3--1
©
2012 Mobile Climate Control
T-348 Rev. 07/2012
SECTION 3
TROUBLESHOOTING
CAUTION
Do not under any circumstances attempt to service the microprocessor. Should a problem de
velop with the microprocessor, replace it.
3.1 SELF DIAGNOSTICS
A self test is performed by the Micromax Logic
Board each time the board is powered up. Errors, if
any, will be indicated and the unit will not be allowed
to start. The error codes can be read by counting the
number of times that the Logic Board STATUS and
CODE
LED's
(see
Figure 1-10)
flash
simultaneously. The Micromate control panel
display will indicate errors with the code ER-#,
where “ER” is the error prefix and # is the error
number.
Table 3-1 Error Codes
CODE
NAME
DESCRIPTION
ER 1
Data Memory
Logic board data memory failure.
ER 2
Program Memory
Logic board program memory failure.
ER 3
A/D
A/D and multiplexer failure.
ER 4
Communication Failure
Failure in communication between the logic board and MDST.
ER 5
Program Memory
Display program memory failure.
3.2 SYSTEM ALARMS
3.2.1 Alarm Codes
The Micromax Logic Board continuously monitors
system parameters and will generate an ALARM if a
parameter exceeds preset limits. Alarms are indicated
and the controller will respond in accordance with
the information provided in Table 3-2. The alarm
codes can be read by counting the number of times
that the Logic Board CODE LED (see Figure 1-10)
flashes. Each alarm code is a two digit number, the
first set of flashes is the first digit and (after a slight
pause) the second set of flashes is the second digit.
The Micromate control panel display will indicate
alarms with the code A-## or i-##, where “A” is an
active alarm prefix, “i” is an inactive alarm prefix and
## is the alarm number. If no alarms are present, the
display will show “---”. To access the alarm codes,
press the UP and DOWN arrow keys at the same
time and hold for 3 seconds. If multiple alarms are
present the user can scroll through each alarm by
pressing the AUTO key. When the end of the alarm
list is reached the display will show “---”. Press
VENT to scroll backward from the latest alarm to
the earliest alarm in the queue. When using the
VENT key to scroll back, only the alarm code will be
shown, the alarm time will not be shown. If the
AUTO key is held down for five seconds while “---”
is displayed all inactive alarms are cleared. A listing of
alarm codes is provided in Table 3-2.
3.2.2 Activation
When alarms are detected, they are placed in an alarm
queue in the order at which they initiated unless the
alarm is already present. Each alarm recorded will
also capture an evaporator hour meter reading
corresponding to the activation time. If the AUTO
key is pressed while an alarm is displayed, the
activation time capture will be shown.
3.2.3 Alarm Queue
The alarm queue consist of 10 alarm locations. When
the alarm queue is full the Logic Board will take the
required action but the alarm will not be recorded.
When this situation occurs, an “Alarm Queue
Full”alarm will be generated. When the alarms are
viewed this will be the first alarm to be shown.
3.2.4 Alarm Clear
The user may clear inactive alarms using the
Micromate control panel keypad. Refer to paragraph
3.2.1.
