is it time to scrap my Nissan leaf?

[Danceman]

Hello Members,

We have owned a Nissan Leaf from new in 2011.
It has 74000 miles on the clock, and has had its ups and downs over the years. The car is still in overall great condition and has always been dealer serviced.
The range has dropped to about 32 miles but we can manage on that.
We have only ever charged the car on the home charging unit on the drive.

Four months ago the car would not charge using the home charger. We also tried the original cable supplied with the car and it still would not charge.

We managed to get the car over to the garage.
After 3 days they said there was no problem the car was charging okay.
However they were using their fast charging unit, not a home charge unit. They tried the original cable supplied with the car and it would not charge.

To sort the problem they said that we needed to change the N/STK modulator assembly at a cost of £2225.86
We reckoned the car was worth about £6k in good order so reluctantly ordered the part. After waiting six weeks for the part to be shipped over and fitted the dealer said they had installed the modulator. Unfortunately it had also blown the next part. Now the repairs to cost a total £3400.

We very reluctantly agreed because as I mentioned the car is in overall great shape.

Move on another 8 weeks, both parts fitted and we are informed that the car is ready to return to us. We got a call the night before we were due to pick up to say they have hit another problem. The parts they fitted have not sorted the charging problem.

The latest solution they offered was for us to take it to the garage every day to get a fast charge! Due to the distance home we would then not have enough range to get back to the garage.

it seems stupid to scrap a car that works, but can't be charged at home. The garage seem to be at a loss of what to do.

Has anyone come across a similar problem or recommend a solution?

Regards
Derek

 

[solartim]

Our 2011 battery failed at 70k. We had internal resistance error codes that I saw with Leafspy. I would think you have the same problem. Good luck, it's an expensive repair however you go about it. There are several threads discussing the process, like this one below. We got lucky with a clearance sale on older batteries by Nissan, otherwise probably would have scrapped it.

Is the fast charger Chadmeo or just a 240 V level 2?

 

[91040]

Apologies if my ignorance of the British meaning of “modulator” negates the following.

Check to see if this is the diode failure in your onboard charger. There are threads and a video posted on this forum.

 

[Stanton]

Regardless of the specifics of this car, this dealer seems to be incompetent. I think you have 2 issues if you want to keep the car:
1) fix whatever problem is causing it not to charge (assuming this is only L1/L2), and
2) you really need a new battery pack (my opinion)
Both of these issues are expensive, but I would start with trying to salvage/reclaim whatever $ you have spent with this dealer (and maybe Nissan can help--but that's just a guess). At this point, you don't even know if the problem lies within the battery pack, but replacing that would obviously fix the problem if true.
Bottom line: you need an accurate diagnosis of the problem before doing anything (and I would have a different dealer/location do it).

 

[coulomb]

To sort the problem they said that we needed to change the N/STK modulator assembly at a cost of £2225.86

The "N/STK" probably stands for "non-stock" or similar. I think that "modulator" is short for an "Illudium Q-36 explosive space modulator", as designed by cartoon character Marvin the Martian, for planet busting:

No disrespect intended, but unless badly mis-remembered, "modulator" really sounds like a term that a dealer might make up to sound technical. The closest thing in an EV might be the motor controller, or I could imagine the on-board charger (which could have been at fault here) could at a stretch be called a "modulator" of sorts. But then what was the even more expensive part? The only other part that makes sense would be the Vehicle Control Module (VCM). Oh wait, that might conceivably be the "modulator", and the other part that was replaced might be the on-board charger.

It would be good to know if the on-board charger was replaced, since the diode mentioned in an earlier post lives inside the charger. With a new charger, there is no point suspecting the diode. Also, the on-board charger is the main part that is unique to AC charging (level 1 or level 2 charging). If only you were interested in electronics, the original of those two parts are valuable to DIY repairers, especially the on-board charger. What's left after that is basically the J1772 charging socket and wiring. Or perhaps a high voltage fuse, but that should have been checked very early in the diagnosis process. I don't actually believe that your dealer's technicians are incompetent, just that they aren't trained for out-of-the-ordinary repair work. It really helps if they happen to have a technician with more electronics knowledge than is required of a dealership. That applies almost as much for ICE vehicles as it does for EVs, these days.

 

[Danceman]

Hi all

Thank you very much for your reply's to the post. They are very much appreciated.
Unfortunately I aren't very technical with electrics so would not be very confident to investigate myself, but will speak with the garage.

The charging port has not been replaced to my knowledge and the modulator they have changed is referred to has a part number N237D03ND0D

The car will charge fine on a Chademo socket. is there an adaptor for a J1722 to then use the Chademo socket?

Your replies are very much appreciated.

 

[coulomb]

The car will charge fine on a Chademo socket. is there an adaptor for a J1722 to then use the Chademo socket?

Not inexpensively. The CHAdeMO port bypasses the on-board charger, so you need an actual external charger to use that port. What most people call a charger is really an EVSE, Electric Vehicle Service Equipment. In reality, an EVSE is a glorified extension cord, there is no power conversion, as in a real charger.

You actually can charge at home through the CHAdeMO port, if you buy what is essentially a small fast charger. Companies like Setec make a 10kW model, I think you can throttle it and plug it into single phase power, I'm not sure. But unless things have changed in the last year or so, these would cost more than your older car is worth.

There are also bidirectional CHAdeMO devices now; one was recently approved for use in Australia (the Wallbox Quasar). These would be more expensive again, but you might find more value with something that can power your house in a blackout. I'm thinking that you won't have the appetite to spend more money at this point. Also, these are all CHAdeMO not CCS (the more recent fast charging standard) and your next EV is very likely to be CCS.

So in summary: no, that's likely not a solution for your situation.

 

[nlspace]

If you talk to the dealer service department again, ask them for a listing of the codes that showed up on the Consult tool. These would be the Diagnostic Trouble Codes that point to the problem area and define the necessary troubleshooting steps in the Factory Service Manual. If you can post those codes up here in the forum then we might be able to help identify the problem.

Also tell them you want your old (probably not broken) parts back, or at least take a picture of them and post it up here. Your old parts will have value to someone trying to make repairs, and you can recover some of your cost$.

 

[coulomb]

Sigh. Time for me to eat humble pie. It seems that "modulator" is an actual word sometimes (rarely?) used to describe the VCM, or Vehicle Control Module:

From https://parts.performancenissan.com/p/Nissan__Leaf/Engine-Control-Unit-Modulator-EV-VCM-Powertrain-Control-Module-Transmission-Inverter-Control-Module/89463218/237D0-3NA1E.html .

the modulator they have changed is referred to has a part number N237D03ND0D

So this is almost certainly the VCM, as above.

It would be great to know whether the on-board charger was replaced. It's a much larger unit; the VCM fits behind the glove box (at least in left hand drive countries).

The part number should start with 296A0 (zero, not oh); the last part of the part number varies with revision. I included the price (in US$) in this one, to give you an idea of what might have been possible. I believe that these are supposed to be brand new. From https://parts.performancenissan.com/p/Nissan__Leaf/Drive-Motor-Battery-Pack-Charger/89812120/296A0-3NA8A.html .

 

[goldbrick]

Modulation is certainly a word I've heard used in an electrical engineering context but never for a motor controller. OTOH, I guess it is a sort of frequency modulated driver circuit so maybe it makes sense.

 

[cwerdna]

I know of https://en.wikipedia.org/wiki/Variable-frequency_drive and also PWM (https://www.tomshardware.com/reviews/glossary-pwm-pulse-width-modulation-definition,5888.html).

 

[lorenfb]

Modulation is certainly a word I've heard used in an electrical engineering context but never for a motor controller.

Typical PWM use for low torque applications, e.g. a vehicle HVAC fan speed controller.

OTOH, I guess it is a sort of frequency modulated driver circuit so maybe it makes sense.

And for a BEV motor controller; https://en.engineering-solutions.ru/motorcontrol/pmsm/

With reference to the Leaf's VCM; http://www.nissantechnicianinfo.mobi/htmlversions/2013_EV_Special/ePower_Train.html

 

[coulomb]

Modulation is certainly a word I've heard used in an electrical engineering context

Yes, that's true, in the context of a radio transmitter perhaps. Also modems and other signal processing gear. Of course, the "mod" part of "modem" comes from the word "modulator" (as in a modem is a modulator-demodulator). It just seemed so jarring in the context of an electric vehicle, especially the AC charging process.

Perhaps it goes back to the early days of ECUs, where an ECU might have modulated the fuel-air mixture in the carburettor through some actuator or fuel injector system; I'm guessing wildly here.

but never for a motor controller. OTOH, I guess it is a sort of frequency modulated driver circuit so maybe it makes sense.

Sure, but the VCM in the glove box isn't the motor controller (which is under the hood). It's maybe giving high level directions, like "battery low, limit power to 25%", but it's not directly modulating the amplitude, frequency, or phase of any sine waves.

With respect to AC charging, the VCM's role seems to be more starting and stopping or preventing charging than detailed control like voltage and current. I'd say that's the only reason it's in the decision tree for diagnosing AC charging problems.

[ Edit: added "directly". ]