| Label | Car engine faults |
| y1 | Idle-air valve malfunction |
| y2 | Defective ignition coil |
| y3 | Incorrect ignition timing |
| y4 | Defective spark plug |
| y5 | Defectivethrottle valve |
| y6 | Leakage in intake manifold |
| y7 | Defective air cleaner |
| y8 | Defective injector |
| y9 | Defective fuel pump system |
| y10 | Defective cooling system |
| y11 | Defective lubrication system |