[BillyH]

Just got the U3636 error yesterday on my 2021 EV at 65000 miles. Software update was about 10000 miles ago and the 80% limit went away as scheduled. Earliest appointment I could find around me with an EV tech is in 5 days. Bumper to bumper warranty has expired and it's $180 diagnostic fee unless it's determined to be a warranty repair. My question is if my error can be fixed with another software update will that be covered under the 8 year/100k battery warranty? Obviously if it's a new battery it would be covered, but I'll be pretty annoyed if I have to pay because their remedy software is too aggressive with identifying bad batteries. Thanks.

Update: will be needing a new battery estimated at 4-6 weeks, at least it's fully covered under the warranty...

Update 2: Still waiting for a replacement battery 12 weeks later. Car went in the end of Jan and it is now the end of April. Dealer has been good about calling each week with no updated delivery date 🤦

 

[jahorsle]

And, I’ve also joined the club… We shall see what the dealer says.

Date: 01/28/24
Diagnostic Code: U3636
Miles driven before detection: 15,000+
How long to get new pack: At dealer for diagnostics
Car Build Date: 07/20
Notes: Car purchased used in 4/2024. Original monitoring software installed 01/2024 at 27,500 miles, and out of battery jail in 06/2024. Currently at about 42,750 miles.

 

[jahorsle]

Just got the U3636 error yesterday on my 2021 EV at 65000 miles. Software update was about 10000 miles ago and the 80% limit went away as scheduled. Earliest appointment I could find around me with an EV tech is in 5 days. Bumper to bumper warranty has expired and it's $180 diagnostic fee unless it's determined to be a warranty repair. My question is if my error can be fixed with another software update will that be covered under the 8 year/100k battery warranty? Obviously if it's a new battery it would be covered, but I'll be pretty annoyed if I have to pay because their remedy software is too aggressive with identifying bad batteries. Thanks.

Per the announcement of the U3636 code TSB, the reprogram should be free of charge on all cars through 2-2026. It’s a fault involved with the original battery monitoring update. All GM fixes come with some warranty. I don’t know why your dealer is charging a diagnostic fee. Maybe they have to say it until it’s verified to be a true U3636 issue.

 

[greendave]

+1

Bought my 2020 secondhand last March with 24k miles and the 80% charge limit (all software updates applied). At 30k miles, the limit went away. Car worked fine until last week when it cr*pped out during a DCFC session (24kW ChargePoint unit). It stopped itself charging at 90%, threw the usual 'Service Vehicle Soon', 'Propulsion Reduced' errors and reset the charge limit to 30%. Got P1E00 + U362C. Car has 46k miles on it. Dealer has contacted GM to arrange for a replacement.

Ironically I traded in my happy and working 2019 w/112k miles for this 2020, thinking it would get me an extended battery warranty and some piece of mind. 2019 did ~40k miles on the factory battery and ~70k on the replacement - never threw any error codes.

I wish we could get some numbers on the failure rates on the 2020s (and the older ones too). Feels like an out-of-warranty Bolt may not be such a great deal after all...

 

[greendave]

Just saw another instance of a double failure.

My dealer confirmed they have at least 6 Bolts waiting for battery replacements right now. Granted it's one of only 2 dealers in the south bay, but that's still not an encouraging number.

 

[cwerdna]

Thanks to numerous posts in the other thread like https://www.chevybolt.org/threads/u...-months-wait-for-replacement-battery.57943/page-10?post_id=1032174#post-1032174, https://static.nhtsa.gov/odi/tsbs/2025/MC-11013832-0001.pdf came out Feb 5, 2025:

"GENERAL MOTORS
DCS7137
URGENT - DISTRIBUTE IMMEDIATELY
Date: February 5, 2025
Subject: N232421261 - Service Update
False DTC Causing Unnecessary Battery Pack Replacements (NACS Adapter)..."

"Condition Certain 2020 – 2022 model year Chevrolet Bolt EV and 2022 model year Chevrolet Bolt EUV vehicles may have a condition in which a false diagnostic trouble code (DTC), U3636 symptom 09, is triggered. This false DTC is resulting in customers experiencing a Malfunction Indicator Lamp (MIL) illuminated in the Driver Information Center (DIC), a Reduced Propulsion message, and a charging limited to 30% State of Charge. Since this is a false DTC, it can lead to unnecessary battery pack replacements.

Correction Dealers are to reprogram the Hybrid Powertrain Control Module 2 and provide the customer with a free NACS Adapter...."

 

[BlueBoltEV]

Trying to be proactive about this before our summer road trip to the Pacific Northwest, I just called my dealer, Putnam Chevy in Burlingame, CA to schedule this update N232421261 for our 2020 Premier built in 9/2020.

The service advisor that I spoke to doesn't think this applies to my Bolt for these two reasons, and so couldn't schedule me an appointment:
1. Looking up my Bolt by VIN (which they knew from my phone number as their customer), this update N232421261 does not show as pending for my VIN.
2. GM has not sent me a letter or an email telling me about it (mentioned on pages 1 and 6 of the bulletin).
He sounded sincere about actually looking it up and reading the bulletin while we were on the phone. Maybe I'll call and check again in a month. I've had applied every other software update that I've read about in this fine forum.

 

[cwerdna]

As I posted at https://www.chevybolt.org/threads/u...-months-wait-for-replacement-battery.57943/page-15?post_id=1035043#post-1035043, there's yet another update to the update (it seems) dated sometime in April 2025. It has an April 3, 2025 date on NHTSA's site.

In part, my post said:
"While digging thru the manufacturer communications section of https://www.nhtsa.gov/vehicle/2020/CHEVROLET/BOLT%2520EV/5%2520HB/FWD#manufacturerCommunications, I found this:
"April 3, 2025 MANUFACTURER COMMUNICATION NUMBER: 23-NA-157
Components: ELECTRICAL SYSTEM, FUEL/PROPULSION SYSTEM

NHTSA ID Number: 11017517
Manufacturer Communication Number: 23-NA-157

Summary
This service bulletin provides repair information to correct a customer concern of a Malfunction Indicator Lamp (MIL) illuminated in Driver Information Center (DIC), a Reduced Propulsion message, and charging limited to 30% State of Charge (SOC)...."

It pointed to this doc at https://static.nhtsa.gov/odi/tsbs/2025/MC-11017517-0001.pdf..."

Bulletin does say:
"Some customers may comment on a Malfunction Indicator Lamp (MIL) illuminated in the
Driver Information Center (DIC), a Reduced Propulsion message, and charging limited to
30% State of Charge (SOC).

Technicians may find DTC U3620, U3622, U3624, U3626, U3628, U362A, U362C,
U362E, U3630, U3632, U3634 or U3636 set current or in recent history..."

See the rest of the TSB for nuances about the BIN (Battery Identification Number) and whether it's eligible for a calibration only repair vs. needs replacement.

 

[cwerdna]

There might be yet another update to the update. Someone at

https://www.facebook.com/groups/chevyboltevowners/posts/4064917153819880/

today posted the attached that's dated June 23, 2025. Unclear if the procedure changed or software or both.

I took a peek at https://www.nhtsa.gov/vehicle/2020/CHEVROLET/BOLT%2520EV/5%2520HB/FWD#manufacturerCommunications and don't see any MCs dated that new yet. Latest is currently June 20, 2025. I wonder if it'll show up there, eventually.

 

[kent]

There might be yet another update to the update. Someone at

https://www.facebook.com/groups/chevyboltevowners/posts/4064917153819880/

today posted the attached that's dated June 23, 2025. Unclear if the procedure changed or software or both.
View attachment 73997
I took a peek at https://www.nhtsa.gov/vehicle/2020/CHEVROLET/BOLT%2520EV/5%2520HB/FWD#manufacturerCommunications and don't see any MCs dated that new yet. Latest is currently June 20, 2025. I wonder if it'll show up there, eventually.

Yeah, I went on NHTSA too and it said no updates, but I wonder where the update above emanated from?GM?
I did have a software update done on my Bolt in order to get the adapter...that's close to a year ago. Didn't have anything to do with the battery. Sounds like this update is for people getting the "reduced propulsion" warning or whatever. Please god, I don't want to go for another frickin update...

 

[cwerdna]

Yeah, I went on NHTSA too and it said no updates, but I wonder where the update above emanated from?GM?

The poster said his dealer emailed it to him and it seemed like it was after updating his car. I haven't followed his posts but he posted on June 22, 2025 about propulsion reduced error again, multiple dealerships, multiple batteries, at least 1 software update before, etc.

The screenshot of that June 23 bulletin is from a post today (June 24).

One could join that FB group at

https://www.facebook.com/groups/1521572851487669/

and look at that post and others. His initials are RR. Name of the group is Chevy Bolt EV and EUV Owners Group.

 

[MichBolt]

There might be yet another update to the update. Someone at

https://www.facebook.com/groups/chevyboltevowners/posts/4064917153819880/

today posted the attached that's dated June 23, 2025. Unclear if the procedure changed or software or both...

The bulletin says it's the same as updates after 9-26-24, so the latest software update is at least after that. But it doesn't mean there's a new software update in June 2025 - it could be a software update from 9-27-24, just with updated instructions for dealerships now.

 

[Mangled Jargon]

This just in:
P1E00 (no AC)
U3632
My car's 80% limit did not clear after the usual mileage, so Chevy wrote special code (as I was told by the dealer's techs) to override that limit. I don't have the miles driven since that software update, this just happened after work and I have to get to a meeting. But it could be 5000 miles, since I drive 20K+ annually. I have a thread in these fora about that code update.

 

[cwerdna]

This just in:
P1E00 (no AC)
U3632
My car's 80% limit did not clear after the usual mileage, so Chevy wrote special code (as I was told by the dealer's techs) to override that limit. I don't have the miles driven since that software update, this just happened after work and I have to get to a meeting. But it could be 5000 miles, since I drive 20K+ annually. I have a thread in these fora about that code update.

Indeed. There was 24-NA-035 per https://www.chevybolt.org/threads/6...eads/6400-miles-since-update-but-80-limit-is-still-in-place.57891/#post-1016121.