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P20B2: Reductant Heater Coolant Control Valve Performance/Stuck Open

What Does P20B2 Mean?

P20B2 is a diagnostic trouble code indicating: Reductant Heater Coolant Control Valve Performance/Stuck Open. This code relates to the powertrain 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.