本页暂无Chinese版本，以下为英文原文。 查看英文版 →
U0401 U0xxx · 网络通信（U） 中严重度
Invalid Data Received from ECM / PCM
A module received data from the engine ECU that it considers invalid — often a software version or coding mismatch rather than a wiring fault.
严重程度说明： 中——已影响行驶或排放，请本周内安排检修
你会注意到的故障现象
- Warning lamps
- Transmission or stability functions limited
- No obvious single-module fault
常见原因
按可能性从高到低排列——从最上面开始查。
- 1 Software version mismatch between modules
- 2 Incorrect variant coding
- 3 Corrupted data on the bus
- 4 Engine ECU internal fault
如何排查
先做花钱最少、侵入最小的检查——大多数这类码不是零件问题。
- ✓ Read software versions across modules and compare with the manufacturer's compatible list.
- ✓ Check variant coding in both the sending and receiving modules.
- ✓ Look for outstanding software updates.
- ✓ Verify bus integrity only after ruling out software.
维修方案
- Update or re-flash module software
- Correct the variant coding
- Repair bus integrity if genuinely corrupted
U0401 —— 常见问题
Is the engine ECU faulty? +
Unlikely. Version and coding mismatches cause most of these.
Can a software update really fix it? +
Yes — this is one of the few codes where an update is the primary repair, not a workaround.