Active Diagnostic Codes and Event Codes
An Active diagnostic code represents a problem with the electronic control system. This problem should be corrected as soon as possible. When a active diagnostic code is generated, a display module such as the Caterpillar Monitoring System may produce a warning.
Logged Diagnostic Codes
When the Electronic Control Module (ECM) generates a diagnostic code, the ECM logs the code in permanent memory. The ECM has an internal diagnostic clock. The ECM will record the hour of the first occurrence of the diagnostic code. The ECM will record the hour of the last occurrence of the diagnostic code. The ECM will record the number of occurrences of the code. This information is a valuable indicator for troubleshooting intermittent problems. Any Logged diagnostic codes will automatically be deleted if no additional occurrences are recorded in 100 hours. Some diagnostic codes may be easily triggered. Some diagnostic codes may log occurrences that did not result in complaints. The most likely cause of an intermittent problem is a faulty connection or damaged wiring. The next likely cause is a component failure. The least likely cause is the failure of the ECM. Diagnostic codes that are logged repeatedly may indicate a problem that needs special investigation.
If the symptoms continue, use the proper procedure for troubleshooting the symptoms that have been experienced by the operator.
Note: Always clear logged diagnostic codes after investigating and correcting the problem which generated the code.
Logged Events
The ECM can log events. Events refer to engine operating conditions such as low oil pressure or high coolant temperature. Logged events do not indicate an electronic system problem.
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| Illustration 1 | g00925141 |
The diagram indicates output voltage from a temperature sensor. The Electronic Service Tool can be used to turn these features ON and OFF. When the features are turned ON, the display will appear on an electronic monitoring module and an event will also be logged in the ECM. When the features are turned OFF, the display will not appear on a monitoring module, but an Event will still be logged.
Programmable Engine Parameters
You can program the engine to perform the following actions for some applications:
- Engine Shutdown
- Engine Alarm
The Cat (ET) can be used to activate these features. When the features are activated, the display will appear on an electronic monitoring module. An Event will be logged in the ECM. When the features are not activated, the display will not appear on a monitoring module but an Event will be logged.
Diagnostic Terminology
Module Identifier (MID)
The module identifier (MID) indicates the electronic module that generated the diagnostic code.
- The module identifier (036) indicates the Primary ECM.
- The module identifier (047) indicates the Secondary ECM.
- The module identifier (111) indicates the Integrated Temperature Sensing Module.
- The module identifier (108) indicates the Versatile Control Module.
Failure Mode Identifier (FMI)
- The FMI (00) indicates that the data is above the normal range.
- The FMI (01) indicates that the data is below the normal range.
- The FMI (02) indicates a incorrect signal.
- The FMI (03) indicates that the voltage is above the normal range.
- The FMI (04) indicates that the voltage is below the normal range.
- The FMI (05) indicates that the current is below the normal range.
- The FMI (06) indicates that the current is above the normal range.
- The FMI (07) indicates that there is an improper mechanical response.
- The FMI (08) indicates an abnormal signal.
- The FMI (09) indicates an abnormal update.
- The FMI (10) indicates an abnormal rate of change.
- The FMI (11) indicates that the failure mode is not identifiable.
- The FMI (12) indicates that a device or a component failed.
- The FMI (13) indicates that a component is out of calibration.