Home › Bosch › Error 0x550357

Bosch error 0x550357: Front light short circuit fault

Bosch eBike (DiagnosticTool / eBike Flow hex code)Fix at homeSafe to keep riding

The system has detected a short circuit on the front light circuit. The front light will typically fail to illuminate, and the drive system flags the fault on the display. Motor assist itself is not disabled by this code, which is why the bike can still be ridden, but the lighting circuit needs attention before the bike is used in low light.

Drive system	Bosch eBike (DiagnosticTool / eBike Flow hex code)
Severity	Fix at home
Keep riding?	Safe to keep riding
Typical cost	Expect roughly EUR 15-40 for a replacement OEM front light and EUR 30-80 for a harness repair at an independent workshop, rising to EUR 150-300 at a dealer if the controller needs to come out under warranty.

Likely causes

Damaged or pinched cable between the controller and the front light, often near the head tube or stem
Water or moisture inside the front light connector causing a short to ground
A failed LED module or bulb that has shorted internally
Corroded or bent pins in the front light plug
Aftermarket light fitted or spliced into the original wiring without a proper connector
Cable chafe where the harness passes through the head tube grommet

How to fix Bosch error 0x550357

Switch off the system and remove the battery before any work on the lighting circuit.
Visually trace the front light cable from the controller exit point to the lamp, looking for cuts, kinks, crushed sections, or melted insulation.
Unplug the front light at the lamp end and at the controller if the connector is accessible. Inspect both sides for green corrosion, bent pins, and moisture; dry and clean with contact cleaner if needed.
Leave the light unplugged, refit the battery, and switch the system on. If the code clears, the lamp itself or its connector is the fault.
Swap in a known-good Bosch front light of the correct type to confirm whether the original lamp is shorted. Replace the lamp if the swap clears the fault.
Repair or replace any damaged section of cable using the original connector, not solder-and-tape splices. Refit and test before riding at night.
If the code remains with the light fully disconnected, the harness or controller output is at fault; stop DIY work and book the bike in with a Bosch dealer for diagnostic and warranty check.

Go to a dealer if: Take the bike to a Bosch dealer if the code stays active with the front light fully unplugged, because the harness or controller output then needs dealer-level diagnostics and possible warranty replacement.
Warranty: A genuine short circuit inside the Bosch front light, harness, or controller is normally treated as a component fault and covered within the two-year Bosch eBike warranty, whereas water ingress, crash damage, and DIY wiring modifications are excluded.
Typical cost: Expect roughly EUR 15-40 for a replacement OEM front light and EUR 30-80 for a harness repair at an independent workshop, rising to EUR 150-300 at a dealer if the controller needs to come out under 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 0x550357?

The code will not clear while the short circuit is still present on the lighting circuit. Disconnect the front light, fix the wiring or lamp, then power the system down and back up to see if the code clears. If it returns with the light unplugged, a Bosch dealer diagnostic is required.

Is it safe to keep riding with this fault?

Riding is possible because the fault only affects the front light circuit and does not cut motor assist. Fix it promptly though, because riding without a working front light at night or in poor visibility is illegal in most countries and reduces your conspicuity.

How much will the repair cost and is it under warranty?

A lamp or connector fix at an independent workshop typically runs EUR 15-40, with a harness repair around EUR 30-80. A genuine component fault on a Bosch light, cable, or controller inside the two-year warranty period is usually covered, but crash damage and water ingress are not.

Related Bosch codes

0x503001 · Speed sensor signal missing or invalid 0x510001 · Internal sensor error stalling motor assist 0x511001 · Acceleration sensor failure in the drive unit 0x520001 · ABS component not recognised by drive unit

Manuals and video

Official source: www.ridewill.com

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