For reference only. Always confirm part numbers and procedures for your specific vehicle.
Technical guide
Full-Vehicle Fault Codes at Service: Record Before Clearing
The BYD Qin L DM-i service schedule says to record whole-vehicle fault codes before clearing them. Why the original record matters for diagnosis.
Full-vehicle fault codes at a service: keep the original record before clearing
Scope: 2026 Qin L DM-i, China mainland; PDF p. 356; evidence-handling knowledge for technicians, no tool procedures
The order affects the diagnostic evidence
This car's maintenance schedule includes recording fault codes from every vehicle module, and notes that they are cleared after recording. A fault code is a lead for investigation, not proof that a part has failed. When owners see the list, they shouldn't decide how many parts to replace by the number of codes, and technicians should link the actual status of each code to the complaint. [1]
Keep the information rather than guessing its meaning
We suggest the job record keeps the original report, when it was taken, the vehicle version and the symptoms at the time, with the codes interpreted by someone who has the information for this model. Copying a single code into a chat window easily loses context such as history, current status and conditions. If an official definition can't be found, record it as unconfirmed; don't apply another brand's interpretation or invent a code table. [1]
A light going out doesn't close the case
No warning for a while after clearing only shows that the current display has changed; a repair still needs the actual cause and evidence from a professional re-check. If there is a safety problem, stop road tests and use, and follow service guidance. This article gives no steps for connecting a diagnostic tool, clearing codes, programming or testing control units; the original record shouldn't be overwritten just to make handover easier. [1]
Sources
[Source 1] BYD China official website: 2026 Qin L DM-i Owner's Manual (in Chinese) (public PDF on the official website)
https://www.byd.com/material/domestic-official/user-manual/dynasty/2026%E6%AC%BE%E7%A7%A6L%20DM-i%E7%94%A8%E6%88%B7%E6%89%8B%E5%86%8C20260417.pdf
Verified: 2026-10-03; page publication date not confirmed.
This article contains information-organising suggestions from the editorial team; it is not a manufacturer repair procedure.
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