Computer Codes
427 OBD-II diagnostic trouble codes in this category.
Showing page 3 of 5 (427 codes total)
| Code | Description | Subsystem | Severity |
|---|---|---|---|
| P21E7 | Cylinder 6 Injector B Circuit High | Powertrain Control | Medium |
| P21E8 | Cylinder 7 Injector B Circuit Low | Powertrain Control | Medium |
| P21E9 | Cylinder 7 Injector B Circuit High | Powertrain Control | Medium |
| P23E3 | EGR C Control Circuit Low | Powertrain Control | Medium |
| P23E4 | EGR C Control Circuit High | Powertrain Control | Medium |
| P23E5 | EGR C Control Stuck Open | Powertrain Control | Medium |
| P23E6 | EGR C Control Stuck Closed | Powertrain Control | Medium |
| P23E7 | EGR C Flow Insufficient Detected | Powertrain Control | Medium |
| P23E8 | EGR C Flow Excessive Detected | Powertrain Control | Medium |
| P23E9 | Camshaft A Position Signal Output Circuit/Open Bank 2 | Powertrain Control | Medium |
| P24E3 | NH3 Sensor Circuit Low | Powertrain Control | Medium |
| P24E4 | NH3 Sensor Circuit High | Powertrain Control | Medium |
| P24E5 | NH3 Sensor Circuit Intermittent/Erratic | Powertrain Control | Medium |
| P24E6 | NH3 Sensor Heater Circuit/Open | Powertrain Control | Medium |
| P24E7 | NH3 Sensor Heater Circuit Low | Powertrain Control | Medium |
| P24E8 | NH3 Sensor Heater Circuit High | Powertrain Control | Medium |
| P24E9 | NH3 Sensor Heater Circuit Performance | Powertrain Control | Medium |
| P2500 | Generator Lamp/L Terminal Circuit Low | Charging System | High |
| P2501 | Generator Lamp/L Terminal Circuit High | Charging System | Medium |
| P2502 | Charging System Voltage Low | Charging System | High |
| P2503 | Charging System Voltage High | Charging System | High |
| P2504 | Charging System Output Current Low | Charging System | High |
| P2505 | ECM/PCM Power Input Signal | ECM/PCM | Medium |
| P2506 | ECM/PCM Power Input Signal Range/Performance | ECM/PCM | Medium |
| P2507 | ECM/PCM Power Input Signal Low | ECM/PCM | Medium |
| P2508 | ECM/PCM Power Input Signal High | ECM/PCM | Medium |
| P2509 | ECM/PCM Power Input Signal Intermittent | ECM Power Supply | High |
| P2510 | ECM/PCM Power Relay Sense Circuit Range/Performance | ECM/PCM | Medium |
| P2511 | ECM/PCM Power Relay Sense Circuit Intermittent | ECM/PCM | Medium |
| P2512 | Event Data Recorder Request Circuit/ Open | ECM/PCM | Medium |
| P2513 | Event Data Recorder Request Circuit Low | ECM/PCM | Medium |
| P2514 | Event Data Recorder Request Circuit High | ECM/PCM | Medium |
| P2515 | A/C Refrigerant Pressure Sensor B Circuit | ECM/PCM | Medium |
| P2516 | A/C Refrigerant Pressure Sensor B Circuit Range/Performance | ECM/PCM | Medium |
| P2517 | A/C Refrigerant Pressure Sensor B Circuit Low | ECM/PCM | Medium |
| P2518 | A/C Refrigerant Pressure Sensor B Circuit High | ECM/PCM | Medium |
| P2519 | A/C Request A Circuit | ECM/PCM | Medium |
| P2520 | A/C Request A Circuit Low | ECM/PCM | Medium |
| P2521 | A/C Request A Circuit High | ECM/PCM | Medium |
| P2522 | A/C Request B Circuit | ECM/PCM | Medium |
| P2523 | A/C Request B Circuit Low | ECM/PCM | Medium |
| P2524 | A/C Request B Circuit High | ECM/PCM | Medium |
| P2525 | Vacuum Reservoir Pressure Sensor Circuit | ECM/PCM | Medium |
| P2526 | Vacuum Reservoir Pressure Sensor Circuit Range/Performance | ECM/PCM | Medium |
| P2527 | Vacuum Reservoir Pressure Sensor Circuit Low | ECM/PCM | Medium |
| P2528 | Vacuum Reservoir Pressure Sensor Circuit High | ECM/PCM | Medium |
| P2529 | Vacuum Reservoir Pressure Sensor Circuit Intermittent | ECM/PCM | Medium |
| P2530 | Ignition Switch Run Position Circuit | ECM/PCM | Medium |
| P2531 | Ignition Switch Run Position Circuit Low | ECM/PCM | Medium |
| P2532 | Ignition Switch Run Position Circuit High | ECM/PCM | Medium |
| P2533 | Ignition Switch On/Start Position Circuit | ECM/PCM | Medium |
| P2534 | Ignition Switch On/Start Position Circuit Low | ECM/PCM | Medium |
| P2535 | Ignition Switch On/Start Position Circuit High | ECM/PCM | Medium |
| P2536 | Ignition Switch Accessory Position Circuit | ECM/PCM | Medium |
| P2537 | Ignition Switch Accessory Position Circuit Low | ECM/PCM | Medium |
| P2538 | Ignition Switch Accessory Position Circuit High | ECM/PCM | Medium |
| P2539 | Low Pressure Fuel System Sensor Circuit | ECM/PCM | Medium |
| P2540 | Low Pressure Fuel System Sensor Circuit Range/Performance | ECM/PCM | Medium |
| P2541 | Low Pressure Fuel System Sensor Circuit Low | ECM/PCM | Medium |
| P2542 | Low Pressure Fuel System Sensor Circuit High | ECM/PCM | Medium |
| P2543 | Low Pressure Fuel System Sensor Circuit Intermittent | ECM/PCM | Medium |
| P2544 | Torque Management Request Input Signal A | Torque Management | Medium |
| P2545 | Torque Management Request Input Signal A Range/Performance | ECM/PCM | Medium |
| P2546 | Torque Management Request Input Signal A Low | ECM/PCM | Medium |
| P2547 | Torque Management Request Input Signal A High | ECM/PCM | Medium |
| P2548 | Torque Management Request Input Signal B | ECM/PCM | Medium |
| P2549 | Torque Management Request Input Signal B Range/Performance | ECM/PCM | Medium |
| P2550 | Torque Management Request Input Signal B Low | ECM/PCM | Medium |
| P2551 | Torque Management Request Input Signal B High | ECM/PCM | Medium |
| P2552 | Throttle/Fuel Inhibit A Circuit | ECM/PCM | Medium |
| P2553 | Throttle/Fuel Inhibit A Circuit Range/Performance | ECM/PCM | Medium |
| P2554 | Throttle/Fuel Inhibit A Circuit Low | ECM/PCM | Medium |
| P2555 | Throttle/Fuel Inhibit A Circuit High | ECM/PCM | Medium |
| P2556 | Engine Coolant Level Sensor/Switch Circuit | ECM/PCM | Medium |
| P2557 | Engine Coolant Level Sensor/Switch Circuit Range/Performance | ECM/PCM | Medium |
| P2558 | Engine Coolant Level Sensor/Switch Circuit Low | ECM/PCM | Medium |
| P2559 | Engine Coolant Level Sensor/Switch Circuit High | ECM/PCM | Medium |
| P2560 | Engine Coolant Level Low | ECM/PCM | Medium |
| P2561 | A/C Control Module Requested MIL Illumination | ECM/PCM | Medium |
| P2564 | Turbocharger Boost Control Position Sensor A Circuit Low | Charging System | High |
| P2565 | Turbocharger Boost Control Position Sensor A Circuit High | Charging System | High |
| P2566 | Turbocharger Boost Control Position Sensor A Circuit Intermittent | Charging System | High |
| P2567 | Direct Ozone Reduction Catalyst Temperature Sensor Circuit | ECM/PCM | Medium |
| P2568 | Direct Ozone Reduction Catalyst Temperature Sensor Circuit Range/Performance | ECM/PCM | Medium |
| P2569 | Direct Ozone Reduction Catalyst Temperature Sensor Circuit Low | ECM/PCM | Medium |
| P2570 | Direct Ozone Reduction Catalyst Temperature Sensor Circuit High | ECM/PCM | Medium |
| P2571 | Direct Ozone Reduction Catalyst Temperature Sensor Circuit Intermittent/Erratic | ECM/PCM | Medium |
| P2572 | Direct Ozone Reduction Catalyst Deterioration Sensor Circuit | ECM/PCM | Medium |
| P2573 | Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Range/Performance | ECM/PCM | Medium |
| P2574 | Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Low | ECM/PCM | Medium |
| P2575 | Direct Ozone Reduction Catalyst Deterioration Sensor Circuit High | ECM/PCM | Medium |
| P2576 | Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Intermittent/Erratic | ECM/PCM | Medium |
| P2577 | Direct Ozone Reduction Catalyst Efficiency Below Threshold | ECM/PCM | Medium |
| P2578 | Turbocharger/Supercharger Speed Sensor A Circuit | Charging System | High |
| P2579 | Turbocharger/Supercharger Speed Sensor A Circuit Range/Performance | Charging System | High |
| P2580 | Turbocharger/Supercharger Speed Sensor A Circuit Low | Charging System | High |
| P2581 | Turbocharger/Supercharger Speed Sensor A Circuit High | Charging System | High |
| P2582 | Turbocharger/Supercharger Speed Sensor A Circuit Intermittent | Charging System | High |
| P2583 | Cruise Control Front Distance Range Sensor Single Sensor or Center | ECM/PCM | Medium |
| P2584 | Fuel Additive Control Module Requested MIL Illumination | ECM/PCM | Medium |
About Computer Codes
This page lists all 427 OBD-II diagnostic trouble codes classified under the Computer category. These codes are stored by your vehicle's onboard computer when a sensor detects a malfunction in the computer system. Each code begins with a letter indicating the system (P for Powertrain, B for Body, C for Chassis, U for Network) followed by four digits that identify the specific fault.
When your check engine light comes on, an OBD-II scanner reads these stored codes to help pinpoint the problem. Generic codes (where the second digit is 0) follow the SAE J2012 standard and mean the same thing on every vehicle. Manufacturer-specific codes (where the second digit is 1) may have different meanings depending on the vehicle brand.
Click any code in the table above to see its full description, possible causes, common symptoms, and step-by-step repair guidance. Use the search box to quickly find a specific code within this category.