Nissan Frontier D22. Manual - part 833

MTC-54

TROUBLE DIAGNOSIS

High-Pressure Side is Too High and Low-Pressure Side is Too Low.

High-Pressure Side is Too Low and Low-Pressure Side is Too High.

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

High-pressure side is too high and 
low-pressure side is too low.

Upper side of condenser and 
high-pressure side are hot, 
however, liquid tank is not so 
hot.

High-pressure tube or parts 
located between compressor 
and condenser are clogged or 
crushed.

●

Check and repair or replace 
malfunctioning parts.

●

Check lubricant for contami-
nation.

AC360A

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

High-pressure side is too low and 
low-pressure side is too high.

High and low-pressure sides 
become equal soon after 
compressor operation stops.

Compressor pressure opera-
tion is improper.

↓

Damaged inside compressor 
packings

Replace compressor.

No temperature difference 
between high and low-pres-
sure sides

Compressor pressure opera-
tion is improper.

↓

Damaged inside compressor 
packings.

Replace compressor.

AC356A

TROUBLE DIAGNOSIS

MTC-55

C

D

E

F

G

H

I

K

L

M

A

B

MTC

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.

Compressor discharge capac-
ity does not change. (Com-
pressor stroke is set at 
maximum.)

●

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 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 compo-
nents

Check refrigerant for leaks. 
Refer to 

MTC-72, "Checking 

for Refrigerant Leaks"

 .

There is a big temperature dif-
ference between expansion 
valve inlet and outlet while the 
valve itself is frosted.

Expansion valve closes a lit-
tle compared with the specifi-
cation.

↓

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.

↓

Compressor discharge capac-
ity does not change. (Com-
pressor stroke is set at 
maximum length.)

●

Check intake sesor opera-
tion. Refer to 

MTC-60, 

"Intake Sensor"

 .

●

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 refriger-
ant or replace refrigerant.

●

Replace liquid tank.

AC354A

MTC-56

TROUBLE DIAGNOSIS

Low-Pressure Side Becomes Negative.

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Low-pressure side becomes nega-
tive.

Liquid tank or front/rear side 
of expansion valve's pipe is 
frosted or dewed.

High-pressure side is closed 
and refrigerant does not flow.

↓

Expansion valve or liquid tank 
is frosted.

Leave the system at rest until 
no frost is present. Start it 
again to check whether or not 
the problem is caused by 
water or foreign particles.

●

If water is the cause, initially 
cooling is okay. Then the 
water freezes causing a 
blockage. Drain water from 
refrigerant or replace refrig-
erant.

●

If due to foreign particles, 
remove expansion valve 
and remove particles with 
dry and compressed air (not 
shop air).

●

If either of the above meth-
ods cannot correct the 
problem, replace expan-
sion valve.

●

Replace liquid tank.

●

Check lubricant for contami-
nation.

AC362A

TROUBLE DIAGNOSIS

MTC-57

C

D

E

F

G

H

I

K

L

M

A

B

MTC

Insufficient Heating

EJS0020C

TROUBLE DIAGNOSIS PROCEDURE FOR INSUFFICIENT HEATING

Symptom:

●

Insufficient heating

Inspection Flow

WJIA0283E

*1:

MTC-58

*2:

MTC-30

*3:

MTC-22

*4:

CO-13

 (KA24DE models) or 

CO-28

  

(VG33E and VG33ER models)

*5:

MA-16

 (KA24DE models) or 

MA-26

  

(VG33E and VG33ER models)

*6:

MTC-63

*7

CO-8

 (KA24DE models) or 

CO-23

  

(VG33E and VG33ER models)