MCAC-RTSM-2012-01 M-thermal Technical Manual (part 2)
D. "E4": Outdoor temperature sensor error
Outdoor Unit
Display
E4
Method of
malfunction
detection
Check whether T3 and T4 temperature sensor cable are connected correctly.
Supposed
Causes
1. Temperature sensor cables
don’t connect correctly.
2. The sensor terminal is loose.
3. The sensor circuit is short or open
4. The main control board's clamp diodes are short or open.
Troubleshooting
E4
Is T3 or T4 port on PCB
loose?
Temperature sensor
is short or defective.
The chip's pins do not match
correctly or the chip is defective.
, turn the power on again,
is”E4”displayed?
Insert the chip correctly or replace it with a
fine one
Replace the temperature sensor
Replace the main control
board.
YES
NO
YES
NO
Fasten the port.
YES
NO
