Ground SUZUKI SWIFT 2008 2.G Service Workshop Manual
Page 1003 of 1496
Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-55
DTC B1512: Air flow Control Actuator (Position Sensor) and/or Its Circuit MalfunctionS7RS0B7224014
Wiring Diagram
DTC Detecting Condition and Trouble Area8
Position sensor signal circuit check
1) Measure resistance between “YEL” wire terminal of 
temperature control actuator  connector and vehicle body 
ground.
Is resistance infinity? Go to Step 9. “YEL” wire shorted to 
ground circuit.
9 Position sensor signal circuit check
1) Measure voltage between “YEL” wire terminal of 
temperature control actuator  connector and vehicle body 
ground with ignition switch turned ON.
Is voltage 0 V? Go to Step 10. “YEL” wire shorted to 
other circuit.
10 Position sensor ground circuit check
1) Connect HVAC control module connector with ignition 
switch turned OFF.
2) Measure resistance between “ORN” wire terminal of  temperature control actuator  connector and vehicle body 
ground.
Is resistance below 5 
Ω? Go to Step 12. Go to Step 11.
11 Position sensor ground circuit check
1) Measure resistance between “G52-3” terminal of HVAC 
control module connector and vehicle body ground.
Is resistance below 5 
Ω? “ORN” wire open or high 
resistance circuit.
HVAC control module 
faulty.
12 Temperature control actuator check
1) Check temperature control actuator referring to 
“Temperature Control Actuator Inspection”.
Is it in good condition? HVAC control module 
faulty.
Temperature control 
actuator faulty.
Step Action Yes No
7812910
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G52
789101920121112
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G51
M 12V
5V 5V
WHT/BLU
WHT
BRN/WHT
BRN/YEL
2
1
ORN
G51-1
G51-2
G52-1
G52-14
G52-3
3
4
I5RS0A722014-01
1. HVAC control module 2. Air flow control actuator3.To temperature control actuator 4. To other sensors
DTC Detecting Condition Trouble Area
Air flow control actuator position sensor signal voltage is higher than or lower 
than specified value for specified time continuously. • Air flow control actuator circuit
• Air flow control actuator
• HVAC control module  
Page 1004 of 1496
Downloaded from www.Manualslib.com manuals search engine 7B-56 Air Conditioning System: Automatic Type
DTC TroubleshootingStep Action YesNo
1 Position sensor power supply circuit check
1) Disconnect air flow control actuator connector.
2) Check for proper connection to  air flow control actuator 
at “WHT”, “WHT/BLU” and “ORN” wire terminals.
3) If OK, measure voltage between “WHT” wire terminal of  air flow control actuator  connector and vehicle body 
ground with ignition switch turned ON.
Is voltage 4 – 6 V? Go to Step 6.
Go to Step 2.
2 Position sensor power supply circuit check
1) Disconnect temperature control actuator connector with 
ignition switch turned OFF.
2) Measure voltage between “WHT” wire terminal of air flow  control actuator connector and vehicle body ground with 
ignition switch turned ON.
Is voltage 4 – 6 V? Temperature control 
actuator faulty.
Go to Step 3.
3 Position sensor power supply circuit check
1) Disconnect connector from HVAC control module with 
ignition switch turned OFF.
2) Check for proper connection to HVAC control module  connector at “G52-1”, “G52-3” and “G52-14” terminals.
3) If OK, measure resistance between “WHT” wire terminal  of air flow control actuator connector and “G52-1” 
terminal of HVAC control module connector.
Is resistance below 5 
Ω? Go to Step 4. “WHT” wire open or 
high resistance circuit.
4 Position sensor power supply circuit check
1) Measure resistance between “WHT” wire terminal of air 
flow control actuator connector and vehicle body ground.
Is resistance infinity? Go to Step 5. “WHT” wire shorted to 
ground circuit.
5 Position sensor power supply circuit check
1) Measure voltage between “WHT” wire terminal of air flow 
control actuator connector and vehicle body ground with 
ignition switch turned ON.
Is voltage 0 V? Go to Step 6. “WHT” wire shorted to 
other circuit.
6 Position sensor signal circuit check
1) Connect HVAC control module connector with ignition 
switch turned OFF.
2) Measure voltage between “WHT/BLU” wire terminal of  air flow control actuator  connector and vehicle body 
ground with ignition switch turned ON.
Is voltage 4 – 6 V? Go to Step 10. Go to Step 7.
7 Position sensor signal circuit check
1) Disconnect connector from HVAC control module with 
ignition switch turned OFF.
2) Measure resistance between “WHT/BLU” wire terminal  of air flow control actuator connector and “G52-14” 
terminal of HVAC control module connector.
Is resistance below 5 
Ω? Go to Step 8. “WHT/BLU” wire open 
or high resistance 
circuit.  
Page 1005 of 1496
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DTC B1513: Temperature Control Actuator and/or Its Circuit MalfunctionS7RS0B7224015
Wiring Diagram
DTC Detecting Condition and Trouble Area8
Position sensor signal circuit check
1) Measure resistance between “WHT/BLU” wire terminal 
of air flow control actuator connector and vehicle body 
ground.
Is resistance infinity? Go to Step 9.  “WHT/BLU” wire 
shorted to ground 
circuit.
9 Position sensor signal circuit check
1) Measure voltage between “WHT/BLU” wire terminal of 
air flow control actuator  connector and vehicle body 
ground with ignition switch turned ON.
Is voltage 0 V? Go to Step 10. “WHT/BLU” wire 
shorted to other circuit.
10 Position sensor ground circuit check
1) Connect HVAC control module connector with ignition 
switch turned OFF.
2) Measure resistance between “ORN” wire terminal of air  flow control actuator connector and vehicle body ground.
Is resistance below 5 
Ω? Go to Step 12. Go to Step 11.
11 Position sensor ground circuit check
1) Measure resistance between “G52-3” terminal of HVAC 
control module connector and vehicle body ground.
Is resistance below 5 
Ω? “ORN” wire open or high 
resistance circuit.
HVAC control module 
faulty.
12 Air flow control actuator check
1) Check air flow control actuator referring to “Air Flow 
Control Actuator Inspection”.
Is it in good condition? HVAC control module 
faulty.
Air flow control actuator 
faulty.
Step Action Yes No
7812910
65 431516 14 13 12 11
G52
789101920121112
65 431718 16 15 14 13
G51
M 12V
5V 5V
YEL
WHT
GRY/BLU
GRY/RED
2
1
ORN
G51-3
G51-4
G52-1
G52-13
G52-3
3
4
I5RS0A722013-01
1. HVAC control module 2. Temperature control actuator 3. To air flow control actuator 4. To other sensors
DTC Detecting Condition Trouble Area
Difference between target opening an d actual opening is higher than 
specified value even though temperature control actuator has operated for 16 
seconds. • Temperature control actuator circuit
• Temperature control linkage
• Temperature control actuator
• HVAC unit
• HVAC control module  
Page 1006 of 1496
Downloaded from www.Manualslib.com manuals search engine 7B-58 Air Conditioning System: Automatic Type
DTC Troubleshooting
NOTE
• When DTC B1502, B1503 and B1514 are indicated together, it is possible that “ORN” wire circuit open.
• When DTC B1514 is indicated together, it is possible that “WHT” wire circuit open.
 
Step Action YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned 
OFF.
2) Turn ON ignition switch and check DTC.
Is there DTC B1511? Go to applicable DTC 
diag. flow.
Go to Step 2.
2 Visual check
1) Check if there is any obstruction in operating range of 
actuator linkage and if  actuator linkage operates 
smoothly.
Is it in good condition? Go to Step 3.
Obstruction in operating 
range of actuator 
linkage, actuator linkage 
faulty and/or internal 
fault of HVAC unit.
3 Wire harness check
1) Disconnect connector from temperature control actuator 
with ignition swit ch turned OFF.
2) Check for proper connection to temperature control  actuator connector at “GRY /BLU” and “GRY/RED” wire 
terminals.
3) If OK, measure voltage between “GRY/BLU” wire  terminal of temperature control actuator connector and 
vehicle body ground with ignition switch turned ON when 
temperature selector is operation to COOL direction.
Is voltage 10 – 14 V? Go to Step 7.
Go to Step 4.
4 Wire harness check
1) Disconnect connector from HVAC control module with 
ignition switch turned OFF.
2) Check for proper connection to HVAC control module  connector at “G51-3” and “G51-4” terminals.
3) If OK, measure resistance between “GRY/BLU” wire  terminal of temperature control actuator connector and 
“G51-3” terminal of HVAC control module connector.
Is resistance below 5 
Ω? Go to Step 5. “GRY/BLU” wire open or 
high resistance circuit.
5 Wire harness check
1) Measure resistance between “GRY/BLU” wire terminal 
of temperature control actuator connector and vehicle 
body ground.
Is resistance infinity? Go to Step 6.
“GRY/BLU” wire shorted 
to ground circuit.
6 Wire harness check
1) Measure voltage between “GRY/BLU” wire terminal of 
temperature control actuator  connector and vehicle body 
ground with ignition switch turned ON.
Is voltage 0 V? Go to Step 7.
“GRY/BLU” wire shorted 
to other circuit.  
Page 1007 of 1496
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7Wire harness check
1) Connect connector to HVAC  control module with ignition 
switch turned OFF.
2) Measure voltage between “GRY/RED” wire terminal of  temperature control actuator  connector and vehicle body 
ground with ignition switch turned ON when temperature 
selector is operation to HOT direction.
Is voltage 10 – 14 V? Go to Step 11. Go to Step 8.
8 Wire harness check
1) Disconnect connector from HVAC control module with 
ignition switch turned OFF.
2) Check for proper connection to HVAC control module  connector at “G51-3” and “G51-4” terminals.
3) If OK, measure resistance between “GRY/RED” wire  terminal of temperature control actuator connector and 
“G51-4” terminal of HVAC control module connector.
Is resistance below 5 
Ω? Go to Step 9. “GRY/RED” wire open 
or high resistance 
circuit.
9 Wire harness check
1) Measure resistance between “GRY/RED” wire terminal 
of temperature control actuator connector and vehicle 
body ground.
Is resistance infinity? Go to Step 10. “GRY/RED” wire 
shorted to ground 
circuit.
10 Wire harness check
1) Measure voltage between “GRY/RED” wire terminal of 
temperature control actuator  connector and vehicle body 
ground with ignition switch turned ON.
Is voltage 0 V? Go to Step 11. “GRY/RED” wire 
shorted to other circuit.
11 Position sensor circuit check
1) Check temperature control actuator position sensor 
circuit referring to Step 1 to Step 5 and Step 10 to Step 
11 of “DTC B1511: Temperature Control Actuator 
(Position Sensor) and/or Its Circuit Malfunction”.
Is it in good condition? Go to Step 12. Repair circuit.
12 Temperature control actuator check
1) Check temperature control actuator referring to 
“Temperature Control Actuator Inspection”.
Is it in good condition? HVAC control module 
faulty.
Temperature control 
actuator faulty.
Step Action Yes No  
Page 1008 of 1496
Downloaded from www.Manualslib.com manuals search engine 7B-60 Air Conditioning System: Automatic Type
DTC B1514: Air Flow Control Actuator and/or Its Circuit MalfunctionS7RS0B7224016
Wiring Diagram
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
NOTE
• When DTC B1502, B1503 and B1513 are indicated together, it is possible that “ORN” wire circuit open.
• When DTC B1513 is indicated together, it is possible that “WHT” wire circuit open.
 
7812910
65 431516 14 13 12 11
G52
789101920121112
65 431718 16 15 14 13
G51
M 12V
5V 5V
WHT/BLU
WHT
BRN/WHT
BRN/YEL
2
1
ORN
G51-1
G51-2
G52-1
G52-14
G52-3
3
4
I5RS0A722014-01
1. HVAC control module 2. Air flow control actuator3. To temperature control actuator 4. To other sensors
DTC Detecting Condition Trouble Area
Difference between target opening and actual opening is higher than 
specified value even though air flow  control actuator has operated for 16 
seconds. • Air flow control actuator circuit
• Air flow control linkage
• Air flow control actuator
• HVAC unit
• HVAC control module
Step
Action YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned 
OFF.
2) Turn ON ignition switch and check DTC.
Is there DTC B1512? Go to applicable DTC 
diag. flow.
Go to Step 2.
2 Visual check
1) Check if there is any obstruction in operating range of 
actuator linkage and if  actuator linkage operates 
smoothly.
Is it in good condition? Go to Step 3.
Obstruction in operating 
range of actuator 
linkage, actuator linkage 
faulty and/or internal 
fault of HVAC unit.
3 Wire harness check
1) Disconnect connector from air flow control actuator with 
ignition switch turned OFF.
2) Check for proper connection to  air flow control actuator 
connector at “BRN/WHT” and  “BRN/YEL” wire terminals.
3) If OK, measure voltage between “BRN/WHT” wire  terminal of air flow control actuator connector and 
vehicle body ground with ignition switch turned ON when 
air flow selector is operation to DEF direction.
Is voltage 10 – 14 V? Go to Step 7.
Go to Step 4.  
Page 1009 of 1496
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4Wire harness check
1) Disconnect connector from HVAC control module with 
ignition switch turned OFF.
2) Check for proper connection to HVAC control module  connector at “G51-1” and “G51-2” terminals.
3) If OK, measure resistance between “BRN/WHT” wire  terminal of air flow contro l actuator connector and “G51-
1” terminal of HVAC control module connector.
Is resistance below 5 
Ω? Go to Step 5. “BRN/WHT” wire open 
or high resistance 
circuit.
5 Wire harness check
1) Measure resistance between “BRN/WHT” wire terminal 
of air flow control actuator connector and vehicle body 
ground.
Is resistance infinity? Go to Step 6.
“BRN/WHT” wire 
shorted to ground 
circuit.
6 Wire harness check
1) Measure voltage between “BRN/WHT” wire terminal of 
air flow control actuator  connector and vehicle body 
ground with ignition switch turned ON.
Is voltage 0 V? Go to Step 7.
“BRN/WHT” wire 
shorted to other circuit.
7 Wire harness check
1) Connect connector to HVAC  control module with ignition 
switch turned OFF.
2) Measure voltage between “BRN/YEL” wire terminal of air  flow control actuator connector and vehicle body ground 
with ignition switch turned ON when air flow selector is 
operation to FACE direction.
Is voltage 10 – 14 V? Go to Step 11. Go to Step 8.
8 Wire harness check
1) Disconnect connector from HVAC control module with 
ignition switch turned OFF.
2) Check for proper connection to HVAC control module  connector at “G51-1” and “G51-2” terminals.
3) If OK, measure resistance between “BRN/YEL” wire  terminal of air flow contro l actuator connector and “G51-
2” terminal of HVAC control module connector.
Is resistance below 5 
Ω? Go to Step 9. “BRN/YEL” wire open or 
high resistance circuit.
9 Wire harness check
1) Measure resistance between “BRN/YEL” wire terminal of 
air flow control actuator  connector and vehicle body 
ground.
Is resistance infinity? Go to Step 10. “BRN/YEL” wire shorted 
to ground circuit.
10 Wire harness check
1) Measure voltage between “BRN/YEL” wire terminal of air 
flow control actuator connector and vehicle body ground 
with ignition switch turned ON.
Is voltage 0 V? Go to Step 11. “BRN/YEL” wire shorted 
to other circuit.
Step Action Yes No  
Page 1010 of 1496
Downloaded from www.Manualslib.com manuals search engine 7B-62 Air Conditioning System: Automatic Type
DTC B1541: HVAC Control Module Back-Up Power Supply MalfunctionS7RS0B7224017
Wiring Diagram
DTC Detecting Condition and Trouble Area
DTC Troubleshooting11
Position sensor circuit check
1) Check air flow control actuator position sensor circuit 
referring to Step 1 to Step 5 and Step 10 to Step 11 of 
“DTC B1512: Air flow Control  Actuator (Position Sensor) 
and/or Its Circuit Malfunction”.
Is it in good condition? Go to Step 12. Repair circuit.
12 Air flow control actuator check
1) Check air flow control actuator referring to “Air Flow 
Control Actuator Inspection”.
Is it in good condition? HVAC control module 
faulty.
Air flow control actuator 
faulty.
Step Action Yes No
WHT/RED
2 17812910
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G51
3
G52-16
I5RS0A722015-01
1. HVAC control module
2. Junction block assembly 3. Circuit fuse
DTC Detecting Condition Trouble Area
Back-up power supply voltage is lo wer than specified value continuously. • Battery voltage supply circuit
• HVAC control module
StepAction YesNo
1 DTC check
1) Turn ON ignition switch  for 20 sec. or more.
2) Ignition switch turned OF F and connect scan tool to 
DLC.
3) Turn ON ignition switch and check DTC.
Is there DTC B1541? Go to Step 2.
Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.
2 Battery voltage supply circuit check
1) Disconnect connector from HVAC control module with 
ignition switch turned OFF.
2) Check for proper connection to HVAC control module  connector at “G52-16” terminal.
3) If OK, measure voltage between “G52-16” terminal of  HVAC control module connector and vehicle body 
ground.
Is voltage 10 – 14 V? HVAC control module 
faulty.
Circuit fuse blown and/
or “WHT/RED” wire 
circuit open or short.  
Page 1012 of 1496
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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  
Page 1016 of 1496
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