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9,253 diagnostic guides

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Find codes by symptomChoose what you notice to search matching code guides.

Rough idle or shakingVibration while stopped Hard to startLong cranking or no-start Engine stallsCuts out at idle or on the road Hesitates or loses powerSlow response when accelerating Battery light is onCharging system warning Harsh gear changesDelayed or rough shifting

A symptom can have several causes. Treat matching codes as clues and follow the diagnostic checks in each guide.

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Engine1049 Emissions515 Fuel1016 Sensors & Electronics2110 Transmission866 Electrical & Charging1797 Body & Restraints193 Chassis & Brakes479 Network & Communication1228

FiltersSeverity · family

Severity

All severities9253 Low priority305 Check soon8256 Urgent621

Code family

All families9253 P · Powertrain7353 B · Body193 C · Chassis479 U · Network1228

Vehicle coverage

These are generic OBD2 definitions. Exact make, model, engine, and year compatibility will appear after vehicle-fitment data is added.

Diagnostic codes

Showing 7825–7848 of 8256

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U0651Lost Communication With EGR Sensor ACheck soonNetwork & Communication45–120 minutes for initial diagnosisU0651 concerns lost communication with egr sensor a. Learn what this fault indicates and where to begin diagnosis.U0652Lost Communication With EGR Sensor BCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0652 concerns lost communication with egr sensor b. Learn what this fault indicates and where to begin diagnosis.U0653Lost Communication With EGR Sensor CCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0653 concerns lost communication with egr sensor c. Learn what this fault indicates and where to begin diagnosis.U0654Lost Communication With Diesel Intake Air Flow A Position SensorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0654 concerns lost communication with diesel intake air flow a position sensor. Learn what this fault indicates and where to begin diagnosis.U0655Lost Communication With Diesel Intake Air Flow B Position SensorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0655 concerns lost communication with diesel intake air flow b position sensor. Learn what this fault indicates and where to begin diagnosis.U0656Lost Communication With Turbocharger/Supercharger Boost Control A Position SensorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0656 concerns lost communication with turbocharger/supercharger boost control a position sensor. Learn what this fault indicates and where to begin diagnosis.U0657Lost Communication With Turbocharger/Supercharger Bypass Valve A Position SensorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0657 concerns lost communication with turbocharger/supercharger bypass valve a position sensor. Learn what this fault indicates and where to begin diagnosis.U0658Lost Communication With Windshield Temperature SensorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0658 concerns lost communication with windshield temperature sensor. Learn what this fault indicates and where to begin diagnosis.U0659Lost Communication With Left Front Temperature ActuatorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0659 concerns lost communication with left front temperature actuator. Learn what this fault indicates and where to begin diagnosis.U065ALost Communication With Right Front Temperature ActuatorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU065A concerns lost communication with right front temperature actuator. Learn what this fault indicates and where to begin diagnosis.U065BLost Communication With Left Front Mode ActuatorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU065B concerns lost communication with left front mode actuator. Learn what this fault indicates and where to begin diagnosis.U065CLost Communication With Right Front Mode ActuatorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU065C concerns lost communication with right front mode actuator. Learn what this fault indicates and where to begin diagnosis.U065DLost Communication With Air Intake ActuatorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU065D concerns lost communication with air intake actuator. Learn what this fault indicates and where to begin diagnosis.U065ELost Communication With Ram Air ActuatorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU065E concerns lost communication with ram air actuator. Learn what this fault indicates and where to begin diagnosis.U065FLost Communication With Left Rear Temperature Actuator ACheck soonNetwork & Communication45–120 minutes for initial diagnosisU065F concerns lost communication with left rear temperature actuator a. Learn what this fault indicates and where to begin diagnosis.U0660Lost Communication With Left Rear Temperature Actuator BCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0660 concerns lost communication with left rear temperature actuator b. Learn what this fault indicates and where to begin diagnosis.U0661Lost Communication With Right Rear Temperature Actuator ACheck soonNetwork & Communication45–120 minutes for initial diagnosisU0661 concerns lost communication with right rear temperature actuator a. Learn what this fault indicates and where to begin diagnosis.U0662Lost Communication With Right Rear Temperature Actuator BCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0662 concerns lost communication with right rear temperature actuator b. Learn what this fault indicates and where to begin diagnosis.U0663Lost Communication With Rear Mode ActuatorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0663 concerns lost communication with rear mode actuator. Learn what this fault indicates and where to begin diagnosis.U0664Lost Communication With Rear HVAC Air Cutoff ActuatorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0664 concerns lost communication with rear hvac air cutoff actuator. Learn what this fault indicates and where to begin diagnosis.U0665Lost Communication With Fuel Rail Pressure Sensor Bank 2Check soonNetwork & Communication45–120 minutes for initial diagnosisU0665 concerns lost communication with fuel rail pressure sensor bank 2. Learn what this fault indicates and where to begin diagnosis.U0666Lost Communication With Reductant Pressure SensorCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0666 concerns lost communication with reductant pressure sensor. Learn what this fault indicates and where to begin diagnosis.U0667Lost Communication With Engine Oil Temperature Sensor ACheck soonNetwork & Communication45–120 minutes for initial diagnosisU0667 concerns lost communication with engine oil temperature sensor a. Learn what this fault indicates and where to begin diagnosis.U0668Lost Communication With Engine Oil Level Sensor CircuitCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0668 concerns lost communication with engine oil level sensor circuit. Learn what this fault indicates and where to begin diagnosis.