
10 Troubleshooting
Troubleshooting procedure
SMGB0091 rev.2 - 11/2015
227
10
Alarm code
21
Abnormality of high pressure sensor
This alarm code is indicated when the pressure sensor output voltage decreases (less than 0.1V) or increases (more
than 4.9V) during the operation.
Is there connection problem of
CN100 on RASC PCB1?
Connect correctly
Yes
No
Is 12V applied between number
1 and 3 of the connector CN100 on
RASC PCB1?
Faulty RASC PCB1
No
Yes
Abnormality of high
pressure sensor
Yes
Is voltage under 0.1V or over
4.9V between number 2 and 3
of the connector CN100 on RASC
PCB1?
Faulty RASC PCB1
No
Phenomenon
Cause
Check item
Action
(Turn OFF Main Switch)
Faulty top of compressor
thermistor
Fault
Check resistance
Replace thermistor if faulty
Incorrect connection
Check wiring to PCB1
Repair wiring and connections
Faulty PCB1
Replace PCB1 and check
operation
Replace PCB1 if faulty
Indication of pressure value is
excessively high or low
Malfunction of pressure sensor
due to clogging wiring
-
Replace pressure sensor