Page 37 of 656

1B-12 AIR CONDITIONING (OPTIONAL)
Performance diagnosis table
HIGH PRESSURE GAUGE
LOW PRESSURE GAUGE
THERMOMETER AT CENTER DUCT
Condition Possible Cause Correction
Pressure high
(“A” area of high side
graph)Refrigerant overcharged Recharge.
Expansion valve frozen or clogged Check expansion valve.
Clogged refrigerant passage of high side Clean or replace.
Condenser cooling fan malfunction (Insufficient cooling
of condenser)Check condenser cooling fan.
Dirty or bent condenser fins (Insufficient cooling of con-
denser)Clean or repair.
Compressor malfunction (Insufficient oil etc.) Check compressor.
Engine overheat Check engine cooling system.
Pressure low
(“B” area of high side
graph)Insufficient refrigerant (Insufficient charge or leakage) Check for leakage, repair if necessary
and recharge.
Expansion valve malfunction (valve opens too wide) Check expansion valve.
Compressor malfunction (Insufficient compression) Check compressor.
Condition Possible Cause Correction
Pressure high
(“C” area of low side
graph)Expansion valve malfunction (valve opens too wide) Check expansion valve.
Compressor malfunction (Insufficient compression) Check compressor.
Pressure low
(“D” area of low side
graph)Insufficient refrigerant (Insufficient charge or leakage) Check for leakage, repair if necessary
and recharge.
Expansion valve malfunction (valve opens too narrow) Check expansion valve.
Clogged refrigerant passage (crashed pipe) Repair or replace.
Condition Possible Cause Correction
Outlet air temperature at
center duct is high
(Crossing point is in area
“E”)Insufficient or excessive charge of refrigerant Check refrigerant pressure.
Dirty or bent A/C evaporator fins Clean or repair.
Air leakage from cooling (heater) unit or air duct Repair or replace.
Malfunctioning, switch over function of damper in cool-
ing (heater) unitRepair or replace.
Compressor malfunction Check compressor.
Outlet air temperature at
center duct is low
(Crossing point is in area
“F”)Insufficient air volume from center duct (Heater blower
malfunction)Check blower motor and fan.
Compressor malfunction Check compressor.
NOTE:
If ambient temperature is within 30 - 35 °C (85 - 95 °F), it is possible to do using “DETAIL DIAGNOSIS
TABLE” in this section for detail diagnosis.
Page 40 of 656
AIR CONDITIONING (OPTIONAL) 1B-15
Inspection of A/C Controller and Its Circuits
A/C Controller (1) and its circuits can be checked at A/C controller
wiring couplers by measuring voltage.
Voltage check
1) Remove A/C controller (1) from vehicle referring to “A/C
CONTROLLER” in this section.
2) Remove ECM (2) from vehicle.
3) Connect A/C controller couplers to A/C controller and con-
nect ECM couplers to ECM.
4) Check each terminal voltage with couplers connected by
referring to “A/C CONTROLLER VOLTAGE VALUES TABLE”. CAUTION:
A/C controller and ECM cannot be checked by itself.
It is strictly prohibited to connect voltmeter or ohmmeter
to A/C controller and ECM with couplers disconnected
from it.
3. Terminal AC-A-2
4. Terminal C51-3-6
NOTE:
For “Fig. A”, “Fig. B”, “Fig. C” in the figure, refer to “A/C
CONTROLLER VOLTAGE VALUES TABLE”.
Page 43 of 656

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
Page 50 of 656

AIR CONDITIONING (OPTIONAL) 1B-25
On-Vehicle Service
Precaution
When servicing air conditioning system, the following rules must be observed.
Piping
When connecting hoses and pipes, apply a few drops of compressor oil (refrigerant oil) to seats of coupling
nuts and O-ring. WARNING:
Should refrigerant HFC-134a (R-134a) strike your eye(s), consult a doctor immediately.
DO NOT USE YOUR HAND TO RUB AFFECTED EYE(S).
Instead, use quantities of fresh cold water to splash it over affected area to thus gradually raise its
temperature above the freezing point.
Obtain proper treatment as soon as possible from a doctor or eye specialist.
Should liquid refrigerant HFC-134a (R-134a) get on your skin, such affected part should be treated
in the same manner as when skin is frostbitten or frozen.
CAUTION:
None of refrigerant, compressor oil and component parts is interchangeable between two types of
A/C: one using CFC-12 (R-12) and the other using HFC-134a (R-134a).
(For identification between these two types, refer to “REFRIGERANT TYPE” in this section.
When replenishing or changing refrigerant and compressor oil and when replacing parts, make sure
that the material or the part to be used is appropriate to the A/C installed in the vehicle being serviced.
Use of incorrect one will result in leakage of refrigerant, damage in parts or other faulty condition.
NOTE:
Single A/C model is the same as SQ625 (H25 engine) model. Refer to the same section of the Service
Manual mentioned in FOREWORD of this manual.
[A]: Dual A/C model 1. Suction hose 4. Condenser outlet pipe 7. Front suction pipe
Apply compressor oil (refrigerant oil) to O-ring. 2. Discharge hose 5. Expansion valve 8. Rear liquid pipe
3. Front liquid pipe 6. Dual (refrigerant) pressure switch 9. Rear suction pipe
1
6 43 75
9
8
2 [A]
Page 54 of 656

AIR CONDITIONING (OPTIONAL) 1B-29
4) Loosen floor suction pipe and floor liquid pipe mounting bolt
(1).
5) Remove rear A/C No.1 duct (1).
6) Disconnect rear A/C unit wire couplers (2).
7) Remove rear A/C unit mounting bolts (3), and then remove
rear A/C unit (4).
INSPECTION
Check the following.
Clog of rear A/C evaporator fins.
If any clogs are found, rear A/C evaporator fins should be
washed with water, and should be dried with compressed air.
Rear A/C evaporator fins for leakage and breakage.
If any defects are found, repair or replace rear A/C evapora-
tor.
INSTALLATION
Reverse removal procedure to install rear A/C unit noting the fol-
lowing points.
Evacuate and charge system. Refer to “RECOVERY” and
“EVACUATING” in this section.
When the rear A/C evaporator thermistor (temperature sen-
sor) removed, it should be reinstalled in original position.
If rear A/C unit or rear A/C evaporator is replaced, pour 25
cm
3 (25 cc) of refrigerating oil to compressor suction-side.
Rear Expansion Valve
INSPECTION
Refer to “PERFORMANCE DIAGNOSIS” in this section.
2. Muffler
1
2
NOTE:
Cap open fitting immediately to keep moisture out of sys-
tem.
23
1
4
Page 55 of 656
1B-30 AIR CONDITIONING (OPTIONAL)
REMOVAL
1) Remove rear A/C unit referring to “REAR A/C UNIT” in this
section.
2) Disconnect solenoid valve connector (1).
3) Loosen solenoid valve bracket mounting screws (2).
4) Remove rear liquid pipe and rear suction pipe bolt (1), and
then disconnect rear liquid pipe (2) and rear suction pipe (3)
with solenoid valve and its bracket from rear expansion valve
(4).
5) Remove rear expansion valve (4) from rear A/C unit (5).
INSTALLATION
Reverse removal procedure to install rear expansion valve.
Rear A/C Evaporator Temperature Controller
REMOVAL
1) Remove rear A/C unit referring to “REAR A/C UNIT” in this
section.
2) Disconnect rear A/C evaporator temperature controller con-
nector (1).
3) Remove rear A/C evaporator temperature controller (2) from
rear A/C unit.
21
NOTE:
Cap open fitting immediately to keep moisture out of sys-
tem.
4
1
2
3
5
1 2
Page 56 of 656

AIR CONDITIONING (OPTIONAL) 1B-31
INSPECTION
1) Connect battery positive (+) cable to terminal “b” and battery
negative (–) cable to terminal “c” as shown.
2) Using ohmmeter, check continuity between terminal “a” and
terminal “b” at specified temperature as shown.
Rear A/C evaporator temperature controller specification :
“A” : Approximately 3.5 °C (38.3 °F)
“B” : Approximately 5.0 °C (41 °F)
INSTALLATION
Reverse removal procedure to install rear A/C evaporator temper-
ature controller noting the following instruction.
When the rear A/C evaporator thermistor (temperature sen-
sor) removed, it should be reinstalled in original position.
Refrigerant Pipes and Hoses
INSPECTION
Use a leak tester to check hoses and pipes for any gas leakage.
Check each hose or pipe clamp for tightness. Retighten or replace loose clamp as required, if any.
REMOVAL
1) Recover refrigerant by using recovery and recycling equipment. Be sure to follow the instruction manual for
the equipment.
The amount of compressor oil removed must be measured and the same amount must be added to the sys-
tem when reinstalling.
2) Replace defective hose or pipe.
INSTALLATION
Reverse removal procedure to install refrigerant line noting the following instruction.
Evacuate and charge system. Refer to “EVACUATING” and “CHARGING” in this section.
CAUTION:
As soon as the above hose or pipe is disconnected, cap its opened fitting to prevent moisture and
dust from entering.
NOTE:
Remove EVAP canister and fuel tank cover, if necessary
Page 57 of 656

1B-32 AIR CONDITIONING (OPTIONAL)
Solenoid Valve
REMOVAL
1) Remove rear A/C unit referring to “REAR A/C UNIT” in this
section.
2) Disconnect solenoid valve connector (1).
3) Loosen solenoid valve flared nuts (2).
4) Remove solenoid valve bracket mounting screws (3), and
then remove rear liquid pipe (4) and rear suction pipe (5)
from rear expansion valve.
5) Remove rear liquid pipe (4), rear suction pipe (5) and sole-
noid valve bracket (6) from solenoid valve (7).
INSPECTION
1) Connect special tool to solenoid valve (1).
Special tool
(A) : 09917-47910
2) Check that solenoid valve is closed when vacuum is applied
to solenoid valve.
If solenoid valve is opened, replace solenoid valve.
3) Check that solenoid valve (1) is opened when connect bat-
tery to solenoid valve as shown in figure.
INSTALLATION
Reverse removal procedure to install solenoid valve.NOTE:
Cap open fitting immediately to keep moisture out of sys-
tem.
2
5
367 1 3 4
1(A)
NOTE:
Solenoid valve terminal is no polarity.
1