U0077

Control Module Communication Bus E Off

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$6–56 (est.)

Symptoms

Unstable engine operation
Check Engine Light Is On
No communication with diagnostic scanner
Incorrect operation of other vehicle systems

Causes

CAN bus wire break
Short circuit in CAN circuit
Faulty electronic control unit E
Damage to connectors or corrosion of contacts

How to Fix

Check the integrity of the CAN bus wires
Check connectors and contacts for damage
Diagnose electronic control unit E
Replace damaged wires or connectors

Related codes

U0078 U0100 U0101