3--3
©
2012 Mobile Climate Control
T-348 Rev. 07/2012
Table 3-2 Alarm Codes
ALARM
NO.
TITLE
CAUSE
REMEDY
CONTROLLER
RESPONSE
A11
Coil Freeze
Coil temperature is less
than 32
°
F and the com
pressor is operating.
Check causes of coil
freezing. (Refer to sec
tion 3.3.7)
An alarm will be generated
and the system will shut
down. The evaporator fans
will remain running while
the compressor is off.
A12
High Voltage
The battery voltage is
greater than 32 volts.
Check, repair or replace
alternator.
The system is shut down
until the voltage returns to
normal levels.
A13
Low Voltage
The battery voltage is
less than 17 volts.
Check, repair or replace
wiring or alternator.
The system is shut down
until the voltage returns to
normal levels.
A14
Return Air Probe Failure
Return air temperature
sensor failure or wiring
defective.
Ensure all connectors are
plugged in. Check sensor
resistance or wiring. Re
fer to paragraph 4.16.
Replace sensor or repair
wiring.
All outputs except the evap
orator fans will be de-ener
gized.
A15
Suction Pressure
Transducer Failure
Suction pressure trans
ducer failure or wiring
defective.
Ensure all connectors are
plugged in. Check sensor
voltage or wiring. Re
place sensor or repair
wiring.
Both unloaders are ener
gized.
A16
Discharge Pressure
Transducer Failure
Discharge pressure trans
ducer failure or wiring
defective.
Ensure all connectors are
plugged in. Check sensor
voltage or wiring. Re
place sensor or repair
wiring.
One unloader is energized.
Condenser fans will run on
high speed.
A17
Low Pressure Shutdown
Low suction pressure
switch open or wiring
defective.
Check cause of low suc
tion pressure. (Refer to
section 3.3.4)
The clutch is de-energized
for the minimum off time.
The evaporator fans will re
main running during this
period. After the compres
sor cycles off three times in
30 minutes all outputs will
be de-energized (except for
the evaporator fans and
heat) and the system is
locked out until the power
is cycled or the alarm is re
set.
A21
High Discharge Pressure
High discharge pressure
switch open or wiring
defective.
Check discharge pressure
transducer reading, wir
ing or cause of high dis
charge pressure. (Refer
to section 3.3.4)
The clutch is de-energized
for the minimum off time.
The condenser and evapo
rator fans will remain run
ning during this period. Af
ter the compressor cycles
off three times in 30 min
utes all outputs will be de-
energized (except for the
evaporator fans and heat)
and the system is locked out
until the power is cycled or
the alarm is reset.
