Owner's Manual

TROUBLE DIAGNOSIS
MTC-69
C
D
E
F
G
H
I
K
L
M
A
B
MTC
Revision: March 2005 2005 Altima
Both High- and Low-pressure Sides are Too Low
Low-pressure Side Sometimes 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 receiver
drier outlet and inlet. Outlet
temperature is extremely
low.
● Liquid tank inlet and expan-
sion valve are frosted.
Liquid tank inside is slightly
clogged.
● Replace desiccant assem-
bly.
● Check lubricant for contami-
nation.
● Temperature of expansion
valve inlet is extremely low
as compared with areas
near liquid tank.
● Expansion valve inlet may
be frosted.
● Temperature difference
occurs somewhere in high-
pressure side
High-pressure pipe located
between receiver drier and
expansion valve is clogged.
● Check and repair malfunc-
tioning parts.
● Check lubricant for contami-
nation.
Expansion valve and liquid
tank are warm or only cool
when touched.
Low refrigerant charge
↓
Leaking fittings or components
Check refrigerant for leaks.
Refer to Checking Refrigerant
Leaks, MTC-102, "
Checking
for Refrigerant Leaks" and
MTC-103, "
Electronic Refrig-
erant Leak Detector" .
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 thermal
valve
3. Outlet and inlet may be
clogged.
● Remove foreign particles by
using compressed air.
● 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 thermo control amp.
and intake sensor operation.
● Replace compressor.
AC353A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.
● Air conditioning system
does not function and does
not cyclically cool the com-
partment air.
● The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.
Refrigerant does not dis-
charge cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refriger-
ant.
● Drain water from refrigerant
or replace refrigerant.
● Replace desiccant assem-
bly.
AC354A