2006 SUZUKI SX4 speed

Downloaded from www.Manualslib.com manuals search engine 7B-40 Air Conditioning System: Automatic Type
HVAC Control DescriptionS6RW0D7221002
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, ECT 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, ECT 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 air flow control
actuator so that the current air flow control 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)A/C Compressor Relay Control
HVAC control module outputs A/C switch ON signal to
ECM via BCM when the vehicle state satisfy conditions
described below.
• A/C switch is ON
• Evaporator temperature is higher than specified value
• Evaporator temperature sensor malfunction is not
detected
Communication of ECM and BCM is established by CAN
(Controller Area Network). (For more detail of CAN
communication, refer to “CAN Communication System
Description in Section 1A”).
ECM turns ON the A/C compressor relay when the
vehicle state satisfy conditions described below.
• A/C switch ON signal is inputted
• A/C refrigerant pressure is within specified range
• Engine speed is within specified range
• Engine coolant temperature is lower than specified
value
• Throttle opening is lower than specified value
• Vehicle is not in either state of starting or quick
acceleration
• ECT sensor malfunction is not detected
• A/C refrigerant pressure sensor malfunction is not
detected
Condenser Cooling Fan Relay Control
ECM turn ON the condenser cooling fan relay at the
same time when ECM turn ON the A/C compressor
relay.
Sub-Cool A/C System DescriptionS6RW0D7221003
Refer to “Sub-Cool A/C System Description”.

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-41
On-Board Diagnostic System DescriptionS6RW0D7221004
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 detects malfunctions, which may
occur in the following area.
• Inside air temperature sensor
• Evaporator temperature sensor
• Sunload sensor
• Temperature control actuator
• Air flow control actuator
• Temperature selector of HVAC control module
• Air flow selector of HVAC control module
• Blower speed selector of HVAC control module
• Back-up power supply circuit of HAVC control module
• Serial communication line between BCM and HVAC
control module• Received data from BCM as follows
– Outside air temperature sensor signal
– ECT sensor signal
– A/C refrigerant pressure sensor signal
– VSS signal
– Engine type signal
– Combination meter spec signal
– CAN communication circuit failure signal
When HVAC control module detects malfunction, the “A/
C” indicator light (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
A/C System Air Flow DiagramS6RW0D7222001
Refer to “A/C System Air Flow Diagram”.
1
I5RW0A722002-01

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-43
Component Location
A/C System Major Components LocationS6RW0D7223001
Refer to “A/C System Major Components Location”.
[A]: Illumination control model 10. Air intake actuator 22. Compressor 34. “A/C” indicator light
[B]: Junction block with BCM 11. Air flow control actuator 23. HVAC control module 35. Rear defogger switch
[C]: Junction block without BCM 12. Temperature control actuator 24. BCM 36. Rear defogger indicator
1. Main fuse box 13. Inside air temperature sensor 25. A/C refrigerant pressure sensor 37. To other control module
2. Ignition switch 14. Outside air temperature sensor 26. Condenser cooling fan relay 38. Indicator light, switch,
selector
3. CAN junction connector 15. Evaporator temperature sensor 27. Information display 39. “FRE” indicator light
4. Rear defogger relay 16. Sunload sensor 28. Lighting switch 40. “REC” indicator light
5. Rear defogger 17. Junction block assembly 29. A/C switch 41. Temperature selector
6. Blower motor relay 18. ECM 30. Air intake selector 42. Blower speed selector
7. Blower motor 19. ECT sensor 31. To BCM 43. MODE (air flow) selector
8. Blower motor controller 20. Condenser cooling fan motor 32. ABS control module 44. Tail light
9. DLC 21. Compressor relay 33. Illumination light 45. Main relay

Downloaded from www.Manualslib.com manuals search engine 7B-44 Air Conditioning System: Automatic Type
Electronic Control System Components LocationS6RW0D7223002
NOTE
The figure shows left-hand steering vehicle. For right-hand steering vehicle, parts with (*) are installed
at the opposite side.

[A]
2
3
5
1
4
78*
18
19
20
23
22 219*
10*
11*
12*
13*
15* 16* 17
14*
8*6
I6RW0C722003-01
[A]: Junction block assembly viewed from relay
side8. Junction block assembly 16. Blower motor controller
1. A/C refrigerant pressure sensor 9. Sunload sensor 17. HVAC control module
2. Compressor relay 10. Inside air temperature sensor 18. Temperature selector
3. Condenser cooling fan relay 11. Air flow control actuator 19. Blower speed selector
4. Outside air temperature sensor 12. Temperature control actuator 20. MODE (air flow) selector
5. ECT sensor 13. Evaporator temperature sensor 21. A/C switch
6. Condenser cooling fan 14. Air intake actuator 22. Air intake selector
7. Blower motor relay 15. Blower motor 23. Rear defogger switch

Downloaded from www.Manualslib.com manuals search engine 7B-48 Air Conditioning System: Automatic Type
Cool air does not come
out or insufficient cooling
(A/C compressor normal
operation)Insufficient or excessive charge of
refrigerantCheck the amount of refrigerant and system
for leaks.
Condenser cloggedCheck condenser referring to “Condenser
Assembly On-Vehicle Inspection”.
A/C evaporator clogged or frostedCheck A/C evaporator and evaporator
temperature sensor referring to “Evaporator
Inspection” and “Evaporator Temperature
Sensor Inspection”.
Evaporator temperature sensor faultyCheck evaporator temperature sensor
referring to “Evaporator Temperature Sensor
Inspection”.
Expansion valve faultyCheck expansion valve referring to “Expansion
Valve Inspection”.
Desiccant cloggedCheck desiccant and cap with filter.
Compressor drive belt loosened or
brokenAdjust or replace drive belt.
Magnet clutch faultyCheck magnet clutch referring to “Magnet
Clutch Inspection”.
Compressor faultyCheck compressor.
Air in A/C systemReplace condenser, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Air leaking from HVAC unit or air ductRepair as necessary.
Heater and ventilation system faultyCheck HVAC unit.
HVAC control module faultyCheck HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
Temperature control actuator faultyCheck temperature control actuator referring to
“Temperature Control Actuator and Its Circuit
Inspection”.
Blower motor faultyCheck blower motor referring to “Blower Motor
Inspection in Section 7A”.
Excessive compressor oil in A/C systemDrain excessive compressor oil from A/C
system circuit and compressor.
Cool air does not come
out only intermittentlyWiring connection faultyRepair as necessary.
Expansion valve faultyCheck expansion valve referring to “Expansion
Valve Inspection”.
Excessive moisture in A/C systemReplace condenser, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Magnet clutch faultyCheck magnet clutch referring to “Magnet
Clutch Inspection”.
Excessive amount of refrigerantCheck the amount of refrigerant.
Cool air comes out only at
high speedCondenser cloggedCheck condenser referring to “Condenser
Assembly On-Vehicle Inspection”.
Insufficient charge of refrigerantCheck the amount of refrigerant and system
for leaks.
Air in A/C systemReplace condenser, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Compressor drive belt loosened or
brokenAdjust or replace drive belt.
Compressor faultyCheck compressor.
Cool air does not come
out only at high speedExcessive amount of refrigerantCheck the amount of refrigerant.
A/C evaporator frostedCheck A/C evaporator and evaporator
temperature sensor referring to “Evaporator
Inspection” and “Evaporator Temperature
Sensor Inspection”. Condition Possible cause Correction / Reference Item

Downloaded from www.Manualslib.com manuals search engine 7B-50 Air Conditioning System: Automatic Type
Not Using SUZUKI Scan Tool
NOTE
In case of malfunction of temperature
selector, blower speed selector and air flow
selector, DTC can not be checked by the
following procedure. Use SUZUKI scan tool
for DTC check.

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

2) Set the following selectors to specified positions
below respectively with ignition switch off position.
• Temperature selector (1) is maximum cool
position
• Blower speed selector (2) is OFF position
• Air flow selector (3) is AUTO position
3) While pressing A/C switch (4) and air intake selector
(5) simultaneously, turn ignition switch to ON
position.
4) Wait for about 5 seconds (start of diagnosis).
5) Read flashing pattern of “FRE” (6) and “REC” (7)
indicator lights which represents DTC and write it
down.
NOTE
• When 2 or more current 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.
• Pressing “A/C” switch alternates display
of current DTC and history DTC. “A/C”
indicator light (8) remains off when display
is in current DTC mode and it lights up
when display is in history DTC mode.
• When a history DTC is indicated while 2 or
more history DTCs are detected, it is
possible to have other history DTC(s)
stored in HVAC control module displayed
by pressing the air intake selector.

Example: When inside air temperature sensor
circuit malfunction (Open) is set
Example: When VSS signal failure (Data error) is
set
6) After completing above check, turn ignition switch to
“OFF” position.
[A]: “REC” indicator light L: OFF
[B]: “FRE” indicator light a. About 0.5 seconds
H: ON b. About 2 seconds
[A]: “REC” indicator light a. About 0.5 seconds
[B]: “FRE” indicator light b. About 3 seconds
H: ON c. About 1.5 seconds
L: OFF
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Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-53
) B1521Blower Speed
Selector
Malfunction16 1Signal voltage of blower speed selector in HVAC
control module is higher than specification.Flashed
16 2Signal voltage of blower speed selector in HVAC
control module is lower than specification.Flashed
) B1522Air Flow Selector
Malfunction17 1Signal voltage of airflow selector in HVAC control
module is higher than specification.Flashed
17 2Signal voltage of airflow selector in HVAC control
module is lower than specification.Flashed
) B1541Back-up Power
Supply Circuit
Malfunction14 1• Back-up power supply voltage of HVAC control
module is higher than or lower than
specification.
• When connect battery with vehicle and then,
turn ignition switch to ON position for first time.—
) B1546A/C Refrigerant
Pressure
Malfunction13 5• Signal voltage of outside air temperature sensor
is more than specified value. However, A/C
refrigerant pressure is less than specified value.
• Insufficient refrigerant in A/C system.—
) B1551Serial
Communication
Circuit
Malfunction91Circuit voltage of serial communication circuit is
higher than specification.Flashed
92Circuit voltage of serial communication circuit is
lower than specification.Flashed
) B1552HVAC Control
Module Check
Sum Error94HVAC control module received unspecified data
from BCM more than 8 times.Flashed
) B1553CAN
Communication
Circuit
Malfunction10 4HVAC control module received signal indicating
reception error from ECM.Flashed
) B1557VSS Signal
Failure11 4HVAC control module receives invalid data of VSS
signal from BCM.—
) B1561ECT signal
Failure54HVAC control module receives invalid data of ECT
signal from BCM.Flashed
) B1562Outside
Temperature
Sensor Signal
Failure14HVAC control module receives invalid data of
outside air temperature sensor signal from BCM.Flashed
) B1563A/C Refrigerant
Pressure Sensor
Signal Failure13 4HVAC control module receives invalid data of A/C
refrigerant pressure sensor signal from BCM.—
) B1570Engine Type
Signal Failure20 4HVAC control module receives invalid data of
engine type signal from BCM.—
) B1571Combination
Meter Spec
Signal Failure21 4HVAC control module receives invalid data of
combination meter spec signal from BCM.—
NO CODE Normal See NOTE below — —DTC No.
(displayed
on SUZUKI
scan tool)Detection itemDTC (indicated on
HVAC control
module)
Condition when trouble detected (DTC is
determined when following condition detected)“A/C”
indicator
light Indicated
by “REC”
indicator
lightIndicated
by “FRE”
indicator
light

Downloaded from www.Manualslib.com manuals search engine 7B-54 Air Conditioning System: Automatic Type
DTC of A/C System detected by ECM
NOTE
When no DTC is detected, “FRE” [A] and “REC” [B] indicator lights on HVAC control module flash at
the same time in specific pattern.

Fail-Safe TableS6RW0D7224007
When any of the following malfunctions (DTCs) is detected, fail-safe mode is activated.
However, when HVAC control module detects normal operation of A/C system, fail-safe mode is canceled. DTC No. Detection itemDetecting condition
(DTC will set when detecting)MIL
P0481 Fan 2 Control Circuit
Refer to “Fail-Safe Table in Section 1A”. P0532A/C Refrigerant Pressure
Sensor Circuit Low
P0533A/C Refrigerant Pressure
Sensor Circuit High
H: ON a. About 3 seconds
L: OFF b. About 1 seconds
DTC No. Trouble AreaFail-Safe Operation
When ignition switch is turned ON
after malfunction is already detectedWhen malfunction is detected during
ignition switch is ON
) B1502Inside air temperature
sensor circuitHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that inside air temperature is
25 °C (77 °F).
) B1503A/C evaporator
temperature sensor
circuitHVAC control module assuming that
evaporator temperature is 0 °C (32 °F).• HVAC control module turns off A/C
switch signal.
• HVAC control module controls
actuators assuming that evaporator
temperature is 0 °C (32 °F).
) B1504 Sunload sensor circuitHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that amount of sunlight is 0 W/
m
2.
) B1520Temperature selector
malfunctionHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that setting of temperature
selector is 25 °C (77 °F) position.
) B1521Blower speed selector
malfunctionHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that setting of blower speed
selector is low (1st) position.
) B1522Air flow selector
malfunctionHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that setting of air flow selector
is DEF position.
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I5RW0A722008-01