HOW TO USE ON-BOARD DIAGNOSTICS - CONTINUED
DIAGNOSTIC CODES - CONTINUED
Accessing. To view Logged Event Codes, select Events from the Diagnostics menu, and then select
Logged Event Codes from the sub-menu.
Screen Layout. The Logged Event Codes display area groups the codes according to the ECM from which
they are retrieved. They appear in chronological order by the most recent ECM hour of last occurrence.
The ECM names appear as subtitles in the list. If there is more than one ECM connected, the subtitles are
arranged alphabetically. On the same line as the ECM subtitle, the number of ECM diagnostic clock hours
is displayed. These hours represent the time that the ECM has been connected and running.
The Logged Event Codes screen has five columns: Code, Description, Occ., First, and Last. The code
numbers that appear are used to identify the events. The Description column informs you of the symptom
that is occurring. The Occ. (occurrences) column informs you of the number of times that the symptom
occurred. The columns marked First and Last indicate the first and last ECM hour when the problem
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On some ECMs, a warning category indicator may immediately follow the code number and is in parenthe-
ses. It is a number ranging from 1 to 3, where 3 is the most severe, and it indicates the severity of the associ-
ated code number. The warning category provides an indication to the type of behavior and/or actions
which must be taken by the operator, or by the control system for engine applications, to address the sever-
ity of the associated situation.
When the "Include All ECMs" check box is checked, logged codes from all available ECMs are retrieved
and displayed. When there is a single ECM on the data link, this check box is disabled. The push-buttons
available in the Logged Event Codes screen are: View Histogram and Print.
An event code is generated by detection of an abnormal operating condition. Logged codes may be useful
to help troubleshoot intermittent problems. Logged codes can also be used to review engine and electronic
system performance. For example, an event code will be generated if oil pressure is too low. In this case,
the event code indicates a symptom of a problem. Logged codes may not indicate a repair is needed. The
problem may have been temporary or may have been resolved since logging the code. If the system is
powered, it is possible to generate an active diagnostic code whenever a component is disconnected. When
the component is reconnected, the code is no longer active. Logged events are provided with an indicator
used to keep track of recurring or intermittent events.