AL Fault Codes rely upon certain setpoints. See Systems Operation, "Service Mode" for more information on setpoints. AL Fault Codes are not stored in the fault log of the GSC. Many of the AL Fault Codes are programmable as a fault alarm or as a shutdown fault. In order to show the severity of the fault, the AL Fault Codes are accompanied by a fault alarm indicator. Also, the fault shutdown indicator on the GSC can accompany an AL Fault Code. The AL Fault Codes and the related setpoints are described in the paragraphs that follow.
AL1 High Water Temperature Alarm - A high water temperature shutdown is issued by the GSC when the engine coolant temperature increases to about 6°C (11°F) from setpoint P15. The fault alarm indicator will FLASH. The AL1 fault code is shown on the upper display after the "Alarm Fault Codes" key is pressed.
P15 is the setpoint for a high water temperature shutdown. This setpoint sets the coolant level temperature. The GSC uses the temperature in order to declare that a shutdown fault due to high water temperature is present. When the setpoint is reached, the dedicated shutdown indicator for high water temperature FLASHES and the engine is shutdown.
AL2 Low Water Temperature Alarm - When the engine coolant temperature decreases to setpoint P16, the GSC issues a low water temperature alarm. Setpoint P16 is the setpoint for the low water temperature alarm. The fault alarm indicator will FLASH and the AL2 fault code is shown on the upper display after the "Alarm Codes" key is pressed.
P16 is the setpoint for the low water temperature alarm. By displaying P16, the GSC indicates a low water temperature alarm fault.
AL3 Alarm for Low Engine Oil Pressure - When the engine oil pressure decreases to within 34 kPa (5 psi) of Setpoint P13 or P14, the GSC issues an alarm for the low engine oil pressure. The fault alarm indicator will FLASH and the "AL3" fault code is shown on the upper display after the "Alarm Codes" key is pressed.
P13 is the setpoint for low oil pressure shutdown at engine rated speed. If the oil pressure falls below this setpoint while the engine is at rated speed, the GSC will declare a low engine oil pressure fault. When the setpoint is reached, the dedicated shutdown indicator for low oil pressure flashes and the engine is shut down.
P14 is the setpoint for low oil pressure shutdown at idle speed. While the engine is at idle speed, Setpoint P14 tells the GSC when to declare a low oil pressure shutdown fault. When the setpoint is reached, the dedicated shutdown indicator for low oil pressure FLASHES and the engine is shutdown.
AL4 Fault Detected By The Engine ECM - (EUI Only) The AL4 fault occurs when the electronic control module (ECM) for the engine detects an alarm fault or a shutdown fault. The engine ECM tells the GSC whether the AL4 fault is an alarm fault or a shutdown fault. This indication includes faults that include derating of the engine. When the engine ECM is used in applications with generator sets, the engine ECM is programmed in the factory NOT to derate. The occurrence of an AL4 fault code could mean that the engine ECM is not programmed correctly. For the particular engine, refer to the Troubleshooting Service Module. The AL4 fault (P23) is disabled on MUI engines and gas engines.