| The pressure in line | possible cause |
| Low pressure only in D | Hydraulic failure to position D |
| Low pressure only at position R | Malfunction of the hydraulic system for the R position |
| Low pressure only at positions D and S | Sticking a pressure regulating valve |
| Improper operation of the primary control valve |
| Wear oil pump |
| Malfunction of the hydraulic brake lines downshift |
| Pressure above this | Sticking a pressure regulating valve |
| Improper operation of the primary control valve |