Troubleshooting - Carrier 40GVC Installation Instructions Manual

This unit has on- -board diagnostics. Error codes will appear on the LED display on the front panel of the indoor unit in place of the
temperature display. Error codes are also displayed on the outdoor unit microprocessor board with colored LED lights. The table below
explains the error codes for both units.
Malfunction
Indoor PCB Malfunction
Anti--- freeze Protection
System overload protection
Indoor motor malfunction
Indoor pipe temperature sensor malfunction
Return air temperature sensor malfunction
Indoor board malfunction
Compressor overload protection
Compressor start--- up failure
Outdoor fan motor failure
Low voltage protection
4--- way valve malfunction
Compressor phase detection error
Compressor speed reduction
Current detection malfunction
Outdoor ambient temperature sensor
malfunction
Discharge temperature sensor malfunction
(out of range)
Discharge temperature sensor malfunction
(open or shorted)
Condenser temperature sensor malfunction
(open or shorted)
Heat sink over--- temperature
DC over--- current
Heat sink temperature sensor malfunction
Low charge
DC input voltage is too high
DC input voltage is too low
Communication malfunction
Indoor and outdoor unit mismatched

TROUBLESHOOTING

Diagnostic Codes
38/40GVC/Q 9k / 12k, 115v
Error Code
on indoor unit
EE Replace indoor main board
E2 Outdoor ambient temperature is too low
H4 Check for dirty or blocked heat exchangers
H6 Check motor mounting and wiring
F2 Measure the resistance value in the sensor
F1 Measure the resistance value in the sensor
UF Replace indoor main board
H3 Check overload wiring
Check if the resistance of the compressor and the resistance to
ground is normal. If the resistance is normal, the outdoor main
Lc
board may be defective.
UH Check outdoor motor
E5 Check incoming power
U7 Replace 4--- way valve
U1 Replace outdoor main board
Check if the resistance of the compressor and the resistance to
ground is normal. If the resistance is normal, the outdoor main
H7
board may be defective.
U5 Replace outdoor main board
F3 Measure the resistance value in the sensor
E4 Measure the resistance value in the sensor
F5 Measure the resistance value in the sensor
F4 Measure the resistance value in the sensor
Is outdoor ambient temperature out of system operating range?
P8
Is heat sink blocked or damaged?
UU --- ---
P7 Replace outdoor main board
F0 Check for leaks
PH Check incoming power supply
PL Check incoming power supply
E6 Check wiring connection
UA Check system combination
14
Repair Method/Cause