TM 9-2540-207-14&P
SECTION 6
TROUBLESHOOTING
This section explains the diagnostic system used by the A-20 Global Heater to aid in the determination and repair of
heater malfunctions, as well as guides the user through a step by step procedure to rectify problems based on the
particular diagnostic code given.
6.1
DIAGNOSTIC FAULT CODES
Note: operating codes 00 to 07, 14 and 99, as well as Data Codes D1, D2, and D3
are displayed as part of normal operation and do not require any maintenance
actions.
To assist Heater maintenance, a diagnostic system has been developed to isolate the problem area. This section gives a
brief explanation of the fault codes used by the A-20 Global Heater.
Three different types of Diagnostic Fault Codes are used: Component Failure Codes ("C"), Operating Error Codes ("E",
and Operating Faults ("F').
Note: pp - (i.e. NO DISPLAY) If the Diagnostic Display appears blank and the
Heater is operating, the Diagnostic Display circuit has failed, see 5.5.2.
6.1.1 "C" Codes - Component Failures
Component Failure codes are designed to identify hardware faults.
C1
Igniter Fault
C2
Igniter Short
C3
Vent Fan Fault
C4
Burner Fan Fault
C5
Burner/Exhaust
Sensor Fault
C6
Vent Sensor Fault
C7
Fuel Pressure Sensor Fault
C8
Controller Fault
C9
Fuel Pump Fault
CA
Fuel Injector Fault
6.1.2 "E" Codes - Operating Errors
Operating Error codes are used to display faults which have a direct effect on the heater but which are generally
caused by the vehicle or testing system (i.e. external to Heater)
E1
Low Voltage
E2
Low Fuel Pressure
E3
Low Burner Air Flow
E4
Reverse Burner Air Flow
E5
Inlet Over Pressure
E6
Over Voltage
6.1.3 "F" Codes - Operating Faults
Operating Faults are heater failures caused by operation of the Heater outside the standard Heater operating
parameters.
F1
Ignition Overtime
F2
Burner Flame Out
F3
Heat Limit
F4
Vent Air Over Heat
F5
Over Current
F6
Ambient Over Temperature
F7
Exhaust Over Temperature
F8
Ignition Flame Out
6-1
