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Bosch error 422: Drive unit connection problem

Bosch BES2 (Purion, Intuvia, Kiox, Nyon)Dealer neededDo not keep riding

The display cannot establish a connection to the drive unit (motor). The display may switch on but shows no speed or assist, or it keeps rebooting. This is a communication failure between display and motor, not necessarily a motor fault.

Likely causes

Loose or unlocked plug on the cable between display holder and drive unit
Corroded or wet connector at the drive unit, often after pressure washing
Cable pinched or cut where it enters the frame or passes the head tube
Dirty or bent contacts on the display holder
Drive unit electronics have failed and no longer respond

How to fix Bosch error 422

Switch off and remove the battery
Clean the display holder contacts and reseat the display
If reachable, unplug and refit the display cable at the drive unit; look for green corrosion or moisture and dry it
Check the cable route for crush damage near the stem, headset and frame entry
Refit the battery and switch on
If the code persists, a dealer must test the harness and drive unit with DiagnosticTool

Go to a dealer if: A dealer is needed when the connectors are clean and seated but the display still cannot reach the motor; the harness or drive unit then has to be tested and replaced.
Warranty: Dirty contacts, damaged cables and water ingress are treated as wear or user damage and are rarely covered; a genuine component fault within the 2-year warranty normally is.
Typical cost: A display cable is about 20-60 EUR/USD plus labour; if the drive unit itself has failed, expect 500-1000 EUR/USD out of warranty.

Still stuck? Take a photo of the display and show it to a local e-bike workshop. Bring the bike's system name (e.g. Bosch Performance Line CX) and the exact code; that saves diagnostic time and money.

Frequently asked

Can I reset Bosch error 422 myself?

You can clear it by fixing the connection (reseating or drying the plug) and restarting. If the drive unit's electronics are dead there is nothing to reset.

Can I keep riding with error 422?

No, not with assistance. The system switches the motor off for this code. The bike still works as a normal pedal bike, so you can ride home on muscle power, but the fault has to be cleared before assistance comes back.

Is error 422 covered by warranty?

Dirty contacts, damaged cables and water ingress are treated as wear or user damage and are rarely covered; a genuine component fault within the 2-year warranty normally is.

Related Bosch codes

424 · Communication error between components 500 · Internal fault in the drive unit 423 · Battery connection problem

Not an official Bosch document. Compiled from workshop experience and public service information; details can differ per system version and bike brand.