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U0074: Control Module Communication Bus B Off

What Does U0074 Mean?

U0074 is a diagnostic trouble code indicating: Control Module Communication Bus B Off. This code relates to the network communication system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

What To Do Next

  1. 1
    Find your vehicle above

    Click your make and model for real owner reports and common causes specific to your vehicle.

  2. 2
    Check for recalls

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.

  3. 3
    Get a professional diagnosis

    A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

Related Codes

U0069 Vehicle Communication Bus E (-) Open U0070 Vehicle Communication Bus E (-) Low U0071 Vehicle Communication Bus E (-) High U0072 Vehicle Communication Bus E (-) shorted to Bus E (+) U0073 Control Module Communication Bus A Off U0075 Control Module Communication Bus C Off U0076 Control Module Communication Bus D Off U0077 Control Module Communication Bus E Off