2019 Leaf won't start

I bought a 2019 Leaf Plus back in June. This morning when I went out to start the car, the accessories all went on, but the drive itself won't start. It gives me a warning saying that the EV system can't restart and needs servicing. I've tried pushing the brake (firmly) and power button several times.

A few potential causes--

1. It snowed and got icy last night here in Denver, and this is really the first night that I've tried to drive when it is cold. But would that cause this problem?

2. I was lightly rear-ended on my way home last night. I turned the car off while we exchanged info and it restarted fine then. But I don't know if that could have affected the EV system in some way.

3. Some combo of #1 and #2?

I've called Roadside Assistance and they said it will need to be towed to the dealer, which is a pain. Any quick fixes I can try to see if I can get it going by myself while I wait?

If you have LeafSpy Pro you could try to read and/or clear any trouble codes. If it was me though, I would leave the car alone since if there is expensive damage to the EV system from the collision you will want to document that as much as possible for any insurance claims.

Check the 12V battery, measure the voltage with everything OFF. Chances are the cold weather has caused an under-charged aux battery to not perform. Separate charging of the aux battery is a good idea to keep it fully charged and reduce desulfation. The cars charging system is not sufficient.

goldbrick said:

If you have LeafSpy Pro you could try to read and/or clear any trouble codes. If it was me though, I would leave the car alone since if there is expensive damage to the EV system from the collision you will want to document that as much as possible for any insurance claims.

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Thanks, goldbrick. I do not have LeafSpy Pro--I've seen it mentioned here a lot, but have not felt the need to get it until now. I understand that in addition to the app I need to an adapter of some sort to make that work, right?

I ended up getting it towed to the dealership, so hopefully will find out what is happening quickly. Still, frustrating to have this problem only 5 months in.

If there is no crash damage that caused this, they will likely find a weak 12 volt battery. They will charge or replace it. Do you leave the car plugged in for many hours, on a regular basis, after charging ends?

LeftieBiker said:

If there is no crash damage that caused this, they will likely find a weak 12 volt battery. They will charge or replace it. Do you leave the car plugged in for many hours, on a regular basis, after charging ends?

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I'm a bit confused about how the 12 volt battery can get so weak so quickly (only 5 months) and understanding what things pull from the 12V as opposed to the EV system.

I generally only charge using L2 charging at work and don't ever charge it to 100% or leave it plugged in when it is not charging.

The car does sit outside at night, so I've been debating about whether I need to plug it in at night, though, to help with battery temp as winter approaches--should I be doing that?

LeafSpyPro is just an app you buy for either IOS or Android. You will need a bluetooth or wifi capable OBDII adapter as well. Some OBDII adapters work while others don't (depends on chipset used I think....) so search around here for recommendations for which adapter to buy. The adapter is about $20 and LeafSpyPro is about $10. It's not essential but it's a nice thing to have for various things.

A week 12V battery will cause all sorts of havoc on a Leaf. The early year models had a problem whereby the 12V battery charge level wasn't managed well and led to all sorts of problems. There was also a telematics issue I think that could drain the 12V battery on some models/years. AFAIK, none of these problems affect the 2019 model. You could still have a defective or dis-charged 12V battery though.

As far as what runs on 12V, it's all the normal stuff on any car: wipers, blower motors, internal and external lights, radio, nav system, etc. On a Leaf there is also a bunch of control electronics that run on 12V that manage all the computers on the car, the battery charger, etc. If you normally shut the car 'off' when parked I don't think you have to worry about the 12V battery unless it is defective.

I'm not sure of all the details about cold weather but if you have the 'all weather package' you should be set. There is a battery heater that runs off the main, high voltage, battery that keeps the pack from freezing. I think this only kicks on when the battery temp is very low (like 0F or even below) so that will be a rare event on the front range. It takes a long time for the battery to cool down so it tends to track the average temperature of the last 24 hours or so and it rarely gets that cold here. If the predicted high temp was something like -5F for a few days, that would be the time to worry about keeping the battery charged up. Otherwise, I wouldn't worry about it.

Be sure to let us know what you hear from the dealer. It's always good to close the loop on these types of threads to spread the knowledge.

zmountin said:

I'm a bit confused about how the 12 volt battery can get so weak so quickly (only 5 months) and understanding what things pull from the 12V as opposed to the EV system.

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The 2011 and 2012 model year cars had a problem with the 12V battery going discharged when the car was plugged in and not charging for days. The DC to DC converter that charges the 12V battery off the traction battery didn't run in these early cars when the car was plugged in.

Older cars had problems with the TCU module, used for remote climate control, charging and such. These problems could drain the 12V battery overnight.

A few other cars have had various weird problems that were resolved by replacing the 12 V battery.

Some cars have had problems from leaving OBD dongles in place for long periods of time.

The LEAF's 12V charging system is different than an ICE, and some can't adjust their thinking. The voltages are lower by design. ICE cars typically overcharge the 12V battery, and the lead acid battery is very tolerant of overcharge.

Take all of the above, and mix it together. Then understand why one of the first questions that someone with a problem gets is "how is your 12V battery?" And so far, the results are that this question diagnoses enough weird problems so that people keep doing it.

^+1

And to the OP, is it possible the impact of the collision moved the battery or one of the cables so that it shorted out to the frame of the car and discharged? I would expect to see smoke if the + terminal of the battery contacted bare metal but perhaps it was resting against a painted surface or something and discharged slower.

In any event, please do update us all with what you discover.

The 2011 and 2012 model year cars had a problem with the 12V battery going discharged when the car was plugged in and not charging for days.

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The issue runs through the 2013 model year as well.

goldbrick said:

^+1

And to the OP, is it possible the impact of the collision moved the battery or one of the cables so that it shorted out to the frame of the car and discharged? I would expect to see smoke if the + terminal of the battery contacted bare metal but perhaps it was resting against a painted surface or something and discharged slower.

In any event, please do update us all with what you discover.

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Or it's possible that an ECU (electronic module or modules) failed to power down (enter "sleep" mode) and drained the 12V battery after the
accident, a similar situation that occurred when some of us had the TCU upgrade and had over night dead 12V batteries because the TCU
failed to power-down after use.

zmountin said:

LeftieBiker said:

If there is no crash damage that caused this, they will likely find a weak 12 volt battery. They will charge or replace it. Do you leave the car plugged in for many hours, on a regular basis, after charging ends?

Click to expand...

I'm a bit confused about how the 12 volt battery can get so weak so quickly (only 5 months) and understanding what things pull from the 12V as opposed to the EV system.

I generally only charge using L2 charging at work and don't ever charge it to 100% or leave it plugged in when it is not charging.

The car does sit outside at night, so I've been debating about whether I need to plug it in at night, though, to help with battery temp as winter approaches--should I be doing that?

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Anecdotally my then 3-4 month 2018 SL was completely dead sitting my garage & that ended up being a dead 12V battery. Once I recharged the car operated normally & I didn't find any interior lights left on and that scenario hasn't presented itself since so I have moved on.

I realize your situation is different but it seems like all these high tech cars can sometimes BSOD for like of a better descriptor.

It is a bit unclear what is going on. Here's what the dealership explained, but he also seemed a bit uncertain: The EV battery is split into four functional parts (cells?). One of those four parts is showing up as overcharging, but they aren't sure why yet. They have to remove the whole battery pack and see if they can tell if there is any damage. But, that is going to take a while. I also don't know if this dealership has a ton of experience with EVs, which I wish I had realized before.

They didn't think it was caused by the accident, but didn't know until they fully took everything apart.

The good thing is that they say it will all be covered by warranty and have provided a rental in the meantime. When I learn more, I'll let people know.

Did you charge the car after the accident ?

The dealership description makes it sound like one part of the battery discharged into another part. I don't know if that is even electrically possible but you may owe the person that bumped into you a cup of java for exposing a manufacturing defect if true.

I really have no idea. Good luck, and please let us know how things turn out.

goldbrick said:

is it possible the impact of the collision moved the battery or one of the cables so that it shorted out to the frame of the car and discharged?

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It doesn't have to discharge the battery, just have more than a small amount of electrical leakage to chassis. Part of the tTok-tTok-tTok sound when a car tries to go to ready mode (ready mode dash icon is a car with a double ended arrow under it), is checking for leakage to chassis, i.e. an isolation test. While it's technically possible for the car to drive in that situation, car makers (or regulators) don't allow it because it means that touching nearly any part of the battery becomes lethal, and the battery is now only one partial short away from a slow or rapid discharge, which could lead to a fire or damaging the battery through excessive discharge. Best to get the leakage fixed now, or so the logic seems to go.

SageBrush said:

Did you charge the car after the accident ?

The dealership description makes it sound like one part of the battery discharged into another part. I don't know if that is even electrically possible but you may owe the person that bumped into you a cup of java for exposing a manufacturing defect if true.

I really have no idea. Good luck, and please let us know how things turn out.

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No, no charging after the accident. Just came home and the car sat outside overnight in freezing rain/snow.

The other potential variable is that I used a CHAdeMO charger for the first time this week, so I don't know if that perhaps triggered something. But, that was also several days prior to the problem.

The service department should rule out the simple things first before opening the pack.

i had a no-start condition in a 2012 that had set outside for 3 weeks; towed to the dealer and they run tests and pronounce the pack dead and needing replacement. i got the car back and checked the 12V, which was reading very low. Charged it up, then charged the car with L2 EV.SE, it started right up. The Nissan 12V aux was only 17 months old, yet sulfated beyond point of recovery. They wouldn't honor the aux warranty, yet the car was in their shop and they didn't find the problem--so how much do they know about these cars anyway?

My point being that your story points toward a discharged 12V aux rather than an internal pack issue--did they perform a load test on the aux battery to rule it out? i doubt it.

Common sense says that a fender bender that didn't discharge the air bags isn't going to be enough damage to affect the pack. Many packs have been pulled out of wrecked cars with no damage.

A weak aux battery can cause all sort of DTCs and other faults, mostly phantom faults when the 12V issue is corrected.

nlspace said:

The service department should rule out the simple things first before opening the pack.

i had a no-start condition in a 2012 that had set outside for 3 weeks; towed to the dealer and they run tests and pronounce the pack dead and needing replacement. i got the car back and checked the 12V, which was reading very low. Charged it up, then charged the car with L2 EV.SE, it started right up. The Nissan 12V aux was only 17 months old, yet sulfated beyond point of recovery. They wouldn't honor the aux warranty, yet the car was in their shop and they didn't find the problem--so how much do they know about these cars anyway?

My point being that your story points toward a discharged 12V aux rather than an internal pack issue--did they perform a load test on the aux battery to rule it out? i doubt it.

Common sense says that a fender bender that didn't discharge the air bags isn't going to be enough damage to affect the pack. Many packs have been pulled out of wrecked cars with no damage.

A weak aux battery can cause all sort of DTCs and other faults, mostly phantom faults when the 12V issue is corrected.

Click to expand...

Agreed. Disconnect the 12V battery from the car, charge it with an external charger, verify with a multimeter that it shows at least 12.4V. If it does not, replace it. When you replace it, use an AGM style battery--will cost more but avoid problems like this in the future.

Then reconnect the car and try to use it. 90% chance your problems go away.