OBD-II PID Decoder (Mode 01)
Decode Mode 01 41 <PID> <data bytes> responses into RPM, speed, coolant temperature, MAF, voltage and other common OBD-II values.
Sample input is pre-filled and editable. Everything runs locally in your browser — nothing is uploaded.
Response: 41 <PID> <PID-specific data bytes>. CAN (ISO 15765-4) pads frames to 8 bytes; padding is ignored here.
FAQ
RPM = (A × 256 + B) / 4. For 41 0C 1A F8 the result is 1726 rpm.
SAE J1979 defines the data length per PID (1, 2 or 4 bytes). CAN padding is ignored; short input raises an error instead of being zero-filled.
How to use
The article body below is currently available in full only in Chinese; the interface, titles, descriptions and FAQ follow your selected language.
- 选择 PID（默认
0x0C转速）。 - 输入响应中的数据字节（不含
41与 PID），结果区显示物理值、公式、该 PID 的有效字节数与有效响应帧；多填的字节会被当作 CAN 填充忽略。
常用 PID 对照
| PID | 参数 | 公式 | 单位 | 有效字节 |
|---|---|---|---|---|
| 0x05 | 冷却液温度 | A − 40 | °C | 1 |
| 0x0C | 发动机转速 | (A·256 + B)/4 | rpm | 2 |
| 0x0D | 车速 | A | km/h | 1 |
| 0x10 | 空气流量 | (A·256 + B)/100 | g/s | 2 |
| 0x2F | 燃油液位 | A·100/255 | % | 1 |
| 0x42 | 控制模块电压 | (A·256 + B)/1000 | V | 2 |
工具内置 10 个常用 PID，均为 1 或 2 字节；完整列表与逐 PID 长度见 SAE J1979 / ISO 15031-5。
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