Mitsubishi Electric EHST20C-VM6HA Service Manual page 48

Error code Title and display conditions
E7 Indoor/outdoor communication failure
(Transmission error)
Error code E7 is displayed if despite the
FTC3 board sending signal "0", signal "1" is
received 30 consecutive times.
E1/E
Main controller control board failure
Error code E1 displayed if main controller
can not access it's non volatile (non power
dependent) memory.
Error code E2 is displayed when there is a
fault with the main controller's internal clock.
J0 Indoor unit/wireless receiver communi-
cation failure
Error code J0 is displayed when the FTC3
can not receive data from the wireless re-
ceiver for 1 min.
J1 to J8 Wireless remote controller/wireless
receiver communication failure
(Reception error)
Error code displayed if wireless receiver
receives no/incomplete data from
the wireless remote controller for 15
consecutive minutes.
The digit after the J refers to the address of
the wireless remote controller that has the
error.
E.g. Error code "J3" refers to a
communication fault between the wireless
receiver and wireless remote control with
address 3.
Note: To cancel error codes please switch system off (press button F4 (RESET) on main controller).
Possible Cause
Fault with FTC3 transmission/receiving
1
circuit board
Electrical noise causes interference with
2
power supply.
Electrical noise causes interference with
3
FTC3-outdoor unit transmission cable.
Fault with the main controller circuit board
1
Connection fault with wireless receiver-
1
FTC3 connection
Fault with FTC3 receiving circuit board
2
Fault with wireless receiver's transmission
3
circuit board
Electrical noise causes interference with
4
wireless receiver communication cable.
Battery on wireless remote control may be
1
flat
The wireless remote controller is out of
2
range of the wireless receiver.
Fault with wireless remote controller
3
transmission circuit board
Fault with wireless receiver's reception
4
circuit board
48
Diagnosis and action
1 3
to
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.
(This may require switching 1 or 2 breakers
depending if the unit is powered independ-
ently from the outdoor unit).
If the E7 code is still displayed the FTC3 cir-
cuit board should be replaced.
1 Replace main controller circuit board.
Check the connections to the wireless re-
1
ceiver and FTC3 have not become loose and
that the connecting cable is not damaged.
2 4
to
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.
(This may require switching 1 or 2 breakers
depending if the unit is powered independ-
ently from the outdoor unit).
If the J0 code is still displayed the FTC3 and/
or the wireless receiver circuit board should
be replaced. replaced.
1 Check and replace the battery if necessary
the wireless remote controller battery.
2 4
to
Reposition the wireless remote control closer
to the receiver and perform a communication
test.
For procedure refer to wireless remote
controller installation manual.
If "OK" is displayed then the cause of the J1 to
J8 error was the controller was out of range of
the receiver.
The wireless remote controller should be
installed within range of the receiver.
If "Err" is displayed replace wireless remote
controller with a new controller and perform
the pairing procedure.
If after this procedure the "Err" code is still
displayed the fault is with the receiver unit
(attached to the indoor unit).
The receiver unit should be replaced with a
new part and the original remote control can
be reconnected.
If "OK" is displayed then the fault is with the
remote control and this should be replaced.