Bosch error 0x550350: Front light failure detected by drive unit
The drive unit has detected a problem on the front light circuit — either a failed LED or bulb, a wiring break, or the light drawing too much or too little current. As a result the front light will not switch on when commanded by the display, and on some firmware versions the bike will refuse to enter ride modes that require a working light. The motor itself still assists normally; only the lighting function is lost.
| Drive system | Bosch eBike (DiagnosticTool / eBike Flow hex code) |
| Severity | Fix at home |
| Keep riding? | Safe to keep riding |
| Typical cost | A Bosch-approved front light and plug typically run €45–€120 for the parts, with dealer labour of €40–€80 if diagnosis points to a drive unit fault. |
Likely causes
- Burnt-out LED module or bulb in the front light housing
- Damaged, pinched, or chafed cable between the light and the drive unit
- Corroded or moisture-laden connector at the headlight or motor plug
- Aftermarket light fitted without Bosch specification, drawing incorrect current
- Water ingress shorting the lamp or its plug after wet weather or washing
How to fix Bosch error 0x550350
- Switch the system off and inspect the front light lens for cracks, discolouration, or water inside the housing.
- Trace the light cable back to the drive unit and look for pinch points, chafing, or broken strands, especially near the stem and head tube.
- Unplug the light connector at both ends and check for green corrosion, bent pins, or dampness.
- Clean the contacts with electrical contact cleaner, dry everything, and reassemble; power the system on and test the light.
- If the light still does not light, replace the front light and its plug as a matched set with a Bosch-approved part and retest.
- If a known-good replacement light still does not switch on, the drive unit output stage is likely damaged — stop DIY work and hand the bike to a Bosch dealer for diagnostic-tool testing.
Warranty: A genuine LED or internal wiring fault inside the two-year Bosch warranty window is normally covered as a component defect, whereas crash damage, water ingress, and non-approved aftermarket lights are typically treated as wear or misuse and excluded.
Typical cost: A Bosch-approved front light and plug typically run €45–€120 for the parts, with dealer labour of €40–€80 if diagnosis points to a drive unit fault.
Frequently asked
Can I reset Bosch error 0x550350?
There is no user-accessible reset that clears a hard-wired light fault — the code only goes away once the drive unit sees a light drawing the correct current on the next power-on. Replacing the faulty light or its plug and then cycling the system is the only reliable way to clear it.
Is it safe to keep riding with this error?
Yes, the motor continues to assist normally and only the front light is affected, so the bike remains rideable in daylight. Riding after dark without a working front light is illegal in most countries and should be avoided until the light is repaired.
How much will the repair cost, and is it covered by warranty?
A replacement headlight and plug typically comes to €45–€120 including fitting, and within the Bosch two-year warranty period a genuine component fault is usually covered. Crash damage, water ingress, or fitting a non-approved light normally voids the warranty on that part.
Related Bosch codes
Manuals and video
- Bosch eBike Help Center: official error-code index
- Bosch eBike downloads: quick start guides and battery guide
- Bosch eBike dealer search (DiagnosticTool readout)
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.