R410A All DC Inverter V4+S Series 60Hz MCAC-VTSM-2015-09
136 Troubleshooting
4.3 E4: Malfunction of outdoor ambient temperature sensor (T4)
4.4 E7: Malfunction of discharge temperature sensor
The error will only display on faulty unit, all the ODUs will be on standby.
E4/E7: Malfunction of temperature
sensor
Connection ports for temperature
sensor on main PCB are loose
Fasten the temperature sensor
ports
Temperature sensor is short circuited
or disabled (Use a multi-meter to
measure resistance, if the resistance is
too low, the sensor is short circuited, if
the resistance in certain temperature is
not consistent with attached table 1or
2, the sensor is disabled)
Outdoor main PCB is damaged
Replace the outdoor main PCB