Troubleshooting
Diagnostic Procedure for Check Code
77
14
Check code
Operation cause
1. Outdoor unit service valve closed
2. Cooling bypass PMV error
[A6]
3. TD sensor error
Discharge temperature TD1 alarm
4. Insufficient refrigerant, blockage in pipe
5. Blockage of PMV assembly on the liquid line
Are the gas pipe and liquid
pipe service valves of the
outdoor unit fully open
?
Is there a blockage
in the PMV assembly on
the liquid line
?
Are the resistance characteristics
of TD1 sensor normal
?
Is wiring correct
?
Open valves fully.
Replace TD1 sensor.
Correct wiring.
Cooling bypass PMV B error.
Replace both the PMVs.
No
Yes
Yes
No
Is the cooling bypass
PMV B normal
?
No
Yes
No
Yes
No
Yes
Insufficient refrigerant,
blockage, pipe breakage.
(Check miswiring of the outdoor unit according to miswiring check function.)
Summary of Contents for MM-A0160HX
Page 1: ...Service Manual Air Conditioner Multi Split Type System Modular Multi System HFCR407C A90 0130 ...
Page 2: ......
Page 133: ...134 20 Additional Literature and Contacts ...
Page 134: ...135 20 Additional Literature and Contacts ...
Page 135: ...TOSHIBA AIR CONDITIONING www toshiba aircon co uk MADE IN UK A90 0130 Revised April 2001 ...
