TM 9-2540-207-14&P 3.7 WARNING & SHUTDOWN FAULTS If  the  Control  Box  Lamp  begins  to  flash,  the  Heater  is  signaling  that  an  abnormal  condition  is  present.    The  appropriate maintenance  technician  can  correct  this  condition  by  referencing  the  diagnostic  codes  and  instructions  in  Section  6 (TROUBLESHOOTING) of this manual. If a Fuel Pressure Sensor or Low Fuel Pressure Warning Fault, or any of the Shut Down faults is encountered during Start Up  or  ignition  is  not  achieved  in  the  allowable  3  1/2  minutes,  the  Heater  will  enter  Purge  mode,  flash  the  Control  Box Lamp, and display the component fault. If a Warning Fault is encountered during Run operations, the Heater will alternately display the fault code and the current run  code  (07  or  14)  on  the  Diagnostic  Display.    If  possible,  the  Heater  will  adjust  its  operation  to  compensate  for  the condition.  If the condition continues and operation is no longer possible, the Heater will enter Purge mode, and steadily display  the  Warning  fault.    With  the  exception  of  the  Low  Fuel  Pressure  and  Fuel  Pressure  Sensor  Fault  warnings,  the Control Box Lamp will not flash if a Warning fault is displayed.  In the case of a Low Fuel Pressure Fault, the Control Box Lamp  will  flash  in  a  cycle  comprising  two  (2)  quick  flashes  followed  by  a  two  (2)  second  delay.    In  the  case  of  a  Fuel Pressure Sensor Fault, the Control Box Lamp will flash in a cycle comprising three (3) quick flashes followed by a two (2) second delay. If the Shut Down faults in Table 3-7 are encountered, the Heater will cease to attempt a Start Up or, if in Run mode at the time  of  the  fault  occurrence,  will  cease  to  produce  heat  and  will  immediately  enter  the  Shut  Down  and  Purge  modes  to avoid operating in an unsafe condition.  The Diagnostic Display will display the fault code and the Control Box Lamp will flash in a cycle comprising one (1) flash followed by a two (2) second delay. C7 Fuel Pressure Sensor Fault C9 Fuel Pump Fault E2 Low Fuel Pressure E5 Inlet Over Pressure E6 Over Voltage F3 Heat Limit F6 Ambient Over Temperature Table 3-6.  Warning Faults C1 Igniter Fault C2 Igniter Short C3 Vent Fan Fault C4 Burner Fan Fault C5 Burner/Exhaust Sensor Fault C6 Vent Sensor Fault C8 Controller Fault CA Fuel Injector Fault E1 Low Voltage E3 Low Burner Air Flow E4 Reverse Burner Air Flow F1 Ignition Overtime F2 Burner Flame Out F4 Vent Air Over Heat F5 Over Current F7 Exhaust Ove r Temperature F8 Ignition Flame Out Table 3-7.  Shut Down Faults 3-5