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 fault shutdown. To show the severity of the fault, the AL fault codes are accompanied by the fault alarm indicator, or the fault shutdown indicator on the GSC. The AL fault codes and the related setpoints are described in the paragraphs that follow.
AL1 High Water Temperature Alarm - The GSC issues a high water temperature shutdown when the engine coolant temperature increases to within 6°C (11°F) of 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 high water temperature shutdown. This setpoint sets the coolant level temperature. The GSC uses the temperature in order to declare that a high water temperature shutdown fault 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 (low water temperature alarm), the GSC issues a 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 low water temperature alarm. This setpoint tells the GSC when to declare that a low water temperature alarm fault "(AL2)" exists.
AL3 Low Engine Oil Pressure Alarm - The GSC issues a low oil pressure alarm when the engine oil pressure drops to within 34 kPa (5 psi) of the P13 setpoint or the P14 setpoint. 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 rated speed. This setpoint tells the GSC when to declare that a low oil pressure shutdown fault exists while the engine is at rated speed. 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. This setpoint tells the GSC+ when to declare a low oil pressure shutdown fault while the engine is at idle speed. When the setpoint is reached, the dedicated shutdown indicator for low oil pressure FLASHES and the engine is shutdown.
AL4 Fault Detected By Engine ECM - 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 includes faults that include derating of the engine. The engine ECM is factory programmed to NOT DERATE in generator set applications. The occurrence of an AL4 fault code could mean that the engine ECM is not programmed correctly. Refer to the Troubleshooting, SENR1003, "3500B EPG Engines". The "AL4" fault (P23) is disabled on MUI engines and gas engines.
When the fault is programmed as a shutdown fault, the fault shutdown indicator will FLASH and the "AL4" fault code is immediately shown on the upper display.
When the fault is programmed as an alarm fault, the fault alarm indicator will FLASH and the AL4 fault code is shown on the upper display after the alarm codes key is pressed.