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U0421: Invalid Data Received From Suspension Control Module A

What Does U0421 Mean?

U0421 is a diagnostic trouble code indicating: Invalid Data Received From Suspension Control Module A. 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

U0416 Invalid Data Received From Vehicle Dynamics Control Module U0417 Invalid Data Received From Park Brake Control Module U0418 Invalid Data Received From Brake System Control Module A U0419 Invalid Data Received From Steering Effort Control Module U0420 Invalid Data Received From Power Steering Control Module A U0422 Invalid Data Received From Body Control Module U0423 Invalid Data Received From Instrument Panel Cluster Control Module U0424 Invalid Data Received From HVAC Control Module