AC charging does not work, 2012 Leaf in Sweden

[coulomb]

the pilot-ground resistance also showed the similar (OL / Mega Ohm) range (similar to test on the leads of D547 diode on the board) and I equated Mega Ohm with open loop, which seems to be wrong.

Yes. I never measure a diode with the resistance range; I just tried it on my Fluke 87 III and it measured over a megaohm as well. I used another meter to measure the voltage: 0.64V. That's barely enough to cause a small diode to conduct (power diodes conduct harder, at 0.4V or even 0.38V). So it looks like a high resistance. I suspect that modern multimeters all do this, to minimise the effect of diodes elsewhere in the circuit. If I force the range to be ohms instead of megaohms (e.g. press the button for the buzzer function), the voltage rises to over 1.2V. But on that range, a small diode reads open circuit.

The diode range on a multimeter is different. It allows the voltage to rise to over 3.0V (needed for blue LEDs to conduct), and reports the voltage that the diode drops with a relatively constant ~1mA current, rather than treating the device under test as a resistor. So the 481 you measured on a diode test range probably represents 481 mV (0.481V). That's actually a little lower than I'd expect for a small signal silicon diode. I'd expect at least 0.5V. My Fluke read 0.603V across a leaded 1N914 small signal diode, the other multimeter 0.529V. The latter probably tests at a lower current.

The cable that I use is similar to this:

Ah! Of course, 2012 Leafs were all J1772, even in Europe. Leafs would have switched to type 2 around the time of the switch to second generation Leafs around 2017.

When I said I suspected the wiring, I meant the wiring between the J1772 socket and the On Board Charrger. But since the J1772 pilot to earth measures similarly to the actual diode, that wiring is no longer suspect.

So: back to the charrger innards.

 

[nlspace]

The DTC doesn't narrow in on whether the issue is the pilot signal or the AC mains until the mechanic uses the Consult tool to determine which type of fault. But his options are limited to replace a bad EVSE or replace the entire OBC.

The pilot is on the upper control board and the diode D547 has been a culprit in some vehicles.

The AC mains comes in at the upper right corner of the lower power board.

There are two fuses on the AC mains circuit that should be checked, and inspect the 3 transient surge suppressors (look like black disks or coins) for damage.

Issues with the AC mains can involve any of the components in that fenced region with the 3 tall white ceramic resistors, filter capacitors, and the AC mains relay. The relay gets its drive signal from the upper control board once all the starting conditions between the OBC, VCU and EVSE are good.

 

[nlspace]

i just went out and plugged in my EVSE cable and noted this sequence: i heard 1 beep and a relay clack and then the first blue light came on and off, then i heard 2 confirmation beeps and multiple relay clacks and the blue light came on again and began blinking as charging started.

 

[MikeEcho]

There is thread on here with a good picture of a blown diode on the power board, but i couldn't find it right now.

The debris on the faston connector of the blue wire may be from this diode located below the black capacitor with the gray sealant globbed along its side and edge, and above the ("L" for blue) faston tab and resistor string of R107-R110 as shown in your picture.

BTW... this time I tested the diode using the MM's diode function and it was Open Loop in either direction.

Hi nlspace, you were spot on sir! I went and took these photos of the diode, that comes at the end of my post.

Now my challenges are
1. To find a and order a replacement diode for the toasted diode.
2. Figure out a way of removing the lower board from the OBC (if possible, without touching coolant lines and removing OBC from the car).

BTW... it is the D211 Diode as mentioned here:

Ok, opened up the charger tonight and when I opened it I smelt the magic white smoke had been released, there is a blown diode, on the power board D211. Now I have to figure out the value for the diode, anybody have any ideas. Of course this may not be the only problem, but its worth giving it a try to replace. See below for board images

http://imageshack.com/a/img924/3037/vj9wDl.jpg
http://imageshack.com/a/img922/4954/fpbBQX.jpg

 

[nlspace]

Just to the right of the right hand white solder stripe is a screw with circled "1" next to it. That is the starting point for the board removal, then follow the arrows to the numbered screws to follow the sequence. The center has a hex bolt not sure if it is numbered, and all the hex-sided standoffs will need to be unscrewed. When all are removed than the entire power board with the attached waffle plate can come out of the OBC; mark the wire color and locations of the faston tabs. The tabs have a release latch internally, hold the wire down then slide the white cover up to engage the release, then the connector will easily slide up. If you don't do this you will cuss.

i think the diode is from SHINDENGEN, a 4A diode rated 600V. "4FV 60" marking code.
It has part number D4F60 at Mouser:
https://www.mouser.com/ProductDetai...r&utm_source=findchips&utm_content=Shindengen


This might show some of the circled number locations, the center bolt and the hex standoffs.

 

[MikeEcho]

Thanks... I ordered the "D4F60" from Mouser (should arrive Monday-Wednesday, it is with FedEx now) and managed to pull out the lower board. I checked the fuses and they were OK. I wonder if I could assume that the other components are OK, or should I test some other components on the board.

The fact that I could remove the lower board without removing the OBC (and dealing with coolant lines) was priceless, since I no longer have access to my private indoor garage and I have to work on the Leaf while it is parked at a public parking.

I also wonder what causes this mode of failure? I had removed the charging cable multiple times from [first the car, then] the charging pole after the 80% charging limit was reached and the car had stopped charging, but the charging pole was not turned off (by blipping the RFID card). Obviously I will be more "cautious" with the On Board Chargers if I manage to repair it this time.

 

[nlspace]

By all means inspect the board and components for signs of charring, burning, sparking, arcing, etc.

My pet theory of charger failures involves a sudden, uncontrolled or un-commanded loss of power, either the AC mains power, or some low level DC power supply for the control board, such as the 12V from the aux battery.

There is substantial energy in the magnetic fields of numerous inductors and transformers which create large voltage spikes if the fields suddenly collapse.

For this reason the OBC must shut off the charging current when the release button is pressed before the handle can be withdrawn. This involves coordination with the EVCU for the relay and contactor controls, etc. That is to say, don't just jerk the AC cord out of the wall or disconnect from adapter cable while the OBC is active (when the 3 blue dash light are lit).

A sudden loss of AC mains, accidental or intentional, is likely to cause a failure such as yours, but a dropout of the 12V battery could also let relays open and cause the same effect.

In normal operations the 600V rating of the 4A diode likely has margin for the design point, but an abnormal event could cause the voltage there to exceed the rating at which point it failed.

[edit: with the board out you could check/verify that there are no shorts or opens in the waffle plate circuits using the diode check function of your DMM. There is a diagram available if i can remember where it is located.

Waffle plate and Faston wiring colors (Citroen CZero)

Diode voltage drops:

Ref: More details than you ever want to know about OBCs and failures here, OBC Troubleshooting and Repair

 

[MikeEcho]

I did not test other components, and unfortunately, after changing the D211, the charging does not work. I am thinking of sourcing a second hand or new OBC. Apparently there is not anything available in Scandinavian salvage yards, and buying brand new from USA seems to be the most economic choice, even though it would cost around $2000 after shipping and import taxes.
I would be glad if someone let me know if you know about a seller in EU with a better deal, but so far those that I have found cost about $3000. It is a bit rich for a car worth $9000 but I don't think I have many other choices.

 

[nlspace]

Sorry to hear that it didn't work.

it's very advanced troubleshooting to get down into the board level components and requires a very detailed inspection. For example, one of those 3 white ceramic resistors has an internal fuse and it sometimes cracks the case when it blows.

There are numerous checks of the power board sent over the cable to the control board, but if the power supplies of the control board are not working, then it won't start, etc.

check with dala the great, he might have some leads on getting an OBC.

 

[MikeEcho]

Last week I bought a second hand 296A0 3NA3A (2011 model) from ebay UK (the item was in Lithuania... but I paid VAT) and received it on Monday. I installed it the same day and now the car works and charges. I am planning to poke around the circuit board of the failed charger with a ESR meter to find out if a capacitor needed replacement but obviously it will be more out of curiosity and not a need.

All in all it was an eye opener to me; as I had over-estimated the longevity and ease of repair of the electric cars. One can say that an ICE car (after 120 years of research and development) has fewer parts that are so vulnerable to fail at 50 000 km and so costly to repair [dealership asking about $3000 just for the part , and this part was so rare and expensive also on the second hand market].
I knew before my purchase that I should buy a 2013 and higher model, but in Sweden they advertise Sep 2012 cars as 2013 and this misled me into picking this particular car; however I was rather content with it so far but I see that the charging system is both faster (6.6 kW) and more robust in the 2013+ Leafs.

 

[Daniel270766]

Last week I bought a second hand 296A0 3NA3A (2011 model) from ebay UK (the item was in Lithuania... but I paid VAT) and received it on Monday. I installed it the same day and now the car works and charges. I am planning to poke around the circuit board of the failed charger with a ESR meter to find out if a capacitor needed replacement but obviously it will be more out of curiosity and not a need.

All in all it was an eye opener to me; as I had over-estimated the longevity and ease of repair of the electric cars. One can say that an ICE car (after 120 years of research and development) has fewer parts that are so vulnerable to fail at 50 000 km and so costly to repair [dealership asking about $3000 just for the part , and this part was so rare and expensive also on the second hand market].
I knew before my purchase that I should buy a 2013 and higher model, but in Sweden they advertise Sep 2012 cars as 2013 and this misled me into picking this particular car; however I was rather content with it so far but I see that the charging system is both faster (6.6 kW) and more robust in the 2013+ Leafs.

Hi Mike,

Please would it be possible for you to take some photos of the disassembly process and anything that you find? I work for an aftermarket parts manufacturer and we are currently looking to create commonly failing parts for electric vehicles. As you say the alternatives to these are expensive and often it's a dealer only option (this is where we would come in).

What would you be doing with the part once you have disassembled it?

 

[MikeEcho]

There is a good guide with pictures here:
https://www.speakev.com/threads/a-guide-to-changing-the-onboard-charger-on-the-nissan-leaf.160015/

I add that:
1. It is important to print and follow the guideline for removing the High voltage connector from the OBC. the big connector has 3 tabs (on top and side) that should be pushed-pulled in a correct order to unlock the connector.
2. I skipped removing the connector from battery. (I only removed the middle safety lock).
3. I tried to remove the coolant connector without removing the black plastic shield under the car, (as one can reach them from the holes on the shield) but I could not apply sufficient force to remove the rubber tubes off. Some bolts were rusted and sheared when I removed them.
4. I initially had just refilled the radiator, but when I started charging, I heard a noise from a container higher up than the radiator, and realized that it was running empty, so I refilled that multiple times until all the air in the system was removed.
5. I don't know what to do with the old (broken) charger. I have seen people selling broken OBC for ~$50 online, ..., for now I will let it sleep in my small storage.

 

[MikeEcho]

With the peace of mind that comes from having a repaired car, I had a look again on my board (and after reading Sjalabais' post on speakev.com) and decided that the gray material next to the OKAYA LE335 capacitor is not a glue to fix the capacitor to the board, but the electrolyte that has leaked from it (and solidified like very hard chewing gum).

I think I will replace this CAP before packing my OBC and keep it as a backup. Unfortunately I will not be able to test the success of this repair.

 

[nlspace]

That AC filter capacitor is a common failure in the OBC. That's why its good idea to show pictures of the entire board such as i posted earlier. There you can see that capacitor without the gray stuffing that has leaked out. You should inspect the white ceramic resistors carefully and the AC input relay also.

 

[MikeEcho]

That AC filter capacitor is a common failure in the OBC. That's why its good idea to show pictures of the entire board such as i posted earlier. There you can see that capacitor without the gray stuffing that has leaked out. You should inspect the white ceramic resistors carefully and the AC input relay also.

Thanks, I think I need to remove the waffle plate to check out these resistors and also take out the failed caps.
I think the LE105 (1uF Okaya capacitor) [and probably the relay next to it] is also in trouble:

I also took a top photo from the whole board.

 

[nlspace]

Has the black 1uF capacitor also cracked and leaked?

There are diode checks that you can make on the solder joints to the waffle plate to check if it is damaged.

Also you can measure if the white ceramic resistors are open by measuring resistance from the faston tab for the Neutral (blue wire) to the N solder joint junction (4 pins) of the waffle plate. Should get about 15 Ohms if they are all good. If you get nothing then the the first resistor with green lettering on it has an internal fuse that may have blown.

An easy point to clip on is the ends of the R101 resistor next to the inductors, one end goes to the N junction and the other side goes to the L junction of the waffle plate solder joints. The leads for the first ceramic can be reached with a long skinny test clip. The blue lettering devices are pure resistors with no fuse.

And it is possible to activate the relay to check continuity.

The black potting in the fenced areas is easy to remove with a wooden spudger stick.

Is there some damage in the potted area between the two orange capacitors on the left side in your picture over by fuse F102? There is a resistor buried under the potting in that section of the output filter that you can measure from the bottom side.

 

[MikeEcho]

Has the black 1uF capacitor also cracked and leaked?

yes, I see some small amount of dark material coming out of its corner (towards the copper coil). Also there is black soot on the white resistors.

There are diode checks that you can make on the solder joints to the waffle plate to check if it is damaged.

Also you can measure if the white ceramic resistors are open by measuring resistance from the faston tab for the Neutral (blue wire) to the N solder joint junction (4 pins) of the waffle plate. Should get about 15 Ohms if they are all good. If you get nothing then the the first resistor with green lettering on it has an internal fuse that may have blown.

I did this test and I think this resistor chain is open.

 

[nlspace]

See my post again--made some edits for checking the fused resistor. Also the resistor on the output filter?

 

[MikeEcho]

sorry, I have been too busy in recent days... I will get back to you in the coming weeks. I understand that it is rude to drop out of the forum once the problem is fixed and you got all the free guidance.

 

[Uttie]

Hi mikeEcho, i am having problems with ac charging too, i also live in sweden and have a 2012 leaf. But mine makes a strange sound from the motor area when i connect the 230v charger, i uploaded it to youtube. Did yours sound anything like this?
My car has not been able to charge from public charging points for quite a while now btw.

https://youtube.com/shorts/HFmDHEmQsYo?feature=share