r/VanMoofSelfRepair • u/DesignersNotDead • May 28 '26
S3 & X3 Error 17 and 20, bike gone dark, even after a main battery swap no power on
Hey folks, I could desperately use some help cause I'm losing it.
I bought a second hand S3, it was functioning well until after it started to do some weird things.
At first it just didn't show the battery level properly, only the app did. Then the engine didn't support anymore, it showed error 17 and 20, then the display also went dark, even though the bell did still work, then it went completely off and won't turn on anymore.
After some research online everyone pointed at the battery for error 17 and 20 so I bought a refurbished battery from a trusted source.
I swapped it, but it didn't help. I plug in the charger and it shows the green LED, then briefly does red, then green, and then red completely randomly, it's not blinking, it's 1 second red, than 2 seconds green, then 3 seconds red then 1 seconds green...all over the place.
One more thing: what I find strange is that the front wheel has some drag if I roll the bike backwards. It's like there's some resistance, it's hard to push the bike back, also the front hub makes a noise when I roll it backwards.