Class 2 Communication Malfunction
A general communication malfunction on the Class 2 serial data bus.
Informational only. Consult a qualified mechanic.
- Wiring short/open on data bus
- Faulty module
- Connector corrosion
Diagnose the data bus for shorts or opens. Identify the offending module.
What does U1000 mean?
The U1000 OBD-II diagnostic trouble code (DTC) indicates: class 2 communication malfunction. This is a high-severity network code that your vehicle's onboard diagnostics system triggers when a general communication malfunction on the class 2 serial data bus. If your check engine light is on with this code, the vehicle is generally safe to drive, but you should have it inspected soon.
Use Your Service Book to log this diagnostic trouble code to your vehicle's service history, track repairs, and get maintenance reminders — all for free.
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