Most Common Check Engine light Codes

A list of some of the common check engine light (CEL) codes. However, it's important to note that the frequency of specific codes can vary based on the make, model, and year of the vehicle.

1. P0031 - O2 Sensor Heater Control Circuit Low (Bank 1, Sensor 1)
2. P0037 - O2 Sensor Heater Control Circuit Low (Bank 1, Sensor 2)
3. P0038 - O2 Sensor Heater Control Circuit High (Bank 1, Sensor 2)
4. P0101 - Mass or Volume Air Flow Circuit Range/Performance Problem
5. P0102 - Mass or Volume Air Flow Circuit Low Input
6. P0110 - Intake Air Temperature Sensor Circuit Malfunction
7. P0111 - Intake Air Temperature Sensor Circuit Range/Performance Issue
8. P0128 - Coolant Temperature Below Thermostat Regulating Temperature
9. P0130 - O2 Sensor Circuit Malfunction (Bank 1, Sensor 1)
10. P0131 - O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)
11. P0133 - O2 Sensor Circuit Slow Response (Bank 1, Sensor 1)
12. P0134 - O2 Sensor Circuit No Activity Detected (Bank 1, Sensor 1)
13. P0135 - O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
14. P0136 - O2 Sensor Circuit Malfunction (Bank 1, Sensor 2)
15. P0171 - System Too Lean (Bank 1)
16. P0172 - System Too Rich (Bank 1)
17. P0174 - System Too Lean (Bank 2)
18. P0175 - System Too Rich (Bank 2)
19. P0300 - Random/Multiple Cylinder Misfire Detected
20. P0301 - Cylinder 1 Misfire Detected
21. P0302 - Cylinder 2 Misfire Detected
22. P0303 - Cylinder 3 Misfire Detected
23. P0304 - Cylinder 4 Misfire Detected
24. P0305 - Cylinder 5 Misfire Detected
25. P0306 - Cylinder 6 Misfire Detected
26. P0307 - Cylinder 7 Misfire Detected
27. P0308 - Cylinder 8 Misfire Detected
28. P0325 - Knock Sensor Circuit Malfunction
29. P0335 - Crankshaft Position Sensor A Circuit Malfunction
30. P0340 - Camshaft Position Sensor Circuit Malfunction
31. P0351 - Ignition Coil A Primary/Secondary Circuit
32. P0400 - Exhaust Gas Recirculation (EGR) Flow Malfunction
33. P0401 - Exhaust Gas Recirculation (EGR) Flow Insufficient
34. P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
35. P0421 - Warm Up Catalyst Efficiency Below Threshold (Bank 1)
36. P0430 - Catalyst System Efficiency Below Threshold (Bank 2)
37. P0440 - Evaporative Emission Control System Malfunction
38. P0441 - Evaporative Emission Control System Incorrect Purge Flow
39. P0442 - Evaporative Emission Control System Leak Detected (Small Leak)
40. P0443 - Evaporative Emission Control System Purge Control Valve Circuit
41. P0445 - Evaporative Emission Control System Purge Control Valve Circuit Shorted
42. P0446 - Evaporative Emission Control System Vent Control Circuit
43. P0455 - Evaporative Emission Control System Leak Detected (Large Leak)
44. P0449 - Evaporative Emission Control System Vent Control Circuit
45. P0456 - Evaporative Emission Control System Leak Detected (Very Small Leak) 
46. P0457 - Evaporative Emission Control System Leak Detected (Fuel Cap Loose)
47. P0505 - Idle Control System Malfunction
48. P0700: Transmission Control System Malfunction
49. P0715: Input/Turbine Speed Sensor Circuit Malfunction
50. P0720: Output Speed Sensor Circuit Malfunction
51. P0730: Incorrect Gear Ratio
52. P0750 - P0770: Shift Solenoid Malfunction
53. P0780: Shift Malfunction
54. P0800: Clutch Position Sensor/Switch Circuit Malfunction
55. P0840: Transmission Fluid Pressure Sensor/Switch A Circuit
56. P0868: Transmission Fluid Pressure Low
Please note that these are just examples of common codes and the list is not exhaustive. For specific diagnostic and repair advice, please give us a call or book on line.