AIR CONDITIONING (OPTIONAL) 1B-13
Detail diagnosis table (at ambient temperature within 30 - 35 °C (85 - 95 °F))
Condition Possible Cause Correction
MANIFOLD
GAUGEMPa
(kg/cm
2)
(psi)Detail
Lo Hi
0.23 - 0.35
(2.3 - 3.5)
(33 - 50)1.4 - 1.75
(14 - 17.5)
(200 - 249)Normal condition––
Negative
pressure0.5 - 0.6
(5 - 6)
(71.2 - 85.3)The low pressure side
reads a negative pressure,
and the high pressure side
reads an extremely low
pressure.
Presence of frost around
tubing to and from receiver/
dryer and expansion valve.Dust particles or water drop-
lets are either stuck or frozen
inside expansion valve, pre-
venting the refrigerant from
flowing.Clean expansion valve.
Replace it if it cannot be
cleaned.
Replace condenser/dryer.
Evacuate the A/C system and
recharge with fresh refriger-
ant.
Normal :
0.23 - 0.35
(2.3 - 3.5)
(33 - 50)
↑ ↓
↑ ↓↑ ↓ ↑ ↓
Abnormal :
Negative
pressureNormal :
1.4 - 1.75
(14 - 17.5)
(200 - 249)
↑ ↓
↑ ↓↑ ↓ ↑ ↓
Abnormal :
0.7 - 1.0
(7 - 10)
(100 - 142)During A/C operation, the
low pressure side some-
times indicates negative
pressure, and sometimes
normal pressure. Also high
pressure side reading fluc-
tuates between the abnor-
mal and normal pressure.Expansion valve is frozen due
to moisture in the system, and
temporarily shuts off the
refrigeration cycle.Replace expansion valve.
Replace condenser/dryer.
Evacuate A/C system and
recharge with fresh refriger-
ant.
0.05 - 0.15
(0.5 - 1.5)
(4.2 - 21.3)0.7 - 1.0
(7 - 10)
(100 - 142)Both low and high pressure
sides indicate low readings.
Continuous air bubbles are
visible through sight glass.
Output air is slightly cold.Insufficient refrigerant in sys-
tem. (Refrigerant leaking)Using a gas leak detector,
check for leaks and repair as
necessary.
Recharge refrigerant to a
specified amount.
If the pressure reading is
almost 0 when the manifold
gauges are attached, check
for any leaks, repair them,
and evacuate the system.
0.4 - 0.6
(4 - 6)
(56.9 - 85.3)Pressure on low pressure
side is high.
Pressure on high pressure
side is low.
Both pressure becoming
equal right after A/C is
turned OFF.Internal leak in compressor Inspect compressor and
repair or replace as neces-
sary.
0.35 - 0.45
(3.5 - 4.5)
(50 - 64)2.0 - 2.5
(20 - 25)
(285 - 355)High pressure reading on
both low and high pressure
sides.
Air bubbles are not visible
even when engine rpm is
lowered.Overcharged A/C system.
Faulty condenser cooling
operation.
Faulty condenser fan opera-
tion.Adjust refrigerant to specified
amount.
Clean condenser.
Inspect and repair condenser
fan.
High pressure reading on
both low and high pressure
sides.
Low pressure side tubing is
not cold when touched.
Air bubbles are visible
through sight glass.Presence of air in A/C sys-
tem. (Improperly evacuated)Replace condenser dryer.
Inspect quantity of compres-
sor oil and presence of con-
taminants in oil.
Evacuate system and
recharge with fresh refriger-
ant.
0.45 - 0.55
(4.5 - 5.5)
(64 - 78)High pressure reading on
both low and high pressure
sides.
Large amount of frost or
dew on the low pressure
side tubing.Faulty expansion valve.
Refrigerant flow is not regu-
lated properly.Replace expansion valve.
1B-14 AIR CONDITIONING (OPTIONAL)
Wiring Circuit
ACG
LT GRN
PNK
PNK
BLKORN
BLK
YEL/GRNRED/BLKBLK/WHT
BLU/WHTPNK/BLK
PNK/GRN
RED/BLK
WHT/RED
YEL/GRN
YEL/BLU
A/C
RED/BLU
RED/BLU
RED/BLKBLK
BLU/ORN
BLU/WHT
BLU/WHT
PNK
PNK/BLU
BLK
PNK/WHT
YEL/BLK
GRY/WHT
GRN/BLK
BLK/WHT
RED/BLK
YEL/GRN
BLK
BLK
BLK
YEL/BLK
YEL/GRN
YEL/GRNBLU/GRN
BLU/YELBLUBLU/BLK
BLU/BLK
17
21
22 18
16
15
19
2026 25 24 23
14
12
29
3
4
7
33 30
31
32
28
27
1213
10
11
35 349
856
A
1. Front blower motor main relay 10. Compressor relay 19. Battery 28. Solenoid valve relay
2. Front blower motor 11. Compressor 20. Generator 29. Rear blower motor relay
3. Front blower motor resistor 12. Condenser cooling fan motor
relay21. Ignition main fuse 60 A 30. Rear blower motor resistor
4. Front blower motor switch 13. Condenser cooling fan motor 22. Heater/A/C main fuse 60 A 31. Rear blower motor
5. A/C controller 14. Fuse box 23.“IG METER” fuse 20 A 32. Rear blower motor switch
6. ECM (PCM) 15.“A/C” fuse 25 A 24.“REAR DEFG” fuse 25 A 33. Rear A/C main switch
7. Heater mode control switch 16. Ignition switch 25.“REAR BLOW” fuse 20A 34. Rear A/C evaporator temperature con-
troller
8. Dual (refrigerant) pressure switch 17. Main fuse box 26.“FRONT BLOW” fuse 30A 35. Rear A/C evaporator temperature sensor
9. A/C evaporator thermistor
(A/C evaporator temperature sensor)18. Battery main fuse 100 A 27. Solenoid valve [A] : Rear A/C wiring circuit (if equipped)
1B-16 AIR CONDITIONING (OPTIONAL)
SYSTEM CIRCUIT
Terminal arrangement of A/C controller
Terminal arrangement of ECM
A: To “FRONT BLOW” fuse 1. Front blower motor relay 6. Dual (refrigerant) pressure switch 11. Condenser cooling fan motor
B: To “REAR DEFG” fuse 2. Front blower motor 7. A/C thermistor (evaporator temperature sensor) 12. A/C controller
C: To “IG METER” fuse 3. Front blower motor resistor 8. Compressor relay 13. ECM
D: To “A/C” fuse 4. Front blower motor switch 9. Compressor
5. A/C switch 10. Condenser cooling fan motor relay
5V
12V12V
12V5V
12V
5V
AC-A-1
AC-A-7
AC-A-4
AC-B-2
AC-B-1
AC-A-16AC-A-9
AC-A-2 AC-A-13
E61-8
E61-17
E61-22
A
DBBC
1
2
3
4
7 865
1011912
13
12 12
3
45 6 7 8 9 101112131415 16 AC-B
AC-A
87
22 23
34
3565
16 17
25
262
1
8 9
20
212
1
8 9
21
22 1 2 3 4 5 6
9
24 25 26 27 28 29 30 31 32 3310 11
12 13 14 15 16 17 18 19 20 211 2 3 4
7 8 9
10 11 12 13 14 15
18 19 20 21 22 23 243 4 5 6 7
10 11 12 13 14 15 16 17 18 19
22 23 24 25 26
27 283 4 5 6 7
10 11 12 13 14 15 16 19 18 2017
23
24 25 26 27 29 28 30 E61 C51-3 C51-1 C51-2
AIR CONDITIONING (OPTIONAL) 1B-17
A/C CONTROLLER VOLTAGE VALUES TABLE
Terminal Wire CircuitMeasurement
groundNormal value Condition
AC-A-1BLK/
WHTController main
power supplyGround to
engine (Fig B)10 – 14 VIgnition switch ON with engine
stopped
AC-A-2BLK/
YELController main
groundGround to body
(Fig A)–0.4 – 0 V Engine running
AC-A-4 ORNRefrigerant
(dual) pressure
switch inputGround to
engine (Fig B)0 – 1 VRefrigerant pressure within 225
kpa (2.3 kg/cm
2, 32.7 psi) to
2548 kpa (26 kg/cm
2, 370 psi)
with engine running
10 – 14 VRefrigerant pressure below 196
kpa (2.0 kg/cm
2, 28 psi) or above
3140 kpa (32 kg/cm
2, 455 psi)
with engine running
AC-A-7GRN/
BLKA/C switch and/
or defroster
switch inputGround to
engine (Fig B)8 – 14 VBlower fan motor switch or A/C or
defroster switch OFF with engine
running
0 – 1.5 VBlower fan motor switch and A/C
or defroster switch ON with
engine running
AC-A-9GRY/
WHTSignal input from
ECM (A/C ON
permission sig-
nal)Ground to
engine (Fig B)10 – 14 V Approve of A/C ON
0 – 1 V A/C ON forbid
AC-A-13YEL/
BLKSignal output to
ECM (A/C ON
request signal)Ground to
engine (Fig B)0 – 1.5 VBlower fan motor switch and A/C
or defroster switch ON with
engine running at A/C evaporator
temperature sensor temperature
input more than approx. 2.5 °C
(less than 2.5 V (5840 Ω)) and
refrigerant pressure switch is ON
10 – 14 VExcept the above-mentioned with
engine running
AC-A-16 PNKCompressor
magnet clutch
relay outputGround to
engine (Fig B)0 – 1 VBlower fan motor switch and A/C
or defroster switch ON with
engine running at A/C evaporator
temperature sensor temperature
input more than approx. 2.5 °C
(less than 2.5 V (5840 Ω)), refrig-
erant pressure switch ON and
signal input from ECM ON
10 – 14 VExcept the above-mentioned with
engine running
AC-B-1BLU/
YELSensor groundGround to body
(Fig A)–0.4 – 0 V Engine running
1B-18 AIR CONDITIONING (OPTIONAL)
Terminal Wire CircuitMeasurement
groundNormal value Condition
AC-B-2WHT/
BLKA/C evaporator
temperature
sensor (A/C
evaporator ther-
mistor) inputGround to
engine (Fig B)1.8 V
(3520 Ω)A/C evaporator temperature sen-
sor temperature at approx. 15 °C
(59 °F) with engine running
2.51 V
(5.855 Ω)A/C evaporator temperature sen-
sor temperature at approx. 4.5 °C
(34 °F) with engine running
If the temperature is less than
approx. 4.5 °C, in this case com-
pressor and condenser fan
should be stop (come back at
more than approx. 6.1 °C (less
than 5403 Ω, 2.4 V))
E61-8GRY/
WHTSignal output to
A/C controller
(A/C ON permis-
sion signal)Ground to
engine (Fig C)10 – 14 VRequired A/C ON (terminal AC-
A13) at engine running with nor-
mal condition (refer to “INSPEC-
TION OF ECM AND ITS
CIRCUIT” in Section 6E)
0 – 1 VExcept the above-mentioned with
engine running
In this case compressor should
be stop
E61-17YEL/
BLKSignal input from
A/C controller
(A/C ON request
signal)Ground to
engine (Fig C)0 – 1.5 V Require A/C ON
10 – 14 V Turn off the A/C
E61-22YEL/
BLUCondenser cool-
ing fan motor
relay outputGround to
engine (Fig C)0 – 1 VBlower fan motor switch and A/C
or defroster switch ON with
engine running at A/C evaporator
temperature sensor temperature
input more than approx. 2.5 °C
(less than 2.5 V (5840 Ω)), refrig-
erant pressure switch ON and
signal input from ECM ON
Engine coolant temperature sen-
sor more than 113 °C (236 °F)
with engine running
10 – 14 VExcept the above-mentioned with
engine running
AIR CONDITIONING (OPTIONAL) 1B-19
Refrigerant Recovery, Evacuation and Charging
Operation Procedure for Charging A/C with Refrigerant
WARNING:
Your eyes should not be exposed to refrigerant (liquid).
Any liquid Refrigerant-134a escaping by accident shows a temperature as low as approx. –6 °C
(21.2 °F) below freezing point. Should liquid HFC-134a (R-134a) get into your eyes, it may cause a
serious injury. To protect your eyes against such accident, it is necessary to always wear goggles.
Should it occur that HFC-134a (R-134a) strikes your eye(s), consult a doctor immediately.
–Do not use your hand to rub the affected eye(s). Instead, use quantities of fresh cold water to
splash it over the affected area to gradually raise temperature of such area above freezing point.
–Obtain proper treatment as soon as possible from a doctor or eye specialist.
Should the HFC-134a (R-134a) liquid come into contact with your skin, the affected area should be
treated in the same manner as when skin is frostbitten or frozen.
Refrigerant must not be handled near where welding or steam cleaning is performed.
Refrigerant should be kept at a cold and dark place. It should never be stored where a high temper-
ature is anticipated, e.g. where exposed to direct sun light, close to fire or inside vehicle (including
trunk room).
Avoid breathing fumes produced when HFC-134a (R-134a) is burned. Such fumes may be hazardous
to health.
Start evacuating
Charge proper amount of refrigerant
in gas form
Amount of refrigerant
Dual A/C model : 750±50g (1.65±0.11 lb, 26.45±1.76 oz)
Single A/C model : 500±50g (1.1±0.11 lb, 17.64±1.76 oz)
Inspect and repair connections Stop evacuating
Performance test
Check system for pressure tightness
Charge A/C with refrigerant
Check system for refrigerant leaks and
refrigerant charging quantity
20 minutes
Wait 10 minutes
If gauge shows abnormal conditions
AIR CONDITIONING (OPTIONAL) 1B-21
Evacuating
Evacuating procedure
1) Connect high charging hose (1) and low charging hose (2) of
manifold gauge set (3) respectively as follows:
High Charging Hose (1) → High pressure charging valve (4)
on Discharge Hose
Low Charging Hose (2) → Low pressure charging valve (5)
on Suction Pipe
2) Attach center charging hose (6) of manifold gauge set (3) to
vacuum pump (7).
3) Operate vacuum pump (7), and then open discharge-side
valve (9) (Hi) of manifold gauge set (3).
If there is no blockage in the system, there will be an indica-
tion on high pressure gauge (10).
When this occurs, open the other-side valve (8) (Lo) of the
set.
4) Approx. 10 minutes later, low pressure gauge (11) should
show –10 kPa (–1.0 kg/cm
2, –760 mmHg, –14.2 psi) provid-
ing no leakage exists.
5) Evacuation should be carried out for a total of at least 20
minutes.
6) Continue evacuation until low pressure gauge indicates –10
kPa (–1.0 kg/cm
2, –760 mmHg, –14.2 psi), and then close
both valves (8), (9).
7) Stop vacuum pump (7). Disconnect center charging hose (6)
from pump inlet. Now, the system is ready for charging refrig-
erant. CAUTION:
Do not evacuate before recovering refrigerant in system.
NOTE:
Whenever opened (exposed to atmospheric air), air con-
ditioning system must be evacuated by using a vacuum
pump. The A/C system should be attached with a mani-
fold gauge set, and should be evacuated for approx. 20
minutes.
NOTE:
If the system does not show –10 kPa (–1.0 kg/cm
2, –
760 mmHg, –14.2 psi), close both valves, stop vacuum
pump and watch movement of low pressure gauge.
Increase in the gauge reading suggests existence of
leakage. In this case, repair the system before continu-
ing its evacuation.
If the gauge shows a stable reading (suggesting no
leakage), continue evacuation.
3
11
8
2106
7
9
1
4
5
1B-22 AIR CONDITIONING (OPTIONAL)
Checking system for pressure leaks
After completing the evacuation, close manifold gauge high pres-
sure valve (HI) and low-pressure valve (LO) and wait 10 minutes.
Verify that low-pressure gauge reading has not changed.
Charging
CAUTION:
If the gauge reading moves closer to “0”, there is a leak
somewhere. Inspect the tubing connections, make nec-
essary corrections, and evacuate system once again,
making sure that there are no leaks.
CAUTION:
ALWAYS CHARGE THROUGH LOW PRESSURE-SIDE of A/C system at after the initial charging is
performed from the high-pressure side with the engine stopped.
NEVER CHARGE TO HIGH PRESSURE-SIDE of A/C system with engine running.
Do not charge while compressor is hot.
When installing tap valve to refrigerant container to make a hole there through, carefully follow
directions given by manufacturer.
A pressure gauge should always be used before and during charging.
The refrigerant container should be emptied of refrigerant when discarding it.
The refrigerant container should not be heated up to 40 °C (104 °F) or over.
Refrigerant container should not be reversed in direction during charging. Reversing in direction
causes liquid refrigerant to enter compressor, causing troubles, such as compression of liquid
refrigerant and the like.
NOTE:
The air conditioning system contains HFC-134a (R-134a).
Described here is a method to charge the air conditioning system with refrigerant from the refrigerant
service container.
When charging refrigerant recovered by using the refrigerant and recycling equipment (when recy-
cling refrigerant), follow the procedure described in the equipment manufacturer’s instruction manual.