Shimano STEPS error W222: Drive unit CAN connection fault
The drive unit has flagged an electrical abnormality at its CAN terminal, which is the data line that links the drive unit to the rest of the system. When W222 is active, motor assist is usually cut back or disabled entirely, walk assist is unavailable, and the display may stop showing speed or battery data from certain components. The bike remains rideable, but only on human power.
| Drive system | Shimano STEPS (E5000, E6100, E7000, E8000, EP6, EP801) |
| Severity | Warning |
| Keep riding? | Ride with caution |
| Typical cost | Dealer diagnostic typically runs €40 to €120, a replacement CAN cable €50 to €150, and a full drive unit replacement €400 to €900 depending on the STEPS model. |
Likely causes
- Loose, dirty, or corroded connector at the CAN port on the drive unit
- Moisture or water ingress inside the CAN port or its cable connector
- Damaged CAN wiring pinched against the frame or worn at a bend point
- An accessory or diagnostic tool left plugged into the CAN port
- Bent or pushed-in pins inside the CAN connector
- Corroded or oxidised contacts after winter storage or pressure washing
How to fix Shimano STEPS error W222
- 1. Switch the system off and remove the battery before touching any connectors.
- 2. Inspect the CAN port on the drive unit for moisture, dirt, or green corrosion; clean and dry it if found.
- 3. Unplug any device fitted to the CAN or diagnostic port and refit the original blanking cap.
- 4. Trace the CAN cable along the frame and look for chafing, pinching, or signs of rodent damage.
- 5. Refit the battery, power the bike on, and ride briefly to see whether W222 clears.
- 6. If the code returns or the bike still shows reduced assist, book the bike in with an authorised Shimano STEPS dealer for a full diagnostic.
Warranty: A genuine CAN port or internal drive unit communication fault is normally treated as a component defect and covered for two years from purchase, while water ingress from pressure washing, crash damage, and aftermarket modifications are excluded.
Typical cost: Dealer diagnostic typically runs €40 to €120, a replacement CAN cable €50 to €150, and a full drive unit replacement €400 to €900 depending on the STEPS model.
Frequently asked
Can I reset Shimano error W222?
Often yes: power off, remove the battery for around 30 seconds, disconnect anything plugged into the CAN port, then restart the system. If W222 comes back immediately, the fault is still active and needs investigation rather than another reset.
Is it safe to keep riding with W222 active?
The motor will usually drop to no assist or a very reduced mode, so you can ride home or to a workshop cautiously using your own effort. Do not ignore it, since the warning can mask a connector or wiring problem that may worsen.
Will Shimano cover this repair under warranty?
Genuine CAN communication faults on a STEPS drive unit are usually covered for two years from the date of purchase with proof of receipt. Damage caused by water ingress, crashes, or non-genuine accessories is not covered.
Related Shimano STEPS codes
Manuals and video
Official source: si.shimano.com
Not an official Shimano STEPS document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.