Alarm Mode Sequence Of Operation - When an alarm fault occurs, the GSC performs the following steps.
- The GSC activates the alarm mode.
- The fault alarm indicator FLASHES.
- When the alarm codes key is pressed, the corresponding diagnostic code (CID FMI) is shown on the upper display.
- The engine continues to run or the engine is able to start.
Shutdown Mode Sequence Of Operation - When a shutdown fault occurs, the GSC performs the following steps.
- The GSC activates shutdown mode.
- The fault shutdown indicator FLASHES.
- The corresponding diagnostic code (CID FMI) is immediately shown on the upper display.
- The engine is shut down or the engine cannot be started.
The diagnostic fault code (CID FMI) closely identifies the cause of the fault. Each diagnostic fault consists of two identifiers and an indicator. The identifiers are shown on the upper display. Service personnel interpret the identifiers in order to assist with troubleshooting.
The indicators are listed below.
Component Identifier (CID) - The CID is a three digit code. The code that is indicated corresponds to a faulty component. The CID is shown on the upper display. For example if the engine magnetic pickup (MPU) is faulty then "190"would be displayed. See the Testing And Adjusting, "Diagnostic Fault Codes" for a list of CID codes.
Control System Identifier - The control system identifier is a single digit. There are two possible control systems that can generate a diagnostic code. If an "E" is showing on the display, the engine ECM has generated the diagnostic code. If there is no "E" on the display, the GSC has generated the diagnostic code.
Failure Mode Identifier (FMI) - The FMI is a two digit code. The FMI tells the type of failure that has occurred. The FMI is shown on the upper display at the same time as the CID. For example, FMI "3" means that the signal voltage is too high. See Testing And Adjusting, "Diagnostic Fault Codes" for a list of FMI codes.
DIAG indicator - When "DIAG" is FLASHING, the diagnostic fault code (CID FMI) that is showing on the upper display is active. When "DIAG" is ON CONTINUOUSLY, there is an inactive diagnostic fault. The CID and the FMI will be recorded in the fault log. Also, see System Operation, "Fault Log Viewing OP1". When the"DIAG" display is not showing then there are NO diagnostic fault codes.
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| Illustration 1 | g00606749 |
Upper Display that is showing a "CID 190 FMI 3" Diagnostic Fault Code | |
Note: The GSC response (alarm or shutdown) to four diagnostic faults is programmable by service personnel. The response that is usually programmed into the GSC is for an alarm. P04 would then be "0". When a shutdown response is programmed P04 would be "1". See Setpoint P04 within Systems Operation, "Engine/Generator Programming OP5". The diagnostic faults that can be programmed are oil pressure sensor CID 100, coolant temperature sensor CID 110, coolant loss sensor CID 111 and sensor power supply CID 269.
The GSC has a fault log to help with troubleshooting of diagnostic faults. Inactive diagnostic fault codes (CID FMI) are recorded in the fault log for viewing at a later time. The total number of faults are shown on the upper display with the CID codes and the FMI codes. An active diagnostic alarm fault becomes inactive when the fault is no longer present and the ECS must be turned to OFF/RESET. The GSC stores a maximum of 12 diagnostic fault codes in the fault log. If an additional diagnostic fault becomes inactive, the GSC automatically clears the earliest diagnostic fault code. This fault code is put into the fault log by the GSC. Inactive diagnostic fault codes that are more than 750 hours old are cleared automatically by the GSC. Only diagnostic fault codes are recorded in the fault log. AL fault codes and SP fault codes are not recorded in the fault log. See Service Manual, "Fault Log Viewing OP1".
Clear diagnostic fault codes from the fault log after correcting the fault. Clearing old codes will help avoid confusion. When all diagnostic faults are cleared from the fault log and no active diagnostic faults exist, the DIAG indicator is OFF. See System Operation, "Fault Log Clearing OP4".