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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

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All severities9253 Low priority305 Check soon8256 Urgent621

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

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

Diagnostic codes

Showing 1321–1344 of 1939

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P2546Torque Management Request Input Signal A LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2546 relates to torque management request input signal a low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2547Torque Management Request Input Signal A HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2547 relates to torque management request input signal a high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2548Torque Management Request Input Signal BCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2548 relates to torque management request input signal b. Check the fault conditions and vehicle-specific procedure before replacing parts.P2549Torque Management Request Input Signal B Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2549 relates to torque management request input signal b range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P254APTO Speed Selector Sensor/Switch 1 Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP254A relates to pto speed selector sensor/switch 1 circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P254BPTO Speed Selector Sensor/Switch 1 Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP254B relates to pto speed selector sensor/switch 1 range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P254CPTO Speed Selector Sensor/Switch 1 Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP254C relates to pto speed selector sensor/switch 1 circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P254DPTO Speed Selector Sensor/Switch 1 Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP254D relates to pto speed selector sensor/switch 1 circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P254EPTO Speed Selector Sensor/Switch 1 Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP254E relates to pto speed selector sensor/switch 1 circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P254FEngine Hood Switch CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP254F relates to engine hood switch circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2550Torque Management Request Input Signal B LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2550 relates to torque management request input signal b low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2551Torque Management Request Input Signal B HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2551 relates to torque management request input signal b high. Check the fault conditions and vehicle-specific procedure before replacing parts.P255APTO Speed Selector Sensor/Switch 2 Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP255A relates to pto speed selector sensor/switch 2 circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P255BPTO Speed Selector Sensor/Switch 2 Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP255B relates to pto speed selector sensor/switch 2 range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P255CPTO Speed Selector Sensor/Switch 2 Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP255C relates to pto speed selector sensor/switch 2 circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P255DPTO Speed Selector Sensor/Switch 2 Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP255D relates to pto speed selector sensor/switch 2 circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P255EPTO Speed Selector Sensor/Switch 2 Circuit Intermittent/ErraticCheck soonSensors & Electronics30–120 minutes for initial diagnosisP255E relates to pto speed selector sensor/switch 2 circuit intermittent/erratic. Check the fault conditions and vehicle-specific procedure before replacing parts.P2562Turbocharger Boost Control Position Sensor A CircuitCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2562 relates to turbocharger boost control position sensor a circuit. Check the fault conditions and vehicle-specific procedure before replacing parts.P2563Turbocharger Boost Control Position Sensor A Circuit Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2563 relates to turbocharger boost control position sensor a circuit range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.P2564Turbocharger Boost Control Position Sensor A Circuit LowCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2564 relates to turbocharger boost control position sensor a circuit low. Check the fault conditions and vehicle-specific procedure before replacing parts.P2565Turbocharger Boost Control Position Sensor A Circuit HighCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2565 relates to turbocharger boost control position sensor a circuit high. Check the fault conditions and vehicle-specific procedure before replacing parts.P2566Turbocharger Boost Control Position Sensor A Circuit IntermittentCheck soonSensors & Electronics30–120 minutes for initial diagnosisP2566 relates to turbocharger boost control position sensor a circuit intermittent. Check the fault conditions and vehicle-specific procedure before replacing parts.P256AEngine Idle Speed Selector Sensor/Switch Circuit/OpenCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256A relates to engine idle speed selector sensor/switch circuit/open. Check the fault conditions and vehicle-specific procedure before replacing parts.P256BEngine Idle Speed Selector Sensor/Switch Range/PerformanceCheck soonSensors & Electronics30–120 minutes for initial diagnosisP256B relates to engine idle speed selector sensor/switch range/performance. Check the fault conditions and vehicle-specific procedure before replacing parts.