Electronic expansion valve
Split ODU – 6 720 817 722 (2015/06)
37
EEV valve operation
Fig. 35 EEV valve operation
[A]
Valve open angle
[P]
Pulse
[1]
Close
[2]
Open
[3]
Fully open 1350 pulses
• At power ON, open angle signal of 1400 pulses output and valve
position is set to
If valve operates smoothly, no noise and vibration occur and if valve
is closed. Noise occurs.
• Noise from the EEV can be confirmed by touching the EEV surface
with a screw driver and listening to the EEV noise.
• If liquid refrigerant is in EEV, the noise is lower.
EEV failure check method
2
3
a
1
A
P
6 720 817 722-31.1I
a
Failure mode
Diagnosis
Repair process
Remark
Microcomputer driving circuit
failure
1. Disconnect the EEV connector from
control board and connect testing
LED
2. Main power ON, pulse signal is out
from EEV for 17 seconds. If the LEDs
do not turn on, or are in on state
continuously, then the driving circuit
is abnormal
Check and replace unit control
board
Unit
EEV locking
1. If EEV is locked, in no load state, the driving motor rotate
and clicking sound always occurs
Replace EEV
EEV motor coil short or
misconnection
1. Check the resistance between coil terminal (red-white, red-
yellow, red-orange, red-blue)
2. If the estimated resistance value is in 52
3
then the EEV
is normal
Replace EEV
1. Check the resistance between coil terminal (brown-white,
brown-yellow, brown-orange, brown-blue)
2. If the estimated resistance value is in 150
10
then the
EEV is normal
Replace EEV
Table 41 EEV failure check method
1K LED
