MTC-54
TROUBLE DIAGNOSIS
Revision: June 20062007 Versa
PERFORMANCE CHART
Test Condition
Testing must be performed as follows:
Test Reading
Recirculating-to-discharge Air Temperature Table
Ambient Air Temperature-to-operating Pressure Table
*1: With blower control dial in the "1" position
*2: With blower control dial in the "4" position.
Vehicle condition Indoors or in the shade (in a well-ventilated place)
Doors Closed
Door window Open
Hood Open
TEMP. Max. COLD
Mode control dial
(Ventilation) set
Intake door lever
(Recirculation) set
Blower speedMax. speed set
Engine speed Idle speed
Operate the air conditioning system for 10 minutes before taking measurements.
Inside air (Recirculating air) at blower assembly inlet
Discharge air temperature at center ventilator
°C (°F) Relative humidity
%Air temperature
°C (°F)
50 - 6020 (68) 7.2 - 9.1 (45 - 48)
25 (77) 11.4 - 13.8 (53 - 57)
30 (86) 15.5 - 18.4 (60 - 65)
35 (95) 20.3 - 23.7 (69 - 75)
60 - 7020 (68) 9.1 - 10.9 (48 - 52)
25 (77) 13.8 - 16.2 (57 - 61)
30 (86) 18.4 - 21.3 (65 - 70)
35 (95) 23.7 - 27.1 (75 - 81)
Ambient air
High-pressure (Discharge side)
kPa (bar, kg/cm
2 , psi)Low-pressure (Suction side)
kPa (bar, kg/cm2 , psi) Relative humidity
%Air temperature
°C (°F)
50 - 7020 (68)843 - 1,036 *1
(11.08 - 13.63, 8.6 - 10.6, 122 - 150)159.0 - 194.0
(1.59 - 1.94, 1.62 - 1.98, 23.1 - 28.1)
25 (77)1,094 - 1,338 *1
(10.94 - 13.38, 11.2 - 13.6, 159 - 194)196.3 - 240.0
(1.96 - 2.40, 2.00 - 2.45, 28.5 - 34.8)
30 (86)1,298 - 1,590 *1
(12.98 - 15.90, 13.2 - 16.2, 188 - 231)248.0 - 302.7
(2.48 - 3.03, 2.53 - 3.09, 36.0 - 43.9)
35 (95)1,383 - 1,688 *2
(13.83 - 16.88, 14.1 - 17.2, 201 - 245)308.8 - 377.4
(3.09 - 3.77, 3.15 - 3.85, 44.8 - 54.7)
40 (104)1,628 - 1,988 *2
(16.28 - 19.88, 16.6 - 20.3, 236 - 288)377.4 - 461.2
(3.77 - 4.61, 3.85 - 4.70, 54.7 - 66.8)
TROUBLE DIAGNOSIS
MTC-57
C
D
E
F
G
H
I
K
L
MA
B
MTC
Revision: June 20062007 Versa
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
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 liquid tank.
AC354A
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 malfunction 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 the particles
with dry and compressed air
(not shop air).
If either of the above meth-
ods cannot correct the mal-
function, replace expansion
valve.
Replace liquid tank.
Check oil for contamination.
AC362A
