Infiniti FX35 / FX45. Manual - part 121
ATC-80
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
Gauge indication
Refrigerant cycle
Probable cause
Corrective action
Both high- and low-pressure sides
are too low.
• There is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.
• Liquid tank inlet and expan-
sion valve are frosted.
Liquid tank inside is slightly
clogged.
• Replace liquid tank.
• Check lubricant for contami-
nation.
• Temperature of expansion
valve inlet is extremely low
as compared with areas
near liquid tank.
• Expansion valve inlet is
frosted.
• Temperature difference oc-
curs somewhere in high-
pressure side.
High-pressure pipe located be-
tween liquid tank and expan-
sion valve is clogged.
• Check and repair malfunc-
tioning parts.
• Check lubricant for contami-
nation.
Expansion valve and liquid
tank are warm or slightly cool
when touched.
Low refrigerant charge.
↓
Leaking fittings or compo-
nents.
Check refrigerant for leaks.
Refer to
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted.
Expansion valve closes a little
compared with the specifica-
tion.
↓
1.
Improper expansion
valve adjustment.
2.
Malfunctioning expansion
valve.
3.
Outlet and inlet may be
clogged.
• Remove foreign particles by
using compressed air.
• Replace expansion valve.
• Check lubricant for contami-
nation.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet.
Low-pressure pipe is clogged
or crushed.
• Check and repair malfunc-
tioning parts.
• Check lubricant for contami-
nation.
Air flow volume is not enough
or is too low.
Evaporator is frozen.
• Check intake sensor circuit.
Refer to
.
• Replace compressor.
• Repair evaporator fins.
• Replace evaporator.
• Refer to
.
AC353A
Gauge indication
Refrigerant cycle
Probable cause
Corrective action
Low-pressure side sometimes be-
comes negative.
• Air conditioning system does
not function and does not cy-
clically cool the compart-
ment air.
• The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.
Refrigerant does not discharge
cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refrigerant.
• Drain water from refrigerant
or replace refrigerant.
• Replace liquid tank.
AC354A