Controller failure
Ride-stoppingThe bike's brain is failing: burning smell, total dead bike with a good battery, or erratic surging assist.
Typical repair cost: $120-$350 including parts and labor. You get an estimate before any work starts.
Likely causes
- Heat stress from sustained loads
- Water intrusion
- Blown MOSFETs
- Connector corrosion
- Overloading from aftermarket modifications
How it gets fixed
- Controller replacement
- Wiring harness repair
- Waterproofing of connections
Try this first
A controller that smells burnt or a bike that is fully dead with a confirmed-good battery points here. There is no DIY fix for a blown controller, but confirm the diagnosis before buying parts, since dead-bike symptoms are more often a fuse or connector. Controllers must match your bike's voltage and plug standard; a tech will spec the right unit.