Ignition Alarms

The ICM presents ignition diagnostics in the form of visual tools, user-defined alarms and warnings, and a quick-view for active faults.

ALARMS AND WARNINGS


Adjustable alarms and faults are available on the Ignition Alarms screen (Pg. 407). Alarm thresholds on this screen can be configured at any time to trigger fault conditions for the events listed below.


Ignition Alarms Screen

When an alarm occurs, the “Alarms” button in the footer of the display will flash the “Alarm” text and display the current number of alarms. To clear the alarm, the “Reset Alarm” button must be selected from the Alarm View screen (Pg. 41). The overspeed, underspeed, and critical timing error alarms will shut down the engine. The other diagnostic trigger values will cause an alarm but the engine will stay running.

To set a disable a diagnostic trigger, select the relevant button and press “Disable Highlighted Alarm”. A disabled alarm will show “---“ in its value box. Note that “Overspeed RPM” cannot be disabled.

RPM Overspeed


  • “RPM Overspeed” is the setpoint value for a high RPM shutdown
  • This value is configured during the ignition setup process but can be updated at any moment
  • The maximum RPM overspeed setpoint is 3000 RPM

RPM Underspeed


  • “RPM Underspeed” is the setpoint value for a low RPM shutdown
  • Alarm is only engaged after a startup grace period expires
  • Startup grace period is adjustable up to 20 minutes

Spark Duration


  • A spark duration warning can be configured by defining the “Maximum Spark Duration” and “Minimum Spark Duration” values
  • Valid ranges for spark duration are between 0.5 and 20 ms
  • A spark duration fault provides a warning and does not shutdown the ignition

Spark Deviation from Engine Average


  • The spark deviation warning is intended to identify any cylinder or ignition component issues by comparing the individual spark duration with the engine average duration
  • Valid ranges for spark duration deviation are between 0.1 and 10 ms
  • A spark deviation fault provides a warning and does not shutdown the ignition

Maximum Cycle-to-Cycle Variation


  • The cycle-to-cycle variation warning is intended to identify any cylinder or ignition component issues by identifying cylinders that exceed a user-define cycle-to-cycle spark duration threshold
  • Valid ranges for cycle-to-cycle variation are between 0.1 and 10 ms
  • A cycle-to-cycle variation fault provides a warning and does not shutdown the ignition

Maximum Cylinder Misfires


  • If a cylinder’s spark plug is detected to have not sparked properly a misfire count for that cylinder will be incremented
  • The Maximum Cylinder Misfires value gives a threshold value past which an alarm will be triggered
  • The misfire alarm will show a list of cylinders that are over the threshold value

(Built In) Critical Timing Error – Missing Index


  • If the crank TDC index signal has not been detect for 2.0 seconds while the engine is running, the ignition will shutdown and display the fault in the Alarms screen (Pg. 40)
  • Potential causes of this fault include:
  • TDC magnetic pickup installed too far from the trigger bolt to detect
  • Excessive oil and metal shavings on the pole of the TDC magnetic pickup
  • Improper wiring of the TDC magnetic pickup
  • This error will also show similarly in modes that use a camshaft sensor as a TDC reference if that signal is lost for 2.0 seconds


(Built In) Shutdown Alarms


The Ignition has a variety of shutdown diagnostic alarms that are always enabled. After a shutdown, the EIM will evaluate the conditions of the ignition before and after the engine stopping. If an unusual or problematic condition exists, it will trigger an alarm under code ICM007, and will provide additional information to the user as to what might have contributed to the shutdown.


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