12-4
TROUBLESHOOTING
SM BS DCI 1- A.1 GB
12.3.2 Indoor unit diagnosis and corrective actions
No.
Fault
Probable Cause
Corrective Action
1
Sensor failures of all
types
Check sensor connections or
replace sensor
2
Communication
mismatch
Indoor and Outdoor controllers are
with different versions
Replace Indoor controller
3
No Communication
Communication or grounding wiring is
not good.
Check Indoor to Outdoor wiring
and grounding
4
No Encoder
Indoor electronics or motor
Check motor wiring, if ok,
replace motor, if still not ok,
replace Indoor controller.
5
Outdoor Unit Fault
Outdoor controller problem
Switch to Outdoor diagnostics.
6
EEPROM Not
Updated
System is using ROM parameters and
not EEPROM parameters
No action, unless special
parameters are required for
unit operation.
7
Bad EEPROM
No action, unless special
parameters are required for
unit operation.
8
Bad Communication Communication quality is low reliability Check Indoor to Outdoor wiring
and grounding
9
Using EEPROM
data
No problem. System is using
EEPRRRROM parameters
12.3.3
Outdoor Unit Diagnostics
No
Problem
5
4
3
2
1
1
OCT is disconnected
0 0 0 0 1
2
OCT is shorted
0 0 0 1 0
3
CTT is disconnected
0 0 0 1 1
4
CTT is shorted
0 0 1 0 0
5
HST is disconnected (when enabled)
0 0 1 0 1
6
HST is shorted (when enabled)
0 0 1 1 0
7
OAT is disconnected (when enabled)
0 0 1 1 1
8
OAT is shorted (when enabled)
0 1 0 0 0
9
TSUC is disconnected (when enabled)
0 1 0 0 1
10
TSUC is shorted (when enabled)
0 1 0 1 0
11
IPM Fault
0 1 0 1 1
12
Bad EEPROM
0 1 1 0 0
13
DC under voltage
0 1 1 0 1
14
DC over voltage
0 1 1 1 0
15
AC under voltage
0 1 1 1 1
16
Indoor / Outdoor unit Communication mismatch
1 0 0 0 0
17
No Communication
1 0 0 0 1
18
Reserved
1 0 0 1 0
20
Heat sink Over Heating
1 0 1 0 0
21
Deicing
1 0 1 0 1
22
Compressor Over Heating
1 0 1 1 0
23
Compressor Over Current
1 0 1 1 1
…
Reserved
27
Bad Communication
1 1 0 1 1
CONTENTS
