GUIDE / OBD-II
清码前保存冻结帧
冻结帧反映记录故障时的部分工况。工具支持时，保存转速、负荷、水温、车速、燃油系统状态和燃油修正。快照可能只对应某个故障，并非连续记录。清码可能删除资料并重置就绪状态。驾驶时不要操作扫描仪。
更换零件之前
记录报码及冻结帧，检查蓄电池状态、相关报码和可见的线束或软管损伤。按照该车诊断流程和测试结果决定维修，避免仅凭故障码换件。
扫描记录表 →有原厂依据的故障码释义
来源与解读范围
先理解含义，再核对所引原厂页码。通用参考说明和限定车型案例的适用范围不同，采用维修指令前须确认具体应用。
- 2000 Powertrain Control/Emissions Diagnosis — Villager OBDII, Description and Operation ↗
Ford Motor Company · PDF 14, 18
2000 Mercury Villager example: stored operating conditions at fault detection, scan-tool access and single-event priority/replacement behavior. Printed pages 1-14 and 1-18. Does not establish how many frames every modern control module supports.
- On-Board Diagnostic Hand-Held Scan Tool Technology — EPA420-R-00-017, October 2000 ↗
U.S. Environmental Protection Agency
Historical emissions scan-tool report, printed page 6: Mode 2 retrieves freeze-frame information; Mode 4 resets emissions diagnostic information including freeze frame and readiness. Background for preserving data before clearing, not validation of a current scanner or every module. Text edition has no PDF page anchors.