In adjusting temp switch from 32°C to 17°C, 11V is outputted from FATC connector A-9 terminal, 0V is supplied for A-22
terminal and temp motor works in direction of COOL. In adjusting temp switch from 17°C to 32°C, 11V is outputted from
FATC connector A-22 terminal, 0V is supplied for A-9 terminal and temp motor works in direction of WARM. When temp
actuator has to move to a certain location for its automatic control, temp feedback signal terminal moves equally in temp
actuator and informs controller of location of temp actuator through FATC connector B-10 terminal. Comparing original
value with inputted value, it works until they are same. If 4.9V and more is inputted in B-10 terminal, it is regarded as
disconnection. If 0.1V and less is inputted in B-10 terminal, it is regarded as short-circuit. In the case of disconnection or
short-circuit as a result of self-diagnostic, substitute control is carried out as follows.
ERROR DIAGNOSTICS
TEMP CHECK
• If setup temperature is 17°C to 24.5°C, set to MAX COOL.
• If setup temperature is 25°C to 32.0°C, set to MAX WARM.
Symptoms
Causes
How to check
Temp actuator running error
Power supply error in temp actuator
After altering 17°C to 32°C and advers ely,
measure voltage ofA-22 terminal. If Both of
them are 9V and more, check temp actuator
and peripheral wiring state and if one or
both of them are 5V and less, its cause is
internal failure of FATC.
Sensor (+5) power supply error
If automatic control isn't operated smoothly,
measure voltage of FATC connector B- 8
terminal. If under 4.8V or over 5.2V, its
cause is internal failure of FATC.
Driver error of temp actuator
If No. 20 is outputted as a result of self-
diagnostic, check temp actuatordriver.
Page 7 of 8
24.04.2008
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