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U0691: Lost Communication With Exhaust Pressure Sensor A

What Does U0691 Mean?

U0691 is a diagnostic trouble code indicating: Lost Communication With Exhaust Pressure Sensor A. This code relates to the vehicle systems 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

U0686 Lost Communication With Catalyst Temperature Bank 2 Sensor 1 U0687 Lost Communication With Catalyst Temperature Bank 2 Sensor 2 U0688 Lost Communication With Throttle Position Sensor/Switch G U0689 Lost Communication With Turbocharger/Supercharger B Temperature Sensor U0690 Lost Communication With EGR Temperature Sensor D U0692 Lost Communication With Exhaust Pressure Sensor B U0693 Lost Communication With Humidity Sensor U0694 Lost Communication With Hybrid/EV Battery Pack Coolant Pump A