Thermistor ac SUZUKI GRAND VITARA 2003 2.G Service Workshop Manual

YH4
GRAND
VITARA
1B-2 AIR CONDITIONING (OPTIONAL)
Condenser Dryer (Receiver / Dryer) 1B-36. . . . . .
Air Filter Element 1B-37. . . . . . . . . . . . . . . . . . . . .
Cooling Unit (Evaporator) 1B-39. . . . . . . . . . . . . .
Expansion Valve 1B-42. . . . . . . . . . . . . . . . . . . . .
A / C Evaporator Thermistor (Evaporator
Temperature Sensor) 1B-43. . . . . . . . . . . . . . . .
Refrigerant Pipes and Hoses 1B-44. . . . . . . . . . .
A / C Switch 1B-45. . . . . . . . . . . . . . . . . . . . . . . . . .
A / C Controller 1B-46. . . . . . . . . . . . . . . . . . . . . . . .
Dual Pressure Switch 1B-47. . . . . . . . . . . . . . . . . A / C Compressor Relay and A / C
Condenser Cooling Fan Relay 1B-48. . . . . . . .
Compressor Assembly 1B-49. . . . . . . . . . . . . . . .
Magnet Clutch Assembly
(For Denso Compressor) 1B-53. . . . . . . . . . .
Magnet Clutch Assembly
(For Seiko Seiki Compressor) 1B-56. . . . . . .
Lip Type Seal (For Seiko Seiki) 1B-59. . . . . . .
REQUIRED SERVICE MATERIAL1B-61 . . . . . . . .
SPECIAL TOOLS1B-61 . . . . . . . . . . . . . . . . . . . . . .

YH4
GRAND
VITARA
1B-6 AIR CONDITIONING (OPTIONAL)
DIAGNOSIS
GENERAL
ConditionPossible CauseCorrection
Cool air won't come out
(A / C system won't
operative)
No refrigerant

Fuse blown

A / C switch faulty

Blower motor switch faulty

A / C thermistor faulty

Dual pressure switch faulty

Wiring or grounding faulty

A / C ON permission signal in ECM
faulty

A / C controller and its circuit faultyRecover, evacuation and charging.
Check ªIG METERº fuse, ªREAR DEFGº
fuse, and ªA / C FUSEº and check for
short circuit to ground.
Check A / C switch.
Check blower motor switch.
Check A / C evaporator thermistor.
Check dual pressure switch.
Repair as necessary.
Check ON permission signal.
Check A / C controller and its circuit.
Cool air won't come out
(A / C compressor won't
operative)
Magnet clutch faulty

Compressor relay faulty

Compressor thermal switch faulty
(if equipped)

Drive belt loose or broken

Compressor faulty

A / C ON permission signal in ECM
faulty

A / C controller faultyCheck magnet clutch.
Check compressor thermal switch.
Check compressor relay.
Adjust or replace drive belt.
Check compressor.
Check ON permission signal.
Check A / C controller.
Cool air won't come out
(A / C condenser cooling
fan motor won't
operative)
Condenser cooling fan relay faulty

Wiring or grounding faulty

ªA / C condenser cooling fan relayº
signal in ECM faulty

Condenser cooling fan motor faultyCheck condenser cooling fan relay.
Repair as necessary.
Check A / C condenser cooling fan relay
signal.
Check condenser cooling fan motor.
Cool air won't come out
(Blower motor won't
operative)
Fuse blown

Blower motor relay faulty

Blower motor resistor faulty

Blower motor switch faulty

Wiring or grounding faulty

Blower motor faultyCheck ªHEATER FUSEº, ªREAR DEFGº
fuse and check for short circuit to
ground.
Check blower motor relay.
Check blower motor resistor.
Check blower motor switch.
Repair as necessary.
Check blower motor.
Cool air won't come out
or insufficient cooling
(A / C system normal
operative)
Insufficient or excessive charge of
refrigerant

Refrigerant leak in system

Condenser clogged

A / C evaporator clogged or frosted

A / C thermistor faulty

A / C controller faulty

Expansion valve faulty

Drive belt slipping

Magnetic clutch faultyCheck charge of refrigerant.
Check system for leaks.
Check condenser.
Check A / C evaporator.
Check A / C thermistor.
Check A / C controller.
Check expansion valve.
Check or replace drive belt.
Check magnetic clutch.

YH4
GRAND
VITARA
AIR CONDITIONING (OPTIONAL) 1B-7
ConditionPossible CauseCorrection
Cool air does not come
out or insufficient
cooling (A / C system
normal operative)
Compressor faulty

Air in A / C system

Air leaking from cooling unit or air
duct

Heater and ventilation system faulty

Blower motor faulty

Excessive compressor oil existing in
A / C systemCheck compressor.
Replace condenser dryer, and
evacuation and charging.
Repair as necessary.
Check blower unit.
Check heater control lever assembly.
Check heater assembly.
Check blower motor.
Pull out compressor oil in A / C system
circuit, and replace compressor.
Cool air does not comes
out only intermittently
Wiring connection faulty

Expansion valve faulty

Excessive moisture in A / C system

A / C controller faulty

Magnetic clutch faulty

Excessive charge of refrigerantRepair as necessary.
Check expansion valve.
Replace condenser dryer, and
evacuation and charging.
Check A / C controller.
Check magnetic clutch.
Check charge of refrigerant.
Cool air comes out only
at high speeds
Condenser clogged

Insufficient charge of refrigerant

Air in A / C system

Drive belt slipping

Compressor faultyCheck condenser.
Check charge of refrigerant.
Replace condenser dryer, and
evacuation and charging.
Adjust or replace drive belt.
Check compressor.
Cool air does not comes
out only at high speeds
Excessive charge of refrigerant

A / C evaporator frostedCheck charge refrigerant.
Check A / C evaporator.
Check A / C thermistor.
Insufficient velocity of
cooled air
A / C evaporator clogged or frosted

Air leaking from cooling unit or air
duct

Blower motor faulty

Wiring or grounding faultyCheck A / C evaporator.
Repair as necessary.
Check blower motor.
Repair as necessary.

YH4
GRAND
VITARA
SYSTEM CIRCUIT
A. To heater fuse
B. To rear defogger fuse
C. To ignition / meter fuse
D. To A / C fuse
E. Only LH vehicle1. Blower motor relay
2. Blower motor
3. Blower motor switch
4. A / C switch
5. Deflloster position switch
6. Deflloster / foot position switch7. Dual pressure (refrigerant
pressure) switch
8. A / C thermistor (evaporator
temperature sensor)
9. Compressor relay
10. Compressor11. Condenser fan motor relay
12. Condenser fan motor
13. A / C controller
14. ECM
15. Compressor thermal switch
(only IWATA production vehicle)
TERMINAL ARRANGEMENT OF A / C CONTROLLER
TERMINAL ARRANGEMENT OF ECM FOR G16, J20 ENGINE
TERMINAL ARRANGEMENT OF ECM FOR H25 ENGINE
H25 engine
E61-27
G16, J20
engines
E61-8
H25 engine
E61-28
G16, J20
engines
E61-17
1919
19H25 engine
E61-5
G16, J20
engines
E61-22
AIR CONDITIONING (OPTIONAL) 1B-19

YH4
GRAND
VITARA
1B-20 AIR CONDITIONING (OPTIONAL)
A / C CONTROLLER VOLTAGE VALUES TABLE
TerminalWireCircuitMeasurement
groundNormal valueCondition
AC1-1B/WController main
power supplyGround to
engine (Fig. B)10 ± 14 voltsIgnition switch ON with engine
stopped
AC1-2B/YController main
groundGround to body
(Fig. A)± 0.4 ± 0 voltEngine running
AC1 4Or
Refrigerant
p
ressure switchGround to
0 ± 1 volt
Refrigerant pressure within 225 kPa
(2.3 kg / cm
2, 32.7 psi) to 2548 kPa
(26 kg / cm
2, 370 psi) with engine
running
AC1-4Orpressure switch
inputengine (Fig. B)
10 ± 14 volts
Refrigerant pressure below
196 kPa (2.0 kg / cm
2, 28 psi) or
above 3140 kPa (32 kg / cm
2, 455 psi)
with engine running
AC1 7G/B
A / C switch input
and / or defroster
Ground to
8 ± 14 volts
Blower fan motor switch and A / C or
defroster position switch (see NOTE)
ON with engine running
AC1-7G/Bposition switch
input (see NOTE)engine (Fig. B)
0 ± 1.5 volts
Blower fan motor switch or A / C or
defroster position switch (see NOTE)
OFF with engine running
AC1 9Gr/W
Signal input from
ECM (A / C ON
Ground to10 ± 14 voltsApprove of A / C ON
AC1-9Gr/W(
permission
signal)engine (Fig. B)0 ± 1 voltA / C ON forbid
AC1-13Y/B
Signal output to
ECM (A / C ON
request signal)Ground to engine
(Fig. B)0 ± 1.5 volts
Blower fan motor switch and A / C or
defroster position switch (see NOTE)
ON with engine running at evaporator
thermistor temperature input more
than approx. 2.5
C (less than 2.5 V
(5840
)) and refrigerant pressure
switch is ON
10 ± 14 voltsExcept the above-mentioned with
engine running
AC1-16P
Compressor
magnet clutch
relay outputGround to engine
(Fig. B)0 ± 1 volt
Blower fan motor switch and A / C or
defroster position switch ON with
engine running at evaporator
thermistor temperature input more
than approx. 2.5
C (less than 2.5 V
(5840
)), refrigerant pressure
switch ON and signal input from ECM
ON
10 ± 14 voltsExcept the above-mentioned with
engine running

YH4
GRAND
VITARA
AIR CONDITIONING (OPTIONAL) 1B-21
TerminalWireCircuitMeasurement
groundNormal valueCondition
AC2-1L/YSensor groundGround to body
(Fig. A)± 0.4 ± 0 voltEngine running
1.5 volts
(3150
)Evaporator thermistor temperature at
approx. 15C (59F) with engine
running
AC2-2W/B
Evaporator
thermistor
temperature
(evaporator temp.
sensor) input
Ground to engine
(Fig. B)
2.62 volts
(6.311
)
Evaporator thermistor temperature at
approx. 1C (34F) with engine
running
* If the temperature is less than
approx. 1C, in this case
compressor and condenser fan
should be stop (come back at more
than approx. 2.5C (less than
5840
, 2.5 V))
H25
engine
E61-27 /
G16 J20Gr/W
Signal output to
A / C controller
(A / C ON
Ground to engine
(Fig C)
10 ± 14 volts
Required A / C ON (terminal AC-A13)
at engine running with normal
condition (refer to ªINSPECTION OF
ECM AND ITS CIRCUITº in Section
6E)
G16, J20
engines
E61-8
(
permission
signal)(Fig. C)
0 ± 1 volt
Except the above-mentioned with
engine running
In this case compressor should be
stop
H25
engine
E61-28 /
Y/B
Signal input from
A / C controller
Ground to engine
0 ± 1.5 voltsRequire A / C ON
G16, J20
engines
E61-17Y/B(A / C ON request
signal)
g
(Fig. C)
10 ± 14 voltsTurn off the A / C
H25
engine
E61-5 /
G16, J20
engines
E61-22
Y/L
A / C condenser
cooling fan relay
outputGround to engine
(Fig. C)0 ± 1 volt

Blower fan motor switch and A / C or
defroster position switch (see
NOTE) ON with engine running at
evaporator thermistor temperature
input more than approx. 2.5C (less
than 2.5 V (5840
)), refrigerant
pressure switch ON and signal
input from ECM ON

Engine coolant temperature sensor
more than 113C (236F) with
engine running
10 ± 14 voltsExcept the above-mentioned with
engine running
NOTE:
Defroster position switch circuit is equipped with LH vehicle only.

YH4
GRAND
VITARA
AIR CONDITIONING (OPTIONAL) 1B-39
COOLING UNIT (EVAPORATOR)
REMOVAL
1) Disconnect negative (±) cable at battery.
2) Disable air bag system. Refer to ªDisabling Air Bag Systemº in
Section 10B.
3) 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 added to the system.
4) For G16 and J20 engine
Disconnect suction pipe (1), and liquid pipe (2) from evaporator
(cooling unit).
CAUTION:
As soon as above hose and pipe are disconnected, cap
opened fittings so that moisture and dust may not enter
cooling unit.
5) Remove blower motor unit. Refer to Section 1A ªHEATER AND
VENTILATIONº.
6) Disconnect thermistor wire coupler.
7) Remove cooling unit (evaporator).
DISASSEMBLY (FOR CAMI PRODUCTION VEHICLE)
1) Remove filter (2) from cooling unit (3) assembly by removing fil-
ter cover (1).
2) Remove screws (1) to separate evaporator upper and lower
cases from each other.

YH4
GRAND
VITARA
1
1B-40 AIR CONDITIONING (OPTIONAL)
3) Remove upper case (1) and remove evaporator (2) from lower
case (3).
4) Remove following components from evaporator.

Expansion valve (5)

Thermistor (evaporator temperature sensor) (4)
DISASSEMBLY (FOR IWATA PRODUCTION VEHICLE)
1) Remove filter (2) from cooling unit (3) assembly by removing fil-
ter cover (1).
2) Detach clamps (1) to separate evaporator upper and lower
cases from each other.
3) Remove upper case (1) and remove evaporator (2) from lower
case (3).
4) Remove following components from evaporator.

Expansion valve (5)

Thermistor (evaporator temperature sensor) (4)

YH4
GRAND
VITARA
AIR CONDITIONING (OPTIONAL) 1B-41
INSPECTION
1) Check evaporator fins for blockage. If found clogged, use com-
pressed air to clean the fins.
CAUTION:
Do not use water for cleaning of evaporator.
Be careful not to damage evaporator fins. If evaporator
fin is bent, straighten it by using a screwdriver or pair of
pliers. If any leakage is found from fitting or tube, repair
or replace evaporator.
2) Check inlet and outlet fittings for crack or scratch. Repair them
as required.
REASSEMBLY and INSTALLATION
1) Reverse removal and disassembly sequence to install cooling
unit, noting the following points.

Install uniformly the evaporator packing to dash panel hole for
expansion valve.

Adjust fresh air control cable, refer to ªHEATER CONTROL
LEVER ASSEMBLYº in Section 1A.
2) Enable air bag system. Refer to ªEnabling Air Bag Systemº in
Section 10B.
3) Evacuate and charge system. Refer to ªEVACUATINGº and
ªCHARGINGº in this section.
NOTE:
When the thermistor removed, it should be reinstalled in
original position.
If cooling unit or evaporator is replaced, pour 25 cc of refrig-
erating oil to compressor suction-side.

YH4
GRAND
VITARA
1. Evaporator thermistorTemperature
Resistance ( )


AIR CONDITIONING (OPTIONAL) 1B-43
A / C EVAPORATOR THERMISTOR
(EVAPORATOR TEMPERATURE SENSOR)
A thermistor is a temperature sensor to sense the temperature of
air discharged from evaporator. The electrical characteristic is
shown in the figure.
When temperature is lower than preset temperature, amplifier
makes magnet clutch turn off to prevent evaporator from frosting.
INSPECTION
Check resistance between A / C evaporator thermistor (1) termi-
nals.
If check results are as not specified, replace thermistor.
Sensor Temperature
Resistance
0
C, 32
F7.0 ± 7.7 k

25
C, 77
F2.1 ± 2.4 k

REMOVAL
Refer to ªCOOLING UNIT (EVAPORATOR)º in this section.
INSTALLATION
1) Reverse removal sequence to install thermistor.
2) Enable air bag system. Refer to ªENABLING AIR BAG SYS-
TEMº in Section 10B.
3) Evacuate and charge system. Refer to ªEVACUATINGº and
ªCHARGINGº in this section.