Alpha Technologies ECM - Manual (Page 21)

21 TM 744-862-C0-003 Rev.C
Engine Control Module (ECM)
2.1 Indicators
Refer to the illustration on the following page:
The ECM user interface consists of 5 LEDs (2-6), a three-position rocker
switch (7), and a momentary contact, push-button switch (8). The COMM
Interface (1) can be used to attach an Alpha Technologies system controller.
Provisions are made for Transponder connections through the Interface
connector (9).
The Major and Minor alarm LEDs (2,3) are red and reflect the state of the
discrete major and minor alarms monitored by the ECM.
A Major alarm indicates failure of a critical component or some other
situation (pad shear, for example) where the system either has gone off-
line, or system failure and/or shutdown is imminent. Major alarms cause
the engine to shutdown immediately and generally prevent further
operation. Most major alarms are latched by the ECM. A site check by
service personnel is required to repair the fault and clear the system.
A Minor alarm indicates a system fault which, though not indicative of
imminent system failure or shutdown, requires service attention as the
fault condition could worsen to shut down the system. A site check by
service personnel is recommended.
The amber Notify LED (4) represents status information that is not
significant enough to be classified as an alarm. At present, only two items fit
into this category: AC line status and Engine Service Required.
The COMMunications LED (5) illuminates for two seconds after each
communications session on the Alpha bus. This is a standard that is used
throughout the Alpha bus communications system.
The green SYStem status LED (6) indicates that the microprocessor has
power and is operating normally. This LED flashes at a 1 Hz rate with a 50%
duty cycle. When the ECM is in factory test mode, this LED will flash at a 0.5
Hz rate.
NOTE: Early versions of the ECM (prior to 12/99), the Communications
and System Status functions were swapped.
Section 2, ECM Indicators and Control Functions