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Today I tested for myself the recovery method of disconnecting and reconnecting the negative cable on the 12V battery. As advertised, when I reconnected the cable, I heard the THUNK as the lock opened. I plugged in the charging cable, and all is good. I'll be carrying my trusted 10mm box end wrench in the glove compartment now, until the software is updated. I will also add a spreadsheet on my phone to make it easier to keep the history they want.

To the question ". . . have you done anything unique or outside of your normal driving or charging routines?" I would have to answer, "I hit the 92 MPH limit and the caution message was displayed on my dashboard." Anyone else guilty of that? Seems unlikely to be the root cause, but that sticks out in my mind when I think back.
 

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2020 Chevrolet Bolt
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...To the question ". . . have you done anything unique or outside of your normal driving or charging routines?" I would have to answer, "I hit the 92 MPH limit and the caution message was displayed on my dashboard." Anyone else guilty of that? Seems unlikely to be the root cause, but that sticks out in my mind when I think back.
If that truly ends up being the root cause of this issue, then I guess Bolt drivers are an aggressive bunch... :ROFLMAO:
 

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I’ve never hit 92mph and can still see the pin creep out gradually. Very boring usage, really! L2, mostly 30-65mph, charging only when it gets to 25-30% SoC. For me, it takes a few weeks for it to come out to the point of causing a problem. I still think there is an “integral” effect - the sum of many single bit flips (probably only the LSB), slowly pushing the pin out to the max position.

Is it possible that there is an EMI issue with the new batteries?

Personally, I do not find the “carry a socket to reset the battery” to be an acceptable answer from GM. I am a first time GM owner and have defended my choice of a Bolt but if GM or LG (who I believe did the open source software) can’t come up with something after several months of knowing about the issue I will probably be looking to sell and will not be buying another Chevy anytime soon.
 

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You are right. The gradual movement is an indication that a shorter, noisy, inadvertent pulse is being sent to the solenoid instead of a deliberate longer 1 second activation signal.

A software glitch is sending short pulses to the solenoid here and there and it takes multiple pulses for it to move enough to cause the lockout.

That means it’s actually happening more often than we think, just not enough to move the solenoid all in one event.

I doubt it’s an EMC/EMI related issue. It’s possible, but I doubt it.
 

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I'll be carrying my trusted 10mm box end wrench in the glove compartment now, until the software is updated.
Hang on to it even after the software is updated, for at least two reasons:

1. To disconnect the battery if you need a tow. If you don't do this, the car can apply the parking brakes when it senses the wheels rotating.

2. In case the car gets into a funky software state that prevents startup. This happened to me once in 5 years and the 10mm reset got me on my way.

Personally, I do not find the “carry a socket to reset the battery” to be an acceptable answer from GM.
Nope, not acceptable, needs to get fixed.

In the meantime, the brief inconvenience of disconnecting and reconnecting the battery sure beats having to call a tow truck...
 

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Is this issue only happening on MY '19?
As far as I know, that's the case... only 2019 models, and only after the battery replacement I believe...

[edit - I stand corrected about it happening even before battery replacement ]
 

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I just read the PIC6452A bulletin, and one of the questions jumped out at me: Is the vehicle set up with a Charging Schedule or is it set up to Charge Immediately? Yes, I set up off-peak charging schedule a couple of weeks after the battery replacement. not sure if that is a common thread for everyone having issues, but then why would they ask that?

My experience and timeline (all this year 2022) MY 2019:
1/13 Traction battery replaced
1/26 Charging schedule setup
2/26 DC Charge Port Lock stuck #1
3/04 Dealer repaired charge port issue
6/03 DC Charge Port Lock stuck #2

I am going to notify the dealer so they can document the reoccurrence, but I am going to try the "10mm" fix and avoid another service trip for now.

Thanks ALL for all the info!
 

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This charge port lockout condition finally happened to us this morning... Our 2019 had the main battery pack replaced on March 24. Since then, we have charged with our in-garage L2 ChargePoint many times and have not noticed any issue with the port/plug being difficult. We used the info in this thread and disconnected the 12V for a minute and when reconnected heard the satisfying "whirr" of the port latch retracting. The battery disconnect did cause the time, date, and charge level to reset, but everything else on the infotainment system was retained.

The only thing we had done differently recently was running the charge down to about 20% after a further-than-usual road trip over the holiday weekend. We charged to 95% before the trip and after, that was Wednesday and I did not notice any problem with the port/plug latch. We ran it down to about 50% the past couple of days and this morning, Saturday, it would not take the plug.

Thanks to everyone for posting here, it made it quick to find and resolve our problem.

UPDATE: I contacted the EV Concierge and they had NO information and had ZERO knowledge of the TSB. Basically USELESS...
 

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So why is this issue only affecting 2019 Bolt's? Could the design of the charge cord lock/unlock actuator be unique to the 2019? Different designs were used for other model years? Does anyone have another model year they could compare to at least visually? I found a patent from 2016 filed by GM that supersedes previous patents for the actuator, so it may be an evolving design. Anyone interested can take a look and see the history and reference materials.
 

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My guess is that inadvertent pulses are being sent to the lock and the displacement slowly increases over time until the latch impedes the lock and prevents insertion.
Thats an interesting theory that someone else mentioned also. So do we think that pulse is sent upon every charge? I managed to go 3 months between lockups but we only charge like once a week. Has anyone that has experienced multiple lockups correlated that to how many times they charged?
 

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It doesn’t have to be related to charging. It could be ignition cycles, it could be the temperature of the coolant, whether AC is on or not, etc. If it’s not supposed to lock when just L2 charging, then it’s a glitch.

GM uses short pulses to look at if circuits are shorted to battery or ground. It sends them then looks at the shape of the pulse, etc. to decide if it wants to set a fault. Depending on the circuit design, those pulses could be sent too often, on too long, etc. it all depends on the loops.

If someone wanted to instrument their car and monitor it 24/7 for unusual patterns, they might trace it down, the that’s GM’s job (or whatever supplier makes the parts involved). I’ve seen simple Software bugs take months to solve that literally only happen under very rare conditions. The fix was easy. Finding the root cause was hard. There not teams working on them as much as you’d think.
 

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Oops -- it happened again. Just this week. First time since back in the winter when I posted to this forum. As I have not been using the app to precondition my car, this blows my theory that it was in someway related to use of the app or preconditioning the car (since discredited by others). Let me add my thank you to those who shared the solution -- disconnect battery cable from the negative terminal. This forum is so useful. Have a good summer, hope the folks at GM can figure this out. It is annoying and detracts from what is otherwise a high quality product.
 

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Perhaps it has something to do with the battery monitoring system since this didn't happen before the replacements. Maybe it's more likely if you let the car finish monitoring after charging or vice versa. That sort of thing. Again, it seems odd that they can't pin this down - the engineers know how the software has changed and would also be aware of any hardware differences in the 2019. (It hasn't happened to me yet but I do have the wrench).
 

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You folks are lifesavers!

Just to add my info. 2019 Bolt. Had the 12v battery replaced two weeks after new purchase. Traction battery replaced on 4/22/2022. First occurrence charging lock problem yesterday 6/8/2022. Chargepoint Home charger wouldn't engage. State of charge was a bit lower than usual - 63 miles / 33%. Occasional DCFC and L1 destination charging, but mostly at home. No battery preconditioning or charge scheduling. FWIW, haven't gone over 92 MPH :)

The 12v battery fix worked (1 minute disconnect), but it apparently reset the Bolt clock, so it indicated 22 hours to charge. (LightningEV noted this back in post #223) It's actually charging at the normal speed. Haven't run the car to see if the reset changed any other settings.

I'm lucky to have a dependable dealer, but I'll wait for an authorized fix before I take it in.
 

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Thanks. I thought about trying this, but I have a pretty good dealer and I wanted them to see it themselves. Perhaps if enough of us make a pest of ourselves, they will pester GM into correcting the problem 🙃. Excuse my ignorance and not being familiar with the car jargon, but what is a TSB? Is it a service update for dealers & repair shops? Can I find it somewhere?
Just had the J1772 locked out for the fourth time, disconnecting the 12VDC negative cable did the trick, thanks very much for that idea ! The first three times I took it to the dealer, they downloaded a software patch and told me it was not a permanent fix and they claimed the problem was only with 2019 Bolts which had a battery replacement. I keep asking the dealer, but no fix from GM yet. Spent an hour on the phone with GM today, finally reached someone who would generate a customer complaint, I should hear back within a week, will report back if anything helpful occurs.
 

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Just had the J1772 locked out for the fourth time, disconnecting the 12VDC negative cable did the trick, thanks very much for that idea ! The first three times I took it to the dealer, they downloaded a software patch and told me it was not a permanent fix and they claimed the problem was only with 2019 Bolts which had a battery replacement. I keep asking the dealer, but no fix from GM yet. Spent an hour on the phone with GM today, finally reached someone who would generate a customer complaint, I should hear back within a week, will report back if anything helpful occurs.
Demand a trade/swap to a 2023 Bolt. ;)
 
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