ARMY TM 9-6115-671-14 AIR FORCE TO 35C2-3-446-32 MARINE CORPS TM 09249A/09246A-14    2-13 TABLE 2-4.  DIAGNOSTIC CONTROLS AND INDICATORS (continued) KEY CONTROL OR INDICATOR FUNCTION BACKPLANE MODULE (continued) 20 LED 13 (red) indicator Short circuit indication.  If indicator is lit, indicates a short circuit condition affecting generator set output has been detected. 21 LED 12 (green) (not assigned) 22 LED 11 (green) Remote display connection.  Indicator blinks on and off when remote display is properly connected.  If not lit, indicates no remote display connection has been made. 23 LED 10 (green) Data validity from remote display.  Indicator blinks on and off to indicate remote data is being received properly.  If not lit, remote data is not being received properly.  If not lit, can also indicate no remote display function has been connected. 24 LED 9 (green) Status of the main generator power bus.  If indicator is lit, the bus is energized (voltage is present), and voltage is available for paralleling operation.  If not lit, indicates the generator set is operating in a stand-alone mode. 25 LED 8 (red) (not assigned) 26 LED 7 (red) Network failure.  If indicator is lit, indicates the CIM is not communicating with the I/O interface module.  If not lit, indicates the CIM is communicating properly. 27 LED 6 (red) Emergency stop.  If indicator is lit, indicates the EMERGENCY STOP switch has been activated.  If not lit, indicates normal running condition. 28 LED 5 (red) CMOS voltage.  If indicator is lit, indicates voltage necessary for CMOS device operation is too low.  If not lit, CMOS device voltage source is sufficient. 29 LED 4 (green) (not assigned) 30 LED 3 (green) Heartbeat.  If indicator is blinking on and off, indicates proper operation of this module.  If not lit, indicates module has no power applied or has failed. 31 LED 2 (green) (not assigned) 32 LED 1 (green) If indicator is lit, fuel pump is operating.  If not lit, fuel pump is not operating. AUTOMATIC VOLTAGE REGULATOR 33 AC SENSING (green LED) This indicator is normally lit, indicating the AC sensor is sending the proper signal to this module. 34 DC SUPPLY indicator (green LED) This indicator is normally lit, indicating that the module's internal DC supply is operating.  The source for input power to this module is the AC output of the generator set.  Therefore, the indicator will not be lit until the generator set is providing power output to a load. 35 FIELD VOLTAGE (green LED) This indicator is normally lit.  It indicates field voltage is present, which means the generator is developing AC power.