Mitsubishi Electric EHPT20Q-VM2EA Service Manual page 40

Error code Title and display conditions
P1 Indoor unit temperature thermistor (TH1) failure
P2 Indoor unit temperature thermistor (TH2) failure
E0/E4 Main remote controller communication failure
(Reception error)
Error code E0 is displayed if main remote control-
ler does not receive any signal from the indoor
unit for ref. address "0" for 3 minutes.
Error code E4 is displayed if indoor unit does not
receive any data from the main remote controller
for 3 mins or indoor unit does not receive any sig-
nal from the main remote controller for 2 minutes.
E3/E5 Main remote controller communication failure
(Transmission error)
Error code E3 is displayed if the main remote
controller can not find an empty transmission path
and thus fails to transmit for 6 secs or the data
received by the main remote controller is different
to what was sent (by the main remote controller)
30 consecutive times.
Error code E5 is displayed if the FTC can not find
an empty transmission path for 3 minutes and
thus cannot transmit or the data sent by the FTC
is different to what was expected 30 consecutive
times.
E6 Indoor/outdoor communication failure
(Reception error)
Error code E6 is displayed if after the power is
switched ON to the indoor unit, the FTC board
does not receive any signal or the signal received
is not complete for 5 seconds, or after a period of
operation the FTC board does not receive any
signal or the signal received is not complete for 3
minutes.
E7 Indoor/outdoor communication failure
(Transmission error)
Error code E7 is displayed if despite the FTC
board sending signal "0", signal "1" is received
30 consecutive times.
E1/E2
Main remote controller control board failure
Error code E1 displayed if main remote controller
can not access it is non volatile (non power de-
pendent) memory.
Error code E2 is displayed when there is a fault
with the main remote controller's internal clock.
GCH15010
Possible Cause
Refer to error codes (P1/L5).
Refer to error codes (P1/L5).
1. Contact failure with transmission cable
2. Wiring procedure not observed.
(Cable length/cable diameter/number
of indoor units/number of main remote
controllers)
3. Fault on the indoor unit FTC board
section controlling Ref. address "0"
4. Fault with the main remote controller
circuit board
5. Electrical noise causes interference
with transmission/reception of data for
main remote controller.
1. 2 or more main remote controllers have
been connected to the FTC.
2. Fault with main remote controller
transmission/receiving circuit board
3. Fault with the main remote controller
circuit board
4. Electrical noise causes interference
with transmission/reception of data for
main remote controller.
1. Contact failure/short circuit/miswiring
2. Fault with outdoor unit transmission/
receiving circuit board
3. Fault with FTC transmission/receiving
circuit board
4. Electrical noise causes interference
with FTC-Outdoor unit transmission
cable.
1. Fault with FTC transmission/receiving
circuit board
2. Electrical noise causes interference
with power supply.
3. Electrical noise causes interference
with FTC-outdoor unit transmission ca-
ble.
1. Fault with the main remote controller
circuit board
40
Diagnosis and action
1. Check that main remote controller cable
is not extended.
2. Check main remote controller and FTC
common wiring max cable length 500 m.
Only use 2 core cable.
Only connect 1 main remote controller to 1
FTC indoor unit board.
3. to 5.
If the problem is not solved by the above
measures then:
Turn the power to the indoor unit OFF and
then ON.
Power to both the indoor unit and outdoor
unit should be switched OFF then ON.
If the E0/E4 code is still displayed the FTC
and/ or the main remote controller circuit
board should be replaced.
1. Only connect 1 main remote controller to 1
FTC indoor unit board.
2. to 4.
Turn the power to the indoor unit OFF and
then ON.
Power to both the indoor unit and outdoor
unit should be switched OFF then ON.
If the E3/E5 code is still displayed the FTC
and/or the main remote controller circuit
board should be replaced.
* Check the LED display on the outdoor unit
circuit board.
Refer to the outdoor unit service manual.
1. Check the connections on the indoor and
outdoor unit have not become loose and
that the connecting cable is not damaged.
Check that there is not false wiring.
2. to 4.
Turn the power to the indoor unit OFF and
then ON.
Power to both the indoor unit and outdoor
units should be switched OFF then ON.
If the E6 code is still displayed the FTC and/
or the outdoor unit circuit board should be
replaced.
1. to 3.
Turn the power to the indoor unit OFF and
then ON.
Power to both the indoor unit and outdoor
unit should be switched OFF then ON.
If the E7 code is still displayed the FTC cir-
cuit board should be replaced.
1. Replace main remote controller circuit
board.