Carrier 68G5-105 Series - SECTION 3 TROUBLESHOOTING; Microprocessor Error Message Definition; Display Error Message Definition; Driver Display Panel Alarm Message Definition

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SECTION 3
TROUBLESHOOTING
CAUTION
Do not under any circumstances attempt to service the microprocessor. Should a problem develop
with the microprocessor, replace it.
NOTE
To access LED display on the microprocessor, remove cover
from main control box located in rear of electrical compartment.
Table 3-1. Microprocessor Error Message Definition
ERROR
CODE
STATUS OF
LED DISPLAY
REMEDY
0 1secon-1secoff Not Applicable as system is operating normally.
1 1 flash - 5 sec pause Record error code number, tag and replace the microprocessor.
2 2 flashes - 5 sec pause Record error code number, tag and replace the microprocessor.
3 3 flashes - 5 sec pause Record error code number, tag and replace the microprocessor.
4 4 flashes - 5 sec pause Record error code number, tag and replace the microprocessor.
5 5 flashes - 5 sec pause Record error code number, tag and replace the microprocessor.
6 6 flashes - 5 sec pause Record error code number, tag and replace the microprocessor.
Table 3-2. Display Error Message Definition
ERROR
CODE
MESSAGE MESSAGE DEFINITION
Er4 Communications Failure If the display does not receive data from the microprocessor.
Er5 Data Memory If memory on the display is not verifie d on power up.
Er6 Program Memory If program memory on t he display is not verifi ed on power up by a checksum.
Table 3-3. Driver Display Panel Alarm Message Definition
ALARM
NO.
TITLE CAUSE REMEDY MICROPROCESSOR RESPONSE
A11 Main Left
Probe Failure
Sensor is unplugged,
wiring defective or
main left evaporator
return air temperature
sensor failure.
Ensure sensor is
plugged in. Check
sensor resistance or
wiring. Replace sen-
sororrepairwiring.
(Refer to section 4.13
and Table 4-3.)
Switches to the right probe. If both
probes are bad, the microprocessor
will run in the full reheat and evapo-
rator fans will operate on low speed.
The compressor will operate on six
cylinders if pressures permit.
A12 Main R i ght
Probe
Failure
Sensor is unplugged,
wiring defective or
main right evaporator
return air temperature
sensor failure.
Ensure sensor is
plugged in. Check
sensor resistance or
wiring. Replace sen-
sororrepairwiring.
(Refer to section 4.13
and Table 4-3.)
Switches to the left probe. If both
probes are bad, the microprocessor
will run in the full reheat and evapo-
rator fans will operate on low speed.
The compressor will operate on six
cylinders if pressures permit.