U0100
Stop drivingNetwork & modulesLost communication with ECM/PCM
Other modules can't reach the engine computer.
Common causes
- Failed engine control module
- Wiring fault
- Power/ground issue
Can I keep driving?
No. Stop driving and get it looked at. Continuing risks serious damage or a safety failure.
Who fixes U0100
This one falls under Fault code diagnosis. Verified specialists can read it live over a remote session, usually in a few minutes — you only pay if it works.
Full guide
U0100 meaning: Lost Communication With ECM/PCM A ExplainedLearn what U0100 means, common causes, symptoms on scan tools, DIY checks, and when to consult a specialist for lost ECM communication.Related codes
These explanations are from a curated DTC knowledge base. Manufacturer-specific codes may need a specialist's hands-on read.