HARNESS AS-LIGHTING 4391583 - Caterpillar

codes alert the operator that a problem exists. Diagnostic codes also indicate the nature of the problem to the service technician. Diagnostic codes are displayed on the same screen as:service hours, engine speed, battery voltage, engine oil pressure and engine coolant temperature.When a diagnostic code is displayed there will not be an arrow that is pointing to the currently displayed parameter. The arrow will be replaced by a flashing "dIAG". If several faults are active, the diagnostic codes will be displayed in sequence. The diagnostic code can be cleared from the display by turning the Engine Control Switch (ECS) to the OFF/RESET position. Before attempting a repair, clear the diagnostic code from the display by moving the ECS to the OFF/RESET position. Attempt to restart the engine in order to verify if there is still a fault condition.