hvac control module SUZUKI SWIFT 2005 2.G Service User Guide

Downloaded from www.Manualslib.com manuals search engine 7B-34 Air Conditioning System: Automatic Type
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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Electronic Control System Location
NOTE
The figure shows left-hand steering vehicle. For right-hand steering vehicle, parts with (*) are installed
at the opposite side.

1
2
3 * 4 *
5
6 *
7 *
8 *
9 *
10 *
21
11
12 13
14
15161718
19
20
I5RS0C722001-01
1. ECT sensor
7. Blower motor13. AUTO switch19. MODE (air flow) selector
2. Outside air temperature sensor 8. Blower motor controller 14. Temperature selector 20. Blower speed selector
3. Sunload sensor 9. Temperature control actuator15. OFF switch21. HVAC control module
4. Air flow control actuator 10. Inside air temperature sensor 16. Air intake selector
5. Evaporator temperature sensor 11. Defroster switch 17. A/C switch
6. Air intake actuator 12. Display 18. Rear defogger switch

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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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A/C System Wiring DiagramS7RS0B7222002
6
13
15
1610
11
12 9
12V
5V
5V5V
12V
12V
5V 5V
5V +BB
PNK/BLK
WHT/BLK
GRYBLK
WHT/BLU
WHT YEL
ORN
BRN/WHT
BRN/YEL
GRY/BLU
GRY/RED
PNK
YEL/BLK
BLK/ORN
PPL/WHT
12V BLK/YEL
WHT
ORN
ORN
ORN
5V
BLK/RED
BRN
RED/BLK
5V
5VGRY/REDRED
ORN
BLU/WHT
14
YEL/REDYEL/BLK
GRN/WHT
12V
YEL
L+
H+
L
H
WHTGRYBLK/RED
REDWHTREDWHT
M
M
WHT/RED
5
BLU
YEL
WHT
WHT/BLU
RED/BLKWHT
RED/YEL
BLU/YEL
LT GRN
GRN
BLU/RED
G52-6
G52-4
G52-2
G52-5
G51-1
G51-2
G52-14
G51-3
G51-4
G52-1
G52-13
G52-3
G51-19
G51-7
G51-18
G51-10
G51-20
G51-5
G52-11
G51-9
G51-8
G51-12
G51-11
G52-16
5V
12V
5V
12V
LT GRNORN
5V
23
1
2
3 4
8
17
18 19
20
21
22
24
25
26
27
28
29
30
36 35 34 33 32 31 37
38 3938
41 40
42
43
44
MRED/BLK
GRN/RED
G52-8G51-15
G51-17G51-16
REDGRN
BLK/YEL
BLK/WHT
M7
I7RS0A722001-01
1. Main fuse box 12. Temperature control actuator 23. HVAC control module 34. Defroster switch
2. Ignition switch 13. Inside air temperature sensor 24. BCM 35. AUTO switch
3. Individual circuit fuse box No.1 box 14. Outside air temper ature sensor 25. A/C refrigerant pressure sensor 36. OFF switch

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Diagnostic Information and Procedures
A/C System Symptom DiagnosisS7RS0B7224001
4. Rear defogger relay 15. Evaporator temperature sensor 26. Radiator cooling fan relay No.1 37. Rear defogger switch
5. Rear defogger 16. Sunload sensor 27. Radiator cooling fan relay No.2 38. To BCM
6. Blower motor relay 17. Junction block assembly 28. Radiator cooling fan relay No.3 39. To ECM
7. Blower motor 18. ECM 29. Information display 40. To main relay
8. Blower motor controller 19. ECT sensor 30. Lighting switch 41. To main fuse
9. DLC 20. Radiator cooling fan motor 31. A/C switch 42. Back-light
10. Air intake actuator 21. Compressor relay 32. MODE (air flow) selector 43. Defroster indicator 11. Air flow control actuator 22. Compressor 33. Air intake selector 44. Rear defogger indicator
Condition Possible cause Correction / Reference Item
No cool air comes out (A/
C system does not
operate) No refrigerant
Perform recovery, evacuation and charge
referring to “Operation Procedure for
Refrigerant Charge”.
Fuse blown Check related fuses, and then check for short
circuit to ground.
A/C switch faulty Check A/C switch referring to “Inspection of
HVAC Control Module and Its Circuit”.
Evaporator temperature sensor faulty Check evaporator temperature sensor
referring to “Evaporator Thermistor
(Evaporator Temperature Sensor) Inspection”.
A/C refrigerant pressure sensor faulty Check A/C refrigerant pressure sensor
referring to “A/C Refrigerant Pressure Sensor
and Its Circuit Inspection”.
Wiring or grounding faulty Repair as necessary.
ECT sensor faulty Check ECT sensor referring to “ECT Sensor
Inspection in Section 1C”.
ECM faulty Check ECM referring to “A/C System
Inspection at ECM”.
HVAC control module faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
Magnet clutch faulty Check magnet clutch. Referring to “Magnet
Clutch Inspection”.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Compressor faulty Check compressor.
Compressor relay faulty Check compressor relay referring to
“Compressor Relay Inspection”.
Temperature selector, blower speed
selector, and/or air flow selector faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
BCM faulty Check BCM referring to “Inspection of BCM
and its Circuits in Section 10B”.

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No cool air comes out
(radiator cooling fan
motor does not operate)Fuse blown
Check related fuses, and then check for short
circuit to ground.
Wiring or grounding faulty Repair as necessary.
Radiator cooling fan motor relay faulty Check radiator cooling fan motor relay
referring to “Radiator Cooling Fan Relay
Inspection in Section 1F”.
Radiator cooling fan motor faulty Check radiator cooling fan motor referring to
“Radiator Cooling Fan Motor On-Vehicle
Inspection in Section 1F”.
ECM faulty Check ECM referring to “A/C System
Inspection at ECM”.
HVAC control module faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
No cool air comes out
(blower motor does not
operate) Fuse blown
Check related fuses, and then check for short
circuit to ground.
Blower motor controller faulty Check blower motor controller referring to
“Blower Motor Controller Inspection”.
Blower speed selector faulty Check blower speed selector referring to
“Inspection of HVAC Control Module and Its
Circuit”.
HVAC control module faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
Wiring or grounding faulty Repair as necessary.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Blower motor relay faulty Check blower motor relay referring to “Blower
Motor Relay Inspection in Section 7A”.
Condition Possible cause Correction / Reference Item

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Cool air does not come
out or insufficient cooling
(A/C system normal
operation)Insufficient or excessive charge of
refrigerant
Check the amount of refrigerant and system
for leaks.
Condenser clogged Check condenser referring to “Condenser
Assembly On-Vehicle Inspection”.
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”.
Evaporator temperature sensor faulty Check evaporator temperature sensor
referring to “Evaporator Thermistor
(Evaporator Temperature Sensor) Inspection”.
Expansion valve faulty Check expansion valve referring to “Expansion
Valve Inspection”.
Desiccant clogged Replace receiver/dryer.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Magnet clutch faulty Check magnet clutch. Referring to “Magnet
Clutch Inspection”.
Compressor faulty Check compressor.
Air in A/C system Replace receiver/dryer, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Air leaking from HVAC unit or air duct Repair as necessary.
Heater and ventilation system faulty Check HVAC unit.
Temperature selector faulty Check temperature selector referring to
“Inspection of HVAC Control Module and Its
Circuit”.
HVAC control module faulty Check HVAC control module referring to
“Inspection of HVAC Control Module and Its
Circuit”.
Temperature control actuator faulty Check temperature control actuator referring to
“Temperature Control Actuator Inspection”.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.
Excessive compressor oil in A/C system Drain excessive compressor oil from A/C
system circuit and compressor.
Cool air does not come
out only intermittently Wiring connection faulty
Repair as necessary.
Expansion valve faulty Check expansion valve referring to “Expansion
Valve Inspection”.
Excessive moisture in A/C system Replace receiver/dryer, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Magnet clutch faulty Check magnet clutch. Referring to “Magnet
Clutch Inspection”.
Excessive amount of refrigerant Check the amount of refrigerant.
Cool air comes out only at
high speed Condenser clogged
Check condenser referring to “Condenser
Assembly On-Vehicle Inspection”.
Insufficient charge of refrigerant Check the amount of refrigerant and system
for leaks.
Air in A/C system Replace receiver/dryer, and then perform
evacuation and charge referring to “Operation
Procedure for Refrigerant Charge”.
Compressor drive belt loosened or
broken Adjust or replace drive belt.
Compressor faulty Check compressor.
Condition Possible cause Correction / Reference Item

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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