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 code (CID FMI) closely identifies the cause of the fault. Each diagnostic code 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, a "190" is the code for the circuit for the engine magnetic pickup (MPU). See the Testing And Adjusting, "Troubleshooting Diagnostic Codes" for a list of CID codes.
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, "Troubleshooting Diagnostic Codes" for a list of failure mode identifiers.
DIAG indicator - When "DIAG" is FLASHING, the diagnostic code (CID FMI) that is shown on the upper display is active. When "DIAG" is ON CONTINUOUSLY there is an inactive diagnostic fault. The diagnostic codes are recorded in the fault log. Also, see Systems Operation, "Fault Log Viewing OP1". When "DIAG" is not showing, there are NO diagnostic codes that have been detected.
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| Illustration 1 | g00318043 |
Upper Display That Is Showing A "CID 190 FMI 3" Diagnostic Code | |
The above example shows a diagnosed fault. Also, that fault is sending the information to the GSC for display. The GSC is receiving a signal from the engine speed sensor (CID 190). The signal is too high so the FMI is 3. The signal is being received at this time so "DIAG" is FLASHING.
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 following diagnostic codes are diagnostic faults: pressure sensor (engine oil) (CID 100), temperature sensor (engine coolant) (CID 110), fluid level sensor (engine coolant) (CID 111) and sensor power supply (CID 269).
The GSC has a fault log to help with troubleshooting of diagnostic faults. Inactive diagnostic codes (CID FMI) are recorded in the fault log for viewing at a later time. Also, the number of occurrences are totalled. The number of occurrences are shown on the upper display. The diagnostic codes are also shown on the upper display. An active diagnostic alarm fault is signified by "DIAG" FLASHING on the upper display. When a diagnostic alarm fault becomes inactive "DIAG" is ON CONTINUOUSLY. When the fault is no longer occurring the ECS must be turned to "OFF/RESET". When a diagnostic shutdown fault becomes inactive "DIAG" is ON CONTINUOUSLY. When the fault is no longer occurring the ECS must be turned to "OFF/RESET". The GSC stores a maximum of 12 diagnostic codes in the fault log.
If an additional diagnostic fault becomes inactive, the GSC automatically clears the earliest diagnostic code. The GSC puts the additional diagnostic code in the fault log. Inactive diagnostic codes that are more than 750 engine hours old are cleared automatically by the GSC. Only diagnostic codes are recorded in the fault log. AL fault codes and SP fault codes are not recorded in the fault log. See Systems Operation, "Fault Log Viewing OP1".
Clear diagnostic 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 Systems Operation, "Fault Log Clearing OP4".