Suche
U0073
System
Network (CAN Bus)
Benötigter Scanner
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Control Module Communication Bus Off

Understand U0073, common causes, and the right TOPDON scanner to diagnose it.

The CAN bus is offline — no module communication. Often wiring, termination, or a module shorting the bus.

Häufige Symptome

  • Multiple warning lights
  • No-start
  • Gauges dead
  • Many U-codes at once

Typische Ursachen

  • CAN wiring damage
  • Failed module pulling bus down
  • Corrosion in DLC or junction connectors
  • Aftermarket device on OBD port

Welchen Scanner brauchen Sie?

Full-system scanner (engine, ABS, SRS, transmission, service resets)

Nutzen Sie Live-Daten und Freeze Frame, bevor Sie Teile tauschen. ABS-, SRS- und U-Codes erfordern meist einen Vollsystem-Scanner.

Diagnose-Tipps

  • Freeze Frame erfassen, wenn der Code erstmals gesetzt wird
  • Code erst nach Behebung der Ursache löschen
  • Auf verwandte pending codes prüfen
  • Batteriespannung über 12,4 V prüfen, bevor Sie Sensoren verdächtigen

Empfohlene TOPDON Scanner

Häufig gestellte Fragen

What does U0073 mean?
U0073 indicates control module communication bus off. The CAN bus is offline — no module communication. Often wiring, termination, or a module shorting the bus.
Can I diagnose U0073 with a basic code reader?
U0073 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Which TOPDON scanner do I need for U0073?
Full-system scanner (engine, ABS, SRS, transmission, service resets) See recommended tools on this page.
Is it safe to drive with U0073?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.