King-Meter error 04: Throttle not returning to rest position
The display has detected that the throttle signal is outside its normal idle range when the twist grip should be released. Motor assistance driven by the throttle is cut off, walk-assist is disabled, and the speed reading still works while pedalling. The fault stays latched on the screen until the throttle voltage falls back to its rest value and the bike is power-cycled.
| Drive system | King-Meter K5242 / KM5S LCD display |
| Severity | Fix at home |
| Keep riding? | Ride with caution |
| Typical cost | A replacement throttle costs about €15-40 as a part, dealer fitting adds €30-60 in labour, and a full controller-side diagnosis runs €50-90 if the throttle end proves sound. |
Likely causes
- Throttle grip stuck open, not springing fully back to rest
- Moisture or corrosion inside the throttle connector at the handlebar or controller
- Pinched, kinked, or broken throttle cable along the bar or frame
- Worn hall sensor inside the throttle housing
- Loose three-pin throttle plug not seated against its rubber boot
How to fix King-Meter error 04
- Switch off the display and remove the battery before any checks.
- Twist the throttle fully and release it several times to dislodge grit or a sticky grip.
- Inspect the throttle cable for kinks, sharp bends, or pulled strands along the bar.
- Unplug the throttle connector and look for green corrosion or bent pins, then reseat it firmly.
- Measure the throttle output with the battery on: roughly 0.8 V idle, rising to 3.6-4.2 V at full twist. An idle reading above about 0.9 V confirms a faulty throttle.
- Fit a matching King-Meter throttle if the voltages are out of spec, then power-cycle the bike.
- Hand the bike to a dealer if the throttle, cable, and plug all check good, since the controller input then needs workshop diagnosis.
Warranty: A genuine throttle component failure inside the first two years is normally treated as a manufacturing defect and covered, while water ingress, crash damage, and worn grips are excluded.
Typical cost: A replacement throttle costs about €15-40 as a part, dealer fitting adds €30-60 in labour, and a full controller-side diagnosis runs €50-90 if the throttle end proves sound.
Frequently asked
Can I reset king-meter error 04?
Yes, by switching off the display, waiting around 30 seconds, and turning the system back on with the throttle fully released. If the code reappears at idle the throttle is not returning to its rest voltage and the underlying cause has to be fixed first.
Is it safe to keep riding with error 04?
Pedalling still works, so you can ride home cautiously without throttle or walk-assist. Avoid hills, heavy loads, or traffic situations where motor help is expected, and repair the fault before relying on the throttle again.
How much will the repair cost, and is it under warranty?
A DIY throttle swap runs €15-40 in parts and a dealer fit adds €30-60 in labour. Within two years of purchase a genuine component fault is usually covered, but water ingress or crash damage to the throttle is not.
Related King-Meter codes
Official source: King-Meter K5242 LCD manual, appendix 1 Error Code Definition
Not an official King-Meter document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.