King-Meter error 30: Display lost link to controller
The display and the motor controller have stopped exchanging data on the signal cable. Pedal assist and throttle cut out, walk assist is disabled, and the speed reading either freezes or drops to zero. The bike can still be rolled by hand and pedalled unpowered, but none of the electric functions respond until the link is restored.
| Drive system | King-Meter SW-LCD / SW900 display |
| Severity | Fix at home |
| Keep riding? | Do not keep riding |
| Typical cost | A replacement cable or connector service typically runs €15 to €60 in parts, and a dealer diagnosis leading to a replacement SW-LCD display or controller usually lands between €90 and €280 depending on the generation. |
Likely causes
- Display cable unplugged, loose, or not fully clicked home at the handlebar or controller end - the most common cause after any wheel or bar work
- Bent, pushed-out, or green-corroded pins inside either connector, often after a wet ride or a pressure wash
- Cable chafed, pinched, or fractured where it exits the display mount or passes the head tube and stem
- Moisture or a bad ground at the controller plug following rain, washing, or a flooded cable channel
- Failed display board or controller board, only confirmed once the wiring has been ruled out
- Recent component swap or firmware mismatch where the display and controller are no longer paired correctly
How to fix King-Meter error 30
- Switch the system off and remove the battery or key before touching any connector.
- Unplug the display cable at both ends - handlebar side and controller side - and inspect the pins for bent, recessed, or green-corroded contacts.
- Clean any damp or oxidised pins with electrical contact cleaner, let them dry, and refit both connectors until the locking tab fully engages; do not use WD-40 inside electrical plugs.
- Trace the full length of the cable from display to controller, looking for chafe, a tight bend at the head tube, or pinched sections against the stem or bar.
- Reconnect the battery, power the bike on, and check whether error 30 clears and assist returns; repeat the test from cold after a full power cycle.
- If a spare known-good cable is available, swap it in to confirm whether the original harness is the fault before condemning the display or controller.
- If the code remains after all cable and connector checks, the display or controller needs dealer-level bench diagnosis.
Warranty: A genuine display or controller board failure inside the two-year component warranty is normally covered, while corrosion from water ingress, crash damage, and abuse of the cable or connectors are treated as owner damage and excluded.
Typical cost: A replacement cable or connector service typically runs €15 to €60 in parts, and a dealer diagnosis leading to a replacement SW-LCD display or controller usually lands between €90 and €280 depending on the generation.
Frequently asked
Can I reset king-meter error 30?
Powering the system off and on will clear the warning only if the underlying cable or connector has been fixed first. Cycling the ignition on its own will not repair a loose plug, corroded pin, or broken wire, and the code will reappear the moment the bike is powered up.
Is it safe to keep riding with king-meter error 30 showing?
No. With the code active the motor and throttle are switched off, so the bike becomes heavy to pedal and the speedometer may show zero or freeze. Continue only by pedalling unpowered to get home, and resolve the fault before the next ride.
How much will fixing king-meter error 30 cost and is it under warranty?
A repaired or replaced cable and connector typically costs €15 to €60 out of warranty, while a replacement display or controller can reach €280 fitted. If the failure is a true component defect inside the two-year warranty period and there is no evidence of water or crash damage, the part is normally covered by the manufacturer.
Related King-Meter codes
Official source: King-Meter SW-LCD user guide, section 6.9 Error Code Display
Not an official King-Meter document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.