnt that I can't even tell what it is. I am interested to see if you have pictures? I am trying to find out the part number of the component so that I can order one to replace it.

Charger Model is
296A0 3NA5A

Component that is burnt is the large block component next to the filter inductor on the bottom board.
 
Just FYI, there are lots of types of capacitors and I wouldn't be surprised if this is one that is not readily available 'off the shelf'. You might want to try to source a new PCBA from someone parting out a Leaf of the same year as yours. While a capacitor may seem like a simple device they are not, especially for high voltage and/or high power applications.
 
Here is a datasheet for the AC input filter safety capacitors that the OP mentioned.

Yw8RjCV.png


@Rusty, we need to see a picture to know which ones you are referring, there are several inductors in the OBC.
 
This is great info except for the lack of follow up! Have any of you with this problem tried to repair their chargers? What was the result? Negative answers are at least as useful as positive :)
 
I am also having the exact same two error codes that do not clear:

B2840 962E CHARGER On Board Charger
P3173 00C0 EV/HEV On Board Charger Sys

My 2012 Leaf with 88k miles throws a fault on the trickle charger and will not charge on it or our L2 First Gen JuiceBox. When I plug it in, it beeps once for the proximity, but no lights illuminate, and the OBC does not make any noise.

The car will still drive, but I am rationing those miles to drive a little every few days so that the car doesn’t sit static indefinitely. We live in Mississippi and the nearest Nissan dealer won’t touch it, and our nearest Leaf dealer hasn’t ever seen anything like this, and is well out of range, even if it had a full charge. The amber EV Warning light on the dash is illuminated, and if I’m being embarrassingly honest, has been for months, but I was too cheap to buy Leaf Spy Pro for my unactivated Android phone until recently.

As I rack my brain for anything that could be related: the charge cord has ran under our garage door for years, and while we have kept a block next to it to keep the door from crushing it, I wonder if it’s related. Originally, I could get the amber EV warning light to go away by plugging it into the Nissan L1 trickle charger, But it eventually would come back after L2 charging. A few months back, after I plugged it in with the L2 charger, I wiggled the cord and it stopped charging and then started again. I don’t believe it’s happened more than once, but remains possible it’s related.

Again, now neither my L2 charger nor the L1 charger that came with the car originally will get more than a proximity beep when plugged into the LEAF.

I am used to working on my ICE vehicles, and feel like the service manuals give me enough information to change out the charger if necessary. My biggest concern is that 400 V is significant, and I have to convince my wife to let me work on it. While I would like to believe that my issues are related to the “diode“ issues others have talked about, it seems like there are more layers to these codes, which might actually necessitate replacing or at least removing the whole charger.
 
The B2840 points to the OBC more than the P3173. i posted this in another thread but can't find it rn, it may be in the technical or engineering section. i have a 2012 OBC dismantled on my workbench and have many of the circuits traced out if you decide to repair yours.

1tOD19i.png


There is a Waffle Plate™ located underneath this bottom board with the HV diodes and switching transistors, but it rarely has ever had an internal failure. Typically it is the AC input filter caps and you will easily see when they spill the beans.

g2N30PI.jpg


The Waffle Plate™
CXEyQ5t.jpg
 
nlspace said:
The B2840 points to the OBC more than the P3173. i posted this in another thread but can't find it rn, it may be in the technical or engineering section. i have a 2012 OBC dismantled on my workbench and have many of the circuits traced out if you decide to repair yours.

Thank you for your response. Unfortunately, after reading through everything that I have, though I have limited experience with this, I agree... the B2840 is not a good sign.

I would like to at least attempt to fix the charger. If I can’t, I would like to replace it myself and save all that $$$ on labor.

My biggest question(s) revolve around the safety protocols on how you get the charger out of the vehicle. I know it’s the point of the document, but the dismantling guide scares the $#@& out of me. Yet, it seems to me that if you perform the discharge procedure for the capacitor and 12 V properly, with a high-quality set of high-voltage rubber gloves you should be good. I have watched the EV Enhanced YouTube video numerous times, and I feel that compared to some of the major repairs I’ve done on ICE cars, this is straightforward.... other than the undeniable threat of electrocution.

Is my fear overblown? Or, as long as there’s not physical damage to the harness/battery/etc, is it really relatively straightforward? Again, thank you for your response and help.
 
It's a straightforward task. As long as the car is not ON there is no HV external to the pack--the main contactors must be energized to put HV outside the pack. Disconnect and remove the 12V aux battery and the contactor coils will have no possible power source.

But always check with a voltmeter to be sure--if there were some strange situation such as a wrecked car in which the contactors welded shut then that could be a fault which could leave the cables hot. Not very likely at all, but until you feel comfortable it's better to measure first before you touch.

The dismantling guide is intended to scare you, but you won't be handling any hot HV wires.
Trust, but verify with your meter.
 
I decided to work on the charger myself. Getting it out took a bit, and I disconnected more than probably necessary underneath the car, just to be safe, but it is out and on the bench.

When I opened up the onboard charger, shards of black components were rattling around on the back (below the bottom circuit board).

Ejnvq9EXYAE8IQz


Upon closer inspection… This is about the most useful piece that fell out.

Ejnvq9FXgAAlAoo


nlspace said:
Typically it is the AC input filter caps and you will easily see when they spill the beans.

I’m going to guess that this is not the same thing you were referencing and instead is coming from the high-voltage side on the underside of the bottom circuit board.

For the life of me, I don’t know how to get that bottom circuit board out so that I can check on the bottom side. I’ve taken out all of the screws, but it seems to be held in by something… The brass pins maybe?

Ejny1RwXgAEgAdp


This is probably something straightforward to an electrical engineer, but I appreciate any guidance you are willing to give. If I’m fortunate enough to be able to accurately diagnose what needs to be replaced, I do have access to a few folks who regularly work on circuit boards that I could probably have help me do a more professional soldering job.

Thank you so much for help so far!! 🙏🏻
 
Your nose can be a good tool when trying to find where a PCBA went bad. The smell of burnt electronics is pretty strong and quite noticeable.

That said, that part doesn't look burnt. It's odd to see it separate like that without any sign of damage. It could still be a swolen capacitor that caused the problem by contacting adjacent parts and causing them to pop out of place.
 
It may be an artifact of the flash, but looking at the rectangular black component labeled "Okaya X2" (?) there seems to be a crumbled section of black plastic on its left side...
 
wxmatt said:
For the life of me, I don’t know how to get that bottom circuit board out so that I can check on the bottom side. I’ve taken out all of the screws, but it seems to be held in by something… The brass pins maybe?

I'm curious about the "2" in a circle, with the arrow next to it. Also there's an item "frame 2" nearby with something mounted there. Can't tell what it is but maybe a fastener of some kind? From other picture I found there is also a "1" in a circle further up that side of the board with a similar silver thing mounted. There's also something with a hex nut near the middle of the board.
 
Upon further review, my piece looks exactly like a part of this "Waffle Plate."

nlspace said:
The Waffle Plate™
CXEyQ5t.jpg

I'm guessing it's pretty likely that I'll be buying a new onboard charger. I talked to an engineer I work with, and when I showed him a picture of the piece of the component and the waffle plate side-by-side, he didn't seem too encouraged about me fixing it.

In a related twist, I posted my pics above on Twitter (@matt_laubhan) so that I had a place where they would be hosted semi-permanently. After tagging them in a reply, Nissan reached out about getting my car towed to the nearest LEAF dealership, which is about 80 miles away. While tempting, my car is already dismantled, and I doubt that they'll spring for the cost of the charger, being that the car is a 2012. I'm leaning toward ordering a new charger, installing it, refilling the coolant, and hoping for the best.
 
Edit: crossed post.

wxmatt said:
When I opened up the onboard charger, shards of black components were rattling around on the back (below the bottom circuit board).
Oh oh.

Upon closer inspection… This is about the most useful piece that fell out.

Ejnvq9FXgAAlAoo
That's from the Waffleplate™. The Mitsubishi iMiEV has a similar (not identical) OBC, also made by Nichicon, and it also uses a Waffleplate™:

CXEyQ5t.jpg


Unfortunately, it's a custom component. People have had to X-ray it to figure out what's inside:

y8TBgB7.jpg


So unfortunately, this OBC is very likely not serviceable unless you have another OBC with a spare Waffleplate™. Or maybe you're really lucky and it's only one diode, so you could find a replacement and mount it on its own heatsink. For what it's worth, failures of the Waffleplate™ are rare (in the iMiEV OBC), so you should feel special :shock:

For the life of me, I don’t know how to get that bottom circuit board out so that I can check on the bottom side. I’ve taken out all of the screws, but it seems to be held in by something… The brass pins maybe?

Yes. You need to desolder every one of those pins. This is only practical with a proper vacuum desoldering station (a cheap on will likely do), and even then some care and/or experience is required. A lot of the time, common repairs can be performed leaving the Waffleplate™ in place. Sadly, it seems that yours may not be one of those cases.

The arrows in the below are for a different purpose, but you can see all the brass pins de-soldered:

Lx8sIFn.png


Perhaps you can take the WafflePlate™ out of the charrger (some of the screws are sneaky, follow the numbering guide), with the PCB still attached, and post a photo of the presumably damaged Waffleplate™ from one or two sides. This should give an indication of whether this OBC can be repaired.

Edit: many of the photos and ideas for the above come from this post: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter.
 
Nubo said:
I'm curious about the "2" in a circle, with the arrow next to it.
It's part of a daisy chain of screws to undo; note it's near a screw. The arrow points you in the direction of the next screw to undo. A nice touch, in the era of "no user serviceable parts inside".

Also there's an item "frame 2" nearby with something mounted there. Can't tell what it is but maybe a fastener of some kind?
I think it's a place where EMI capacitors need to connect to chassis ("frame").
 
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