Error codes differ by brand, so users cannot self-diagnose and must consult the manual or dealer.
When a mid-drive system reports a fault, the screen often shows only a short code such as "E03" or "500". These codes follow no industry standard, and their meaning differs completely between brands, so the user cannot judge the nature of the fault.
Further diagnosis needs a dedicated handheld device or brand app, and reading the full sub-codes and history log often requires dealer account authorization. Ordinary users and third-party workshops are locked out of the information.
This opacity creates two problems. Misdiagnosis leads to unnecessary returns, and a small fault that cannot be located grows into a major repair. For B2B channels, this directly raises after-sales labor and logistics cost.
QERYU engineering answers with "transparent diagnosis". Fault codes come with a public, readable mapping table. The controller log can be exported, and we provide a standard troubleshooting flow for dealers. We let the problem be located at the store level, which reduces misdiagnosis and back-and-forth shipping.