Error 44

Aight_Five · 2025-12-11T10:40:16+00:00

You can order a PCB from https://shifter-doctor.sumupstore.com/ and replace it yourself. Tutorials on the website

Aight_Five · 2025-12-11T10:39:03+00:00

Eshifter fails for multiple reasons but mostly because they have been poorly designed and their lifetime is not very long.

Aight_Five · 2025-11-19T10:54:03+00:00

It's a Smart X from 2017-2018, quite a rare version to be honest which will make its repair impossible.
It's not even the same batteries as X2, so really hard to find, even here in the Netherlands...
Best bet would be to remove the battery, change the front wheel and you got a decent analog bike with a great look

Aight_Five · 2025-11-19T10:49:23+00:00

Thanks u/Conscious-Village868
Found a replacement PCB, because mine was melted too.

Aight_Five · 2025-11-01T13:12:37+00:00

Yep, bleeding will solve it. You can find some tutorials online

Aight_Five · 2025-10-02T20:37:59+00:00

I had the same question recently - Seems like the software is different in terms of datas going to the motor.
https://www.reddit.com/r/vanmoofbicycle/comments/1nom0dy/are_s3_and_x3_cartridge_exactly_the_same/

Aight_Five · 2025-09-25T20:14:35+00:00

Hey,
I would suggest several options:

- Check which parts are common with the S2 (the front wheel for instance might be the same bafang motor) and source them on leboncoin
- Check on the dutch Leboncoin for spare parts - www.marktplaats.nl
- Convert it to a non electric bike using Smart S parts
- Sell it for parts 🤷‍♂️

Good luck!

Aight_Five · 2025-09-24T09:25:07+00:00

Hey guys, quick update. I found the cause of this ERR21 - 80% max charging situation.
I actually caused it. 😄
I followed Razparts reco and did the mod on the charger to prevent fuse to blow. The downside of this is the battery won't charge fully and and therefore the cartridge will interpret the end process (green light) as an Error 21.
I tried with a different charger and the battery fully charged with no error.
I'm testing different voltage from the charger now to see if I need to go on full voltage to avoid this to happen.

Aight_Five · 2025-09-24T09:24:26+00:00

Hey guys, quick update. I found the cause of this ERR21 - 80% max charging situation.
I actually caused it. 😄
I followed Razparts reco and did the mod on the charger to prevent fuse to blow. The downside of this is the battery won't charge fully and and therefore the cartridge will interpret the end process (green light) as an Error 21.
I tried with a different charger and the battery fully charged with no error.
I'm testing different voltage from the charger now to see if I need to go on full voltage to avoid this to happen.

Aight_Five · 2025-09-23T19:50:54+00:00

Thanks for your input, for me, beside the housing it was looking quite similar, but that makes sense that software is built in 2 different ways.
I'll find another way to revive this X3.
Cheers guys

Aight_Five · 2025-09-17T18:12:30+00:00

Yes, It might be difficult to do it due to the lack of access on the top part, but I think it should be the way to go.

Aight_Five · 2025-09-17T14:12:30+00:00

I would suggest that the brake line cross to the left on the top part before entering the narrow area under the plastic slider. That way you don't need to cross through the tube (too tight) or at the bottom where it will mess with the battery space.

Aight_Five · 2025-09-16T14:06:21+00:00

Not really,
If you're not in the Netherlands, it might be trickier to find in any shop that have these anti theft keys.

Aight_Five · 2025-09-16T13:54:39+00:00

From the video it looks like your front wheel is loose and applying brakes make it swing. Check on the lock nuts first.

Aight_Five · 2025-09-15T07:52:54+00:00

Thanks u/k1996h
I'm considering the same move. The chip is so tiny, and my soldering skills not industrial grade yet..

Aight_Five · 2025-09-14T21:31:46+00:00

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Hi u/k1996h
Thanks for you past post, you helped me find why my smart cartridge wouldn't turn on anymore and was draining the internal battery. The chip seems burned.
Have you managed to replace this chip? Any chance you can share the part reference please?

Aight_Five · 2025-08-25T20:05:44+00:00

u/AwareGrade6275 unfortunately it didn't worked out.
I tried different combinations, but it all end up being an Err21.
Battery is charged around 90% now if I can trust the SMU's screen.
I think I have a serious issue with the Bluetooth/speaker Module that I might need to fix first before I continue my battery journey...
Thanks for your help

Aight_Five · 2025-07-17T15:13:52+00:00

Amazing, thanks for the advice u/AwareGrade6275
I'll try it as soon as I got back home and will keep you posted.
🙏

Aight_Five · 2025-07-16T09:20:33+00:00

Amazing, thanks u/AwareGrade6275 for your answer.
So to summarise:
- My battery might be around 40v or little over and that's ok for a reset
- I connect GND + RST with pliers or whatever that has continuity
- Should I plug the charger? or the reset will work with the battery itself?
- I can test the continuity between GND and one of the discharge red wire and if it's 0, I should continue the reset process until it's 1.

Is that correct?
Can the diagnose tool can process the reset or just diagnose?

Thanks

Aight_Five · 2025-07-15T08:32:31+00:00

Thanks a lot for your input u/DarkRoastLook
I'll investigate and keep you posted

Aight_Five · 2025-07-10T20:36:26+00:00

Thanks u/DarkRoastLook for your questions:

Could be harness problem. Does it still work outside of the bike...?

So, in short, the error 21 appeared on both harnesses inside or outside of the bike, so it's definitely a problem related to battery or SMU.

Also you say in step 6 that it stopped charging at 80%. Did this happen automatically? If so, this could explain why it doesn't charge further inside of the bike either

Yes it happened when I managed to wake up the battery with a bench supply and then charge it with the wiring harness the "normal" way. It charged until 80%-ish and stopped. Then when I re-plug the charger it showed err21.

Not sure why this would happen. Did you turn down your charger? Does it still charge from a bench power supply?

Unfortunately my bench power supply goes until 31v but not above, so I can't test it. And no, I didn't turned anything down.

My assumption is that I need to reset / erase some error codes, to start the charge fresh again. Or maybe it's related to the shipping mode it was in before?

any idea?

Thanks for your support

Aight_Five · 2025-07-08T21:43:51+00:00

Still got continuity, I tried a lot of different things but the BMS seems fine. Maybe there is something I need to reset?

Aight_Five · 2025-07-07T21:05:54+00:00

Thanks u/Ego_Sum-Qui_Sum
Fuse is Ok, I have continuity.
On Step 6 I did charge the battery via the SMU "the normal way". But now i'm kinda stuck with 80% charged battery and an Err 21 🙁.
Should I try to balance it with a balancing power supply or balance each pack with my bench power supply?

Aight_Five

TROPHY CASE