MCAC-RTSM-2012-07 M-thermal Technical Manual (part 4)
D. "E4": Outdoor temperature sensor error
Method of
malfunction
detection
Check whether T3 and T4 temperature sensor cable are connected correctly.
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.
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
Replace the temperature sensor
Replace the main control
board.