2008 SUZUKI SWIFT 100

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Automatic Type
Precautions
A/C System CautionS7RS0B7220001
Refer to “A/C System Caution”.
Precautions in Diagnosing TroubleS7RS0B7220002
• Do not disconnect couplers from HVAC control module, battery cable from battery, HVAC control module ground
wire harness from body or main fuse before confirming diagnostic information (diagnostic trouble code) stored in
HVAC control module memory.
• Diagnostic information (diagnostic trouble code) stored in HVAC control module can be checked by display of HVAC
control module. Also, it can be checked by using SU ZUKI scan tool. Before checking diagnostic information
(diagnostic trouble code), read this manual and operator's manual for SUZUKI scan tool to know how to read
diagnostic information (diagnostic trouble code).
• When trouble is diagnosed using diagnostic information (diagnostic trouble code) on display of HVAC control
module, keep in your mind that each diagnostic inform ation (diagnostic trouble code) has priority, and only
diagnostic information (diagnostic troub le code) which has the highest priority is indicated. Therefore, after
troubleshooting the malfunction, make sure if there exists any other diagnostic information (diagnostic trouble
code).
• Be sure to read “Precautions for Electrical Circuit Service in Section 00” before inspection.
Precautions on Servicing A/C SystemS7RS0B7220003
Refer to “Precautions on Servicing A/C System”.
General Description
Auto A/C System DescriptionS7RS0B7221001
The automatic type air conditioning system (auto A/C) is pr ovided with the function to automatically control the inside
air temperature, fan speed, air flow outl et direction and air intake position by HVAC control module in addition to
functions of the manual type air conditioning system (manua l A/C). Once the inside air temperature is set using the
temperature selector, HVAC control module automatically controls the inside air temperature at the constant level at all
times based on the inside air temperature, outside ai r temperature, amount of sunlight and engine coolant
temperature detected respectively by the inside air te mperature sensor, outside air temperature sensor, sunload
sensor and ECT sensor. At this time, “FULL AUTO A/ C” appears on the display of HVAC control module.
With the air intake selector pushed in the above state, it is possible to select any position of the air intake actuator.
Then, “FULL AUTO A/C” on the display changes to “AUTO A/C”.

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Auto A/C Electronic Control Input / Output Table
HVAC Control Module Operation DescriptionS7RS0B7221002
Temperature Control
HVAC control module calculates the target temperature
control door position based on signals from the
temperature selector, inside air temperature sensor,
outside air temperature sensor and sunload sensor and
controls the temperature control actuator so that the
current position of the temperature control door matches
its target position.
Fan Speed Control
HVAC control module calculates the target blower fan
speed based on signals from the temperature selector,
inside air temperature sensor, outside air temperature
sensor and sunload sensor, compares it with the current
blower fan speed inputted from the blower motor
controller to control the current blower fan speed to the
target level.
Air Flow Outlet Control
HVAC control module calculates the target temperature
control door position based on signals from the
temperature selector, inside air temperature sensor,
outside air temperature sensor and sunload sensor.
Using thus obtained target temperature control door
position, it further calculates the target air flow control
door position and controls the ai r flow control actuator so
that the current air flow c ontrol door position becomes
the target position. Air Intake Position Control
HVAC control module determines the position of the air
intake control door based on signals from the
temperature selector, inside air temperature sensor,
outside air temperature sensor and sunload sensor and
selects any of the following positions by controlling the
position of the air intake control door.
• FRESH position (FRE)
• RECIRCULATION position (REC)
• MIX position (MIX)
Refrigerant Type IdentificationS7RS0B7221003
Refer to “Refrigerant Type Identification”.
Sub-Cool A/C System DescriptionS7RS0B7221005
Refer to “Sub-Cool A/C System Description”.
A/C Operation DescriptionS7RS0B7221006
Refer to “A/C Operation Description”.
Sunload sensor
Outside air temperature sensor Evaporator temperature sensor
A/C refrigerant pressure sensor
Temperature selector
MODE (air flow) selector
Blower speed selector
Air intake selector
AUTO switch
A/C switch
Compressor
Blower motor controller
Temperature control actuator
Air flow control actuator
Air intake control actuator
BCM
ECM
Data link connector
HVAC control module
CPU
ECT sensor
Inside air temperature sensor
VSS
*
I5RS0C722002-02
*: CAN communication

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On-Board Diagnostic System DescriptionS7RS0B7221007
NOTE
The diagnostic information as diagnostic
trouble code (DTC) can be known by using
SUZUKI scan tool. For further details, refer to
“DTC Check”.

HVAC control module detect s malfunctions, which may
occur in the following area.
• Outside air temperature sensor
• Inside air temperature sensor
• Evaporator temperature sensor
• Sunload sensor
• ECT sensor
• Temperature control actuator of HVAC unit
• Air flow control actuator of HVAC unit
• A/C refrigerant pressure sensor • HVAC control module
• VSS
• Serial Communication line
• CAN communication line
When HVAC control module detects malfunction, the
“AUTO” indicator lamp (1) flashes to warn and the
diagnostic trouble code (DTC) is stored in the memory of
the module. When diagnosing trouble, the DTC can be
checked according to “DTC Check”.
Schematic and Routing Diagram
Major Components of A/C SystemS7RS0B7222001
Refer to “Major Components of A/C System”.
1
I5RS0A722003-01

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Abnormal Noise Symptom Diagnosis of A/C
System
S7RS0B7224002
Refer to “Abnormal Noise Symptom Diagnosis of A/C
System”.
DTC CheckS7RS0B7224003
Using SUZUKI Scan Tool1) Turn ignition switch to OFF position.
2) Connect SUZUKI scan tool to data link connector (DLC) (1) located on underside of instrument panel
at driver’s seat side.
Special tool
(A): SUZUKI scan tool 3) Light over sunload sensor vertically with an
incandescent lamp of approximately 100 W apart
from about 100 mm (3.94 in.).
NOTE
If sunload sensor is not lighted over with an
incandescent lamp, DTC B1504 is detected
even though there is not any malfunction.

4) Turn ignition switch to ON position.
5) Read DTC displayed on SUZUKI scan tool.
NOTE
To know how to use SUZUKI scan tool, refer
to operator’s manual for SUZUKI scan tool.

6) After completing the check, turn ignition switch to
OFF position and disconnect SUZUKI scan tool from
data link connector (DLC).
Cool air does not come
out only at high speed
Excessive amount of refrigerant
Check the amount of refrigerant.
A/C evaporator frosted Check A/C evaporator and evaporator
temperature sensor referring to “Evaporator
Inspection” and “Evaporator Thermistor
(Evaporator Temperature Sensor) Inspection”.
Insufficient air flow of
cooled air A/C evaporator clogged or frosted
Check A/C evaporator and evaporator
temperature sensor referring to “Evaporator
Inspection” and “Evaporator Thermistor
(Evaporator Temperature Sensor) Inspection”.
Air leaking from HVAC unit or air duct Repair as necessary.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Wiring or grounding faulty Repair as necessary.
Condition Possible cause Correction / Reference Item
(A)
1
I5RS0A722005-01

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Not Using SUZUKI Scan Tool
Current DTC mode1) Light over sunload sensor vertically with an incandescent lamp of approximately 100 W apart
from about 100 mm (3.94 in.).
NOTE
If sunload sensor is not lighted over with an
incandescent lamp, DTC B1504 is detected
as current DTC even though there is not any
malfunction.

2) Start engine.
3) Wait for 20 seconds or more after engine started and set temperature selector to 25 °C (77 °F).
4) Push AUTO switch (1) and defroster switch (2) at the same time.
5) Check DTC (3).
NOTE
• DTC flashes for 15 seconds. After that, the normal display is rest ored. To have DTC
displayed again, repeat the procedure from
Step 4.
• When more than two DTCs are detected, only DTC having the highest priority is
indicated. Therefore, after troubleshooting
the malfunction, DTC check has to be
performed again to see if any other DTC(s)
is detected.

History DTC mode
1) Turn ignition switch to ON position.
2) Set temperature selector to 25 °C (77 °F).
3) Push AUTO switch (1) and MODE (air flow) selector
(2) at the same time.
4) Check DTC (4).
NOTE
Each DTC item is displayed (lights up) for 4
seconds.
When HVAC control module detects 2 or
more DTC items, each one is displayed once
starting from the one of higher priority order.
After all DTC items being detected have been
displayed, “Ed” (3) appears on display of
HVAC control module and normal display is
restored. “Ed” means that all DTC items have
been displayed.

DTC ClearanceS7RS0B7224004
NOTE
Only history DTC(s) can be cleared. Current
DTC(s) can not be cleared unless the
problem(s) is fixed.

Using SUZUKI Scan tool
1) Turn ignition switch to OFF position.
2) Connect SUZUKI scan tool to data link connector (DLC) (1) located on underside of instrument panel
at driver’s seat side.
Special tool
(A): SUZUKI scan tool1
2
3
I5RS0A722006-02
1
2 34
I5RS0A722007-02
(A)
1
I5RS0A722005-01

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3) Light over sunload sensor vertically with an incandescent lamp approximately 100 W apart from
about 100 mm (3.94 in.).
NOTE
If sunload sensor is not lighted over with an
incandescent lamp, DTC B1504 is detected
as current DTC even though there is not any
malfunction.

4) Turn ignition switch to ON position.
5) Erase DTC according to instructions displayed on SUZUKI scan tool.
NOTE
To know how to use SUZUKI scan tool, refer
to operator’s manual for SUZUKI scan tool.

6) After completing the clearance, turn ignition switch to OFF position, and then di sconnect SUZUKI scan
tool from DLC.
Not Using SUZUKI Scan Tool 1) Turn ignition switch to ON position.
2) Set temperature selector to 25 °C (77 °F). 3) Push AUTO switch (1) and
MODE (air flow) selector
(2) at the same time to have history DTC displayed.
4) Push MODE (air flow) selector (2) and OFF switch (3) at the same time while history DTC is displayed.
5) Check that “CL” (4) appears on display. “CL” means that DTC has been cleared.
DTC TableS7RS0B7224005
CAUTION!
Be sure to perform “Air Conditioning Sy stem Check” before starting diagnosis.

1
2
3
2
4
I5RS0A722008-01
DTC No.
(displayed on
SUZUKI
scan tool) DTC
(indicated on
display of HVAC
control
module) Priority of
display
(current DTC) Priority
of
display
(history DTC) Diagnosis
“AUTO”
indicator lamp
) B1502 21 1 1 Inside air temperature sensor and/or its
circuit malfunction Open
Flashed
22 2 2 Short
) B1503 31 3 3 Evaporator temperature sensor and/or its
circuit malfunction Open
Flashed
32 4 4 Short
) B1504 41 21 — Sunload sensor and/or its circuit
malfunction Open —
42 5 5 Short Flashed
) B1511 61 6 6 Temperature control actuator (position
sensor) and/or its circuit malfunction Open
Flashed
62 7 7 Short
) B1512 71 8 8 Air flow control actuator (position sensor)
and/or its circuit malfunction Open
Flashed
72 9 9 Short
) B1513 63 10 10 Temperature control actuator and/or its circuit malfunction Flashed
) B1514 73 11 11 Air flow control actuator and/or its circuit malfunction Flashed
) B1541 E1 12 — HVAC control module back-up power supply malfunction —
) B1546 d5 22 — A/C refrigerant pressure malfunction —
) B1551 91 13 12
Serial communication circuit malfunction Open
Flashed
92 14 13 Short
) B1552 94 15 14 Serial communication signal malfunction Flashed
) B1553 A4 16 15 CAN communication signal malfunction Flashed
) B1557 b4 19 16 Vehicle speed sensor signal malfunction —
) B1561 54 17 17 Engine coolant temperature sensor signal malfunction Flashed

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Scan Tool DataS7RS0B7224007
As the data values given in the following are standard values estimated on the basis of values obtained from the
normally operation vehicles by using a scan tool, use them as reference values. Even when the vehicles are in good
condition, there may be cases where the checked values do not fall within each specifies data range. Therefore,
judgement as abnormal should not be ma de by checking with these data alone.
Scan Tool Data Condition Normal Condition / Reference
Va l u e
) TEMP CONT
SWITCH Each reference value is relative to the position of
temperature selector of HVAC control module. Max Cool, 18.5
°C (65 ° F), 19 °C (66
° C) – 31 °C (88 °F), 31.5 °C (89 °F),
Max Hot
) CABIN
TEMPERATURE Reference value is relative to in-car temperature. –6.5
°C – 57.25 ° C
(20.3 °F – 135.05 °F)
) OUTSIDE AIR TEMP Reference value is relative to outside air
temperature. –23.3
°C – 65.95 °C
(–9.94 °F – 150.71 °F)
) EVAPORATOR
TEMP Reference value is relative to temperature of
evaporator. –29.7
°C – 59.55 °C
(–21.46 °F – 139.19 °F)
) COOLANT TEMP At specified id le speed after warming up. 80 °C – 100 °C (176 ° F – 212 ° F)
) SUN LOAD Reference value depends on the situation. 0 W/m
2 – 4447.8 W/m2
)MODE CONT
SWITCH Each reference value is relative to the position of air
flow selector of HVAC control module.
AUTO, FACE, B/L, FOOT, D/F, DER
) FAN CONT SWITCH Each reference value is relative to the position of
blower speed selector of HVAC control module. AUTO, OFF, 1st, 2nd – 7th, 8th
) FAN DESIRED VOLT Reference value is relative to the position of blower
speed selector of HVAC control module. 0 – 16.0 V
) AIR MIX POS SEN Reference value is relative to the position of
temperature selector of HVAC control module. about 2.0 V (Max Hot)
about 4.0 V (Max Cool)
) MODE POS SENSOR Reference value is relative to the position of air flow
selector of HVAC control module. about 1.6 V (DEF)
about 4.0 V (VENT)
) A/C CONT SIG A/C system is ON. ON
A/C system is OFF. OFF
) BLOWER LOAD SIG Position of blower speed selector is 1st position or
more.
ON
Position of blower speed selector is OFF position. OFF
) AIR INTAKE MODE Fresh air (FRE) mode is activated. FRE
Recirculation air (REC) mode is activated. REC
AUTO mode is activated. AUTO
) REFRIGERANT
PRESSURE Engine running. A/C ON (A/C is operating)
at ambient temperature:
30
°C (86 °F) 1470 – 1770 kPa For more details,
refer to pressure of high pressure
gauge under “A/C System Performance Inspection”
A/C OFF (A/C is not
operating) at ambient
temperature: 30 °C (86
° F) and engine coolant
temperature: 90 ° – 100
° C 600 – 1000 kPa After longer than 10
min from A/C switch turned off
) A/C COMP CLUTCH Engine running. A/C switch and blower
motor switch turned ON
ON
A/C switch and/or blower
motor switch turned OFF OFF
) DFR INDICATOR Defroster indicator
lamp is lighted. ON
Defroster indicator la mp is not lighted. OFF
) VEHICLE SPEED At stop. OFF
0 km/h (0 mph)

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ECM Voltage Values Table for Relation of A/C Control
Repair Instructions
Operation Procedure for Refrigerant ChargeS7RS0B7226001
Refer to “Operation Procedure for Refrigerant Charge”.Terminal Wire Color Circuit Normal Value Condition
C37-14 GRY/RED Output of 5 V power
source 4.5 – 5.5 V Ignition switch turned ON
C37-15 BLK Ground for ECM Below 0.3 V Ignition switch turned ON
C37-24 LT GRN Engine coolant temp.
(ETC) sensor signal 3.3 – 3.8 V Ignition switch turned ON, ECT at 0
°C (32 ° F)
1.38 – 1.72 V Ignition switch turned ON, ECT at 50 °C (122 °F)
C37-30 BLK Ground for ECM Below 0.3 V Ignition switch turned ON
C37-55 ORN Ground for sensors Below 0.3 V Ignition switch turned ON
C37-58 BLK/ORN Ground for ECM Below 0.3 V Ignition switch turned ON E23-1 BLK/RED Main power supply 10 – 14 V Ignition switch turned ON
E23-3 RED CAN (high)
communication line
(active high signal)
for BCM and
combination meterRefer to “DTC P2101: Throttle Actu
ator Control Motor Circuit Range /
Performance in Section 1A”
E23-16 BLK/RED Main power supply 10 – 14 V Ignition switch turned ON
E23-18 WHT CAN (low)
communication line
(active low signal) for
BCM and
combination meterRefer to “DTC P2101: Throttle Actu
ator Control Motor Circuit Range /
Performance in Section 1A”
E23-19 BLU/WHT Electric load signal
for blower motor 10 – 14 V
Ignition switch turned ON, blower speed selector
OFF or between 1st and 5th position
0 – 1 V Ignition switch turned ON, blower speed selector
between 6th and HIGH position
E23-46 LT GRN Radiator fan relay
No.1 output 10 – 14 V
Ignition switch turned ON, engine coolant temp.:
below 95
°C (203 ° F), or A/C refrigerant pressure:
below 600 kPa (87 psi).
0 – 2 V Ignition switch turned ON, engine coolant temp.:
97.5
°C (207.5 °F) or higher, or A/C refrigerant
pressure: 1100 kPa (159.5 psi) or higher.
E23-47 GRY A/C compressor relay
output 10 – 14 V Engine running, A/C request signal high input
0 – 1 V Engine running, A/C request signal low input
E23-48 GRN Radiator fan relay
No.2 and No.3 output 10 – 14 V
Ignition switch turned ON, engine coolant temp.:
below 100
°C (212 °F), or A/C refrigerant
pressure: below 1200 kPa (174 psi).
0 – 2 V Ignition switch turned ON, engine coolant temp.:
102.5
°C (216.5 ° F) or higher, or A/C refrigerant
pressure: 1500 kPa (217.5 psi) or higher.
E23-55 RED A/C refrigerant
pressure sensor
signal 1.46 – 1.71 V
Engine running, A/C refrigerant pressure at 0.8
MPa (8.0 kg/cm
2) (A/C refrigerant pressure
measured by manifold gauge)
2.55 – 2.80 V Engine running, A/C refrigerant pressure at 1.6
MPa (16.0 kg/cm
2) (A/C refrigerant pressure
measured by manifold gauge)
E23-60 BRN/WHT Main power supply
relay output 10 – 14 V Ignition switch turned OFF
0 – 2 V Ignition switch turned ON