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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 913–936 of 1228

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U0645Lost Communication With Active Air Dam ModuleCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0645 concerns lost communication with active air dam module. Learn what this fault indicates and where to begin diagnosis.U0646Lost Communication With Motor Electronics Coolant Pump ACheck soonNetwork & Communication45–120 minutes for initial diagnosisU0646 concerns lost communication with motor electronics coolant pump a. Learn what this fault indicates and where to begin diagnosis.U0647Lost Communication With Motor Electronics Coolant Pump BCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0647 concerns lost communication with motor electronics coolant pump b. Learn what this fault indicates and where to begin diagnosis.U0648Lost Communication With Motor Electronics Coolant Pump CCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0648 concerns lost communication with motor electronics coolant pump c. Learn what this fault indicates and where to begin diagnosis.U0649Lost Communication With Coolant Pump DCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0649 concerns lost communication with coolant pump d. Learn what this fault indicates and where to begin diagnosis.U064ALost Communication With Hybrid/EV Battery Pack Current Sensor ACheck soonNetwork & Communication45–120 minutes for initial diagnosisU064A concerns lost communication with hybrid/ev battery pack current sensor a. Learn what this fault indicates and where to begin diagnosis.U064BLost Communication With Hybrid/EV Battery Pack Current Sensor BCheck soonNetwork & Communication45–120 minutes for initial diagnosisU064B concerns lost communication with hybrid/ev battery pack current sensor b. Learn what this fault indicates and where to begin diagnosis.U064CLost Communication With Hybrid/EV Battery Pack Current Sensor CCheck soonNetwork & Communication45–120 minutes for initial diagnosisU064C concerns lost communication with hybrid/ev battery pack current sensor c. Learn what this fault indicates and where to begin diagnosis.U064DLost Communication With Trailer Brake Control SwitchCheck soonNetwork & Communication45–120 minutes for initial diagnosisU064D concerns lost communication with trailer brake control switch. Learn what this fault indicates and where to begin diagnosis.U064ELost Communication With EGR Cooler Bypass Position Sensor Bank 1Check soonNetwork & Communication45–120 minutes for initial diagnosisU064E concerns lost communication with egr cooler bypass position sensor bank 1. Learn what this fault indicates and where to begin diagnosis.U064FLost Communication With Intake Manifold Runner Position Sensor Bank 1Check soonNetwork & Communication45–120 minutes for initial diagnosisU064F concerns lost communication with intake manifold runner position sensor bank 1. Learn what this fault indicates and where to begin diagnosis.U0650Lost Communication With Exhaust Pressure Control Valve A Sensor/SwitchCheck soonNetwork & Communication45–120 minutes for initial diagnosisU0650 concerns lost communication with exhaust pressure control valve a sensor/switch. Learn what this fault indicates and where to begin diagnosis.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.