bcm SUZUKI SWIFT 2008 2.G Service Manual Online

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Manual Type 7B-7
Diagnostic Information and Procedures
A/C System Symptom DiagnosisS7RS0B7214001
ConditionPossible 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 “A/C Switch
Inspection”.
Blower speed selector faulty Check blower speed selector referring to
“Blower Speed Selector Inspection in Section
7A”.
Evaporator thermistor (Evaporator
temperature sensor) faulty Check evaporator thermistor (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.
ECM faulty Check ECM referring to “A/C System
Inspection at ECM”.
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”.
BCM faulty Check BCM referring to “Inspection of BCM
and its Circuits in Section 10B”.
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 Removal and
Installation in Section 1F”.
ECM and/or its circuit faulty Check ECM and/or its circuit referring to “A/C
System Inspection at ECM”.
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 relay faulty Check blower motor relay referring to “Blower
Motor Relay Inspection in Section 7A”.
Blower motor resistor faulty Check blower motor resistor referring to
“Blower Motor Resistor Inspection in Section
7A”.
Blower speed selector faulty Check blower speed selector referring to
“Blower Speed Selector Inspection in Section
7A”.
Wiring or grounding faulty Repair as necessary.
Blower motor faulty Check blower motor referring to “Blower Motor
Inspection in Section 7A”.

Downloaded from www.Manualslib.com manuals search engine 7B-36 Air Conditioning System: Automatic Type
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

Downloaded from www.Manualslib.com manuals search engine 7B-38 Air Conditioning System: Automatic Type
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

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-39
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”.

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-63
DTC B1546: A/C Refrigerant Pressure MalfunctionS7RS0B7224018
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1551: Serial Communication Circuit MalfunctionS7RS0B7224019
Wiring DiagramDTC detecting condition Trouble area
A/C refrigerant pressure sensor signal voltage is lower t han specified value
even though outside air temperature is higher than specified value for
specified time continuously. • Insufficient of refrigerant
• A/C refrigerant pressure sensor
• Outside air temperature sensor
• HVAC control module
Step
Action YesNo
1 A/C refrigerant pressure and outside air temperature
check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Start engine and select “DATA LIST” mode on scan tool.
3) Check “Refrigerant Pressure” and “Outside Air Temp” varies displayed on scan tool.
Is displayed each va ries described varies in “Scan Tool
Data”? Go to Step 2.
Check the amount of
refrigerant and system
for leaks.
2 A/C system performance check
1) Check A/C system performance referring to “A/C System
Performance Inspection”.
Is check result satisfactory? Go to Step 3.
Repair or replace
defective part.
3 A/C refrigerant pressure sensor check
1) Check A/C refrigerant pressure sensor referring to “A/C
Refrigerant Pressure Sensor and Its Circuit Inspection”.
Is check result satisfactory? Go to Step 4.
A/C refrigerant pressure
sensor faulty.
4 Outside air temperature sensor check
1) Check outside air temperature sensor referring to
“Information Display (Clock) Removal and Installation in
Section 9C”.
Is check result satisfactory? HVAC control module
faulty.
Outside air temperature
sensor faulty.
YEL17812910
65 431516 14 13 12 11
G52
789101920121112
65 431718 16 15 14 13
G51
G51-7
12V
2
3
G37-11
I5RS0A722016-01
1. HVAC control module 2. BCM3. Information display

Downloaded from www.Manualslib.com manuals search engine 7B-64 Air Conditioning System: Automatic Type
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1552: Serial Communication Signal MalfunctionS7RS0B7224020
DTC Detecting Condition and Trouble AreaDTC detecting condition Trouble area
Serial communication signal is higher than or lower than specified value for
specified time continuously. • Serial communication line of BCM
• BCM (included in junction block
assembly)
• Information display
• HVAC control module
Step Action YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Disconnect connector from information display.
3) Turn ignition switch ON and check DTC.
Is there DTC B1551? Go to Step 2.
Information display
faulty.
2 Wire harness check
1) Disconnect connectors from BCM and HVAC control
module.
2) Measure resistance between “G37-11” terminal of BCM connector and “G51-7” terminal of HVAC control module
connector.
Is resistance below 5
Ω? Go to Step 3. “YEL” wire open or high
resistance circuit.
3 Wire harness check
1) Measure resistance between “G51-7” terminal of HVAC
control module connector and vehicle body ground.
Is resistance infinity? Go to Step 4. “YEL” wire shorted to
ground circuit.
4 Wire harness check
1) Measure voltage between “G51-7” terminal of HVAC
control module connector and vehicle body ground with
ignition switch turned ON.
Is voltage 0 V? Go to Step 5. “YEL” wire shorted to
other circuit.
5 Serial communication signal check
1) Connect connectors to BCM and HVAC control module.
2) Using oscilloscope, check that serial communication
signal is outputted referring to “Reference waveform
No.8” of “Inspection of BCM and its Circuits in Section
10B”.
Is serial communication signal outputted at “G37-11”
terminal of BCM connector? HVAC control module
faulty.
BCM (included in
junction block
assembly) faulty.
DTC detecting condition
Trouble area
Data received by HVAC control module from BCM is erroneous continuously. • BCM (included in junction block assembly)
• HVAC control module

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-65
DTC Troubleshooting
DTC B1553: CAN Communication Signal MalfunctionS7RS0B7224021
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1557: Vehicle Speed Sensor Signal MalfunctionS7RS0B7224022
DTC Detecting Condition and Trouble Area
DTC TroubleshootingStep Action Yes No
1 Serial communication signal data check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Start engine and select “DATA LIST” mode on scan tool.
3) Check “Refrigerant Pressure”, “Vehicle Speed”, “Coolant Temp” and “Outside Air Temp” varies displayed on scan
tool.
Is displayed each va ries described varies in “Scan Tool
Data”? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
Go to Step 2.
2 Serial communication signal check
1) Connect connectors to BCM and HVAC control module.
2) Using oscilloscope, check that serial communication
signal is outputted referring to “Reference waveform
No.8” of “Inspection of BCM and its Circuits in Section
10B”.
Is serial communication signal outputted at “G37-11”
terminal of BCM connector? HVAC control module
faulty.
BCM (included in
junction block
assembly) faulty.
DTC detecting condition
Trouble area
HVAC control module receives error code fr om BCM continuously.• CAN communication circuit
• BCM (included in junction block assembly)
•ECM
• HVAC control module
Step Action YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check ECM and BCM for DTC.
Is there DTC(s)? Go to applicable DTC
diag. flow.
Substitute a known-
good HVAC control
module and recheck.
DTC detecting condition
Trouble area
HVAC control module receives error code from BCM continuously. • VSS circuit
• VSS
• HVAC control module
Step Action YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check ECM for DTC.
Is there DTC P0500? Go to “DTC P0480: Fan
1 (Radiator Cooling
Fan) Control Circuit in
Section 1A”.
Substitute a known-
good HVAC control
module and recheck.

Downloaded from www.Manualslib.com manuals search engine 7B-66 Air Conditioning System: Automatic Type
DTC B1561: Engine Coolant Temperature Sensor Signal MalfunctionS7RS0B7224023
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1562: Outside Air Temperature Sensor Signal MalfunctionS7RS0B7224024
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1563: A/C Refrigerant Pressure Sensor Signal MalfunctionS7RS0B7224025
DTC Detecting Condition and Trouble Area
DTC TroubleshootingDTC detecting condition Trouble area
HVAC control module receives error code from BCM continuously. • ECT sensor circuit
• ECT sensor
• HVAC control module
StepAction YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check ECM for DTC.
Are there DTC P0116, P0117 or P0118? Go to applicable DTC
diag. flow.
Substitute a known-
good HVAC control
module and recheck.
DTC detecting condition
Trouble area
HVAC control module receives er ror code from BCM continuously. • Outside air temperature sensor
circuit
• Outside air temperature sensor
• HVAC control module
Step Action YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check BCM for DTC.
Are there DTC B1141, B1142 or B1143? Go to applicable DTC
diag. flow.
Substitute a known-
good HVAC control
module and recheck.
DTC detecting condition
Trouble area
HVAC control module receives er ror code from BCM continuously. • A/C refrigerant pressure sensor
circuit
• A/C refrigerant pressure sensor
• HVAC control module
Step Action YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check ECM for DTC.
Are there DTC P0532 or P0533? Go to applicable DTC
diag. flow.
Substitute a known-
good HVAC control
module and recheck.

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-67
Inspection of HVAC Control Module and Its CircuitS7RS0B7224026
HVAC control module and its circuits can be checked at HVAC control module wiring couplers by measuring voltage.
CAUTION!
HVAC control module can not be checked by itself. It is strictly prohibited to connect voltmeter to
HVAC control module with couplers disconnected from it.

Voltage Check
1) Remove HVAC control module referring to “HVAC Control Module Removal and Installation”.
2) Check voltage at each terminal.
NOTE
As each terminal voltage is affected by the battery voltage, confirm that it is 11 V or more when ignition
switch is ON.

7812910
65 431516 14 13 12 11
G52
789101920121112
65 431718 16 15 14 13
G51
1
2
I5RS0A722017-02
1. HVAC control module2. HVAC control module connector (viewed from harness side)
Terminal Wire Color CircuitNormal
Vo l ta g e Condition
G51-1 BRN/WHT Air flow control actuator
(DEF) 10 – 14 V
Ignition switch turned ON, ai
r flow control actuator is
working in operation fr om VENT to DEF position
0 – 1 V Ignition switch turned ON, except the above condition
G51-2 BRN/YEL Air flow control actuator
(FACE) 10 – 14 V
Ignition switch turned ON, ai
r flow control actuator is
working in operation fr om DEF to VENT position
0 – 1 V Ignition switch turned ON, except the above condition
G51-3 GRY/BLU Temperature control
actuator (COOL) 10 – 14 VIgnition switch turned ON, temperature control
actuator is working in ope
ration from HOT to COOL
position
0 – 1 V Ignition switch turned ON, except the above condition
G51-4 GRY/RED Temperature control
actuator (HOT) 10 – 14 VIgnition switch turned ON, temperature control
actuator is working in operation from COOL to HOT
position
0 – 1 V Ignition switch turned ON, except the above condition
G51-5 PPL/WHT Serial communication line
of data link connector 10 – 14 V Ignition switch turned ON
G51-6 — — — —
G51-7 YEL Serial communication line
of BCM Refer to “Inspection of BCM a
nd its Circuits in Section 10B”

Downloaded from www.Manualslib.com manuals search engine 7B-68 Air Conditioning System: Automatic Type
G51-8 BLU/REDBlower motor control
voltage feedback 10 – 14 V Ignition switch turned ON, blower speed selector OFF
About 8.5 V Ignition switch turned ON, blower speed selector 1st
position
About 6.5 V Ignition switch turned ON, blower speed selector 2nd
position
About 5.5 V Ignition switch turned ON, blower speed selector 3rd
position
About 4.0 V Ignition switch turned ON, blower speed selector 4th
position
About 3.0 V Ignition switch turned ON, blower speed selector 5th
position
About 2.0 V Ignition switch turned ON, blower speed selector 6th
position
About 1.0 V Ignition switch turned ON, blower speed selector 7th
position
Below 1.0 V Ignition switch turned ON, blower speed selector HIGH
position
G51-9 GRY Blower motor controller 0 – 1 V
Ignition switch turned ON, blower speed selector OFF
position
2 – 3 V Ignition switch turned ON, blower speed selector
between 1st and HIGH position
G51-10 BLK/RED Rear defogger indicator 0 – 1 V Ignition switch turned ON, rear defogger switch OFF
10 – 14 V Ignition switch turned ON, rear defogger switch ON
G51-11 RED/YEL Illumination switch 0 – 1 V Ignition switch turned ON, lighting switch OFF position
10 – 14 V Ignition switch turned ON, lighting switch ON position
G51-12 BLK/YEL Illumination ground 0 – 1 V Full-time
G51-13 — — — —
G51-14 — — — —
G51-15 RED Air intake actuator
(RECIRCULATION AIR) 0 – 1 VIgnition switch turned ON, air intake selector is
recirculation air mode or air intake actuator is working
in operation to recirculation air position or fresh air
position.
10 – 14 V Ignition switch turned ON, ai
r intake selector is fresh
air mode (air intake actuator fresh air position).
G51-16 GRN/RED Air intake actuator
(MIX AIR) 10 – 14 V
Ignition switch turned ON, air intake actuator is
recirculation air or fresh air position.
0 – 1 V Ignition switch turned ON, air intake actuator is mix air
position or air intake actuator is working in operation to
recirculation air position or fresh air position.
G51-17 GRN Air intake actuator
(FRESH AIR) 0 – 1 V
Ignition switch turned ON, ai
r intake selector is fresh
air mode or air intake actuator is working in operation
to recirculation air position or fresh air position.
10 – 14 V Ignition switch turned ON, air intake selector is
recirculation air mode (air intake actuator recirculation
air position).
G51-18 GRN/WHT A/C switch signal Refer to “Inspe ction of BCM and its Circuits in Section 10B”
G51-19 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 – 2 V Ignition switch turned ON, blower speed selector
between 6th and HIGH position
G51-20 BRN Rear defogger switch 0 – 1 V
Ignition switch turned ON, rear defogger switch ON
(rear defogger switch is kept in push) position
4 – 6 V Ignition switch turned ON, rear defogger switch OFF
position
Terminal Wire Color Circuit
Normal
Vo l ta g e Condition