2006 SUZUKI SX4 Service Workshop Manual

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-69
DTC B1541: Back-Up Power Supply Circuit MalfunctionS6RW0D7224018
Wiring Diagram
DTC Detecting Condition and Trouble Area
NOTE
When checking DTC after connecting battery cable, be sure to turn ignition switch from OFF to ON and
from ON to OFF at least once, or DTC B1541 will be detected.

DTC Troubleshooting
12V5V
WHTG20-7 2
31G201 2 3 4 5 6 7 8 9 10 11 12 13 14
15 16 17 18 19 20 21 24 23 22 25 26 27 28 29 30WHT/RED [B]
I7RW01722011-01
[B]: Back-up power supply circuit 2. Main fuse
1. HVAC control module 3. Circuit fuse
DTC Detecting Condition Trouble Area
• Back-up power supply voltage is lower than specified value continuously.
• When connect battery with vehicle and then, turn ignition switch to ON
position for first time.• Battery voltage supply circuit
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2DTC check
1) Turn ignition switch to ON position for 20 sec. or more.
2) Ignition switch turned OFF and connect scan tool to
DLC.
3) Turn ON ignition switch and check DTC.
Is there DTC B1541?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
3Battery voltage supply circuit check
1) Disconnect connector from HVAC control module with
ignition switch turned OFF.
2) Check for proper connection to back-up power supply
circuit terminal of HVAC control module connector.
3) If OK, measure voltage between back-up power supply
circuit terminal of HVAC control module connector and
vehicle body ground.
Is voltage 10 – 14 V?Substitute a known-
good HVAC control
module and recheck.Back-up power supply
circuit is open or
shorted to ground.

Downloaded from www.Manualslib.com manuals search engine 7B-70 Air Conditioning System: Automatic Type
DTC B1546: A/C Refrigerant Pressure MalfunctionS6RW0D7224019
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1551: Serial Communication Circuit MalfunctionS6RW0D7224020
Wiring DiagramDTC detecting condition Trouble area
• A/C refrigerant pressure sensor signal voltage is lower than specified value
even though outside air temperature is higher than specified value for
specified time continuously.
• Insufficient refrigerant in A/C system• Insufficient of refrigerant
• A/C refrigerant pressure sensor
• Outside air temperature sensor
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ignition switch to ON position and check DTC in
BCM.
Is DTC B1141 or B1142 (BCM) detected?Go to applicable DTC
diag. flow.Go to Step 3.
3DTC check
Check DTC in ECM.
Is DTC P0532 or P0533 detected?Go to applicable DTC
diag. flow.Go to Step 4.
4A/C refrigerant pressure and outside air temperature
data check
1) Start engine and select “DATA LIST” mode on scan tool.
2) Check “Refrigerant Pressure” and “Outside Air Temp”
displayed on scan tool.
Are values of A/C refrigerant pressure sensor and outside air
temperature within specified ranges indicated in “Scan Tool
Data”?Substitute a known-
good HVAC control
module and recheck.Check the amount of
refrigerant and system
for leaks.
12V
G20
G20-13YEL
1 2 3 4 5 6 7 8 9 10 11 12 13 14
15 16 17 18 19 20 21 24 23 22 25 26 27 28 29 30
1
2 3
[S]WHT/REDWHTG20-7
12V5V
[B]4 4
I7RW01722012-02
[B]: Back-up power supply circuit 1. HVAC control module 3. Information display
[S]: Serial communication circuit 2. BCM 4. Circuit fuse

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-71
DTC Detecting Condition and Trouble Area
DTC TroubleshootingDTC detecting condition Trouble area
Serial communication signal is higher than or lower than specified value for
specified time continuously.• Back-up power supply circuit
• Serial communication circuit
•BCM
• Information display
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2Back-up power supply circuit fuse check
1) Check back-up power supply circuit fuse for blowing.
Is fuse(s) blown?Replace blown fuse and
check for short in back-
up power supply circuit.Go to Step 3.
3Wire harness check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from BCM, information display
and HVAC control module.
3) Check for proper connection to serial communication
circuit terminal of BCM, information display and HVAC
control module connectors.
4) If OK, check that serial communication circuit is as
follows.
• Wiring harness resistance of serial communication
circuit is less than 3 Ω
• Insulation resistance between serial communication
circuit terminal and vehicle body ground is Infinity
• Circuit voltage of serial communication circuit is 0 - 1
V with ignition switch turned ON
Are they in good condition?Go to Step 4. Serial communication
circuit is open, short or
high resistance.
4Serial communication signal check
1) Connect connectors to BCM and HVAC control module
with ignition switch turned OFF.
2) Turn ignition switch to ON position.
3) Check that serial communication signal is outputted from
BCM referring to “Voltage Check” under “Inspection of
BCM and Its Circuits in Section 10B”.
Is serial communication signal outputted?Replace information
display.Go to Step 5.
5Communication data check
1) Connect connector to information display with ignition
switch turned OFF.
2) Check that serial communication signal is outputted from
BCM referring to “Voltage Check” under “Inspection of
BCM and Its Circuits in Section 10B”.
Is serial communication signal outputted?Substitute a known-
good HVAC control
module and recheck.Substitute a known-
good BCM and recheck.

Downloaded from www.Manualslib.com manuals search engine 7B-72 Air Conditioning System: Automatic Type
DTC B1552: HVAC Control Module Check Sum ErrorS6RW0D7224021
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1553: CAN Communication Circuit MalfunctionS6RW0D7224022
DTC Detecting Condition and Trouble Area
DTC TroubleshootingDTC detecting condition Trouble area
Data received by HVAC control module from BCM is erroneous continuously. • BCM
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2Serial 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” displayed on scan tool.
Are values of A/C refrigerant pressure sensor and outside air
temperature within specified ranges indicated in “Scan Tool
Data”?Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”Substitute a known-
good HVAC control
module and recheck.
If DTC is still detected
substitute a known-
good BCM and recheck.
DTC detecting condition Trouble area
HVAC control module receives error code from BCM continuously. • CAN communication circuit
•BCM
•ECM
• Combination meter
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check DTC in BCM.
Is DTC U0073 (No.0073), U0100 (No.0100) and/or U0155
(No.0155) detected?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-73
DTC B1557: VSS Signal FailureS6RW0D7224023
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1561: ECT Signal FailureS6RW0D7224024
DTC Detecting Condition and Trouble Area
DTC TroubleshootingDTC detecting condition Trouble area
HVAC control module receives invalid data of VSS signal from BCM. • VSS circuit
• VSS
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check DTC in ECM.
Is DTC P0500 detected?Go to applicable DTC
diag flow.Substitute a known-
good HVAC control
module and recheck.
DTC detecting condition Trouble area
HVAC control module receives invalid data of ECT signal from BCM. • ECT sensor circuit
• ECT sensor
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check DTC in ECM.
Is DTC P0116, P0117 or P0118 detected?Go to applicable DTC
diag. flow.Substitute a known-
good HVAC control
module and recheck.

Downloaded from www.Manualslib.com manuals search engine 7B-74 Air Conditioning System: Automatic Type
DTC B1562: Outside Air Temperature Signal FailureS6RW0D7224025
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1563: A/C Refrigerant Pressure Signal FailureS6RW0D7224026
DTC Detecting Condition and Trouble Area
DTC TroubleshootingDTC detecting condition Trouble area
HVAC control module receives invalid data of outside air temperature signal
from BCM.• Outside air temperature sensor
circuit
• Outside air temperature sensor
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check DTC in BCM.
Is DTC B1141 or B1142 detected?Go to applicable DTC
diag. flow.Substitute a known-
good HVAC control
module and recheck.
DTC detecting condition Trouble area
HVAC control module receives invalid data of A/C refrigerant pressure signal
from BCM.• A/C refrigerant pressure sensor
circuit
• A/C refrigerant pressure sensor
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check DTC in ECM.
Is DTC P0532 or P0533 detected?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-75
DTC B1570: Engine Type Signal FailureS6RW0D7224027
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
DTC B1571: Combination Meter Spec Signal FailureS6RW0D7224028
DTC Detecting Condition and Trouble Area
DTC TroubleshootingDTC detecting condition Trouble area
HVAC control module receives invalid data of engine type signal from BCM. • CAN communication circuit
• HVAC control module
•ECM
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2Scan tool data check
1) Connect scan tool with ignition switch turned OFF
position.
2) Ignition switch turned ON and select “DATA LIST” mode.
3) Check “ENGINE TYPE” displayed on scan tool.
Is value of engine type signal within specified ranges
indicated in “Scan Tool Data”?Substitute a known
good HVAC control
module and recheck.Go to step 3.
3Scan tool data check
1) Check “ENGINE TYPE” displayed on scan tool.
Is “CAN Err” displayed on scan tool data?Check CAN
communication circuit
referring to “DTC Check
in Section 1A”.Substitute a known
good ECM and recheck.
DTC detecting condition Trouble area
HVAC control module receives invalid data of Combination meter spec signal
from BCM.• CAN communication circuit
• Combination meter
• HVAC control module
Step Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2Scan tool data check
1) Connect scan tool with ignition switch turned OFF
position.
2) Ignition switch turned ON and select “DATA LIST” mode.
3) Check “METER SPEC” displayed on scan tool.
Is value of combination meter spec signal within specified
ranges indicated in “Scan Tool Data”?Substitute a known
good HVAC control
module and recheck.Go to step 3.
3Scan tool data check
1) Check “METER SPEC” displayed on scan tool.
Is “CAN Err” displayed on scan tool data?Check CAN
communication circuit
referring to “DTC Check
in Section 1A”.Substitute a known
good combination meter
and recheck.

Downloaded from www.Manualslib.com manuals search engine 7B-76 Air Conditioning System: Automatic Type
Inspection of HVAC Control Module and Its CircuitS6RW0D7224029
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.

G20
1 2 3 4 5 6 7 8 9 10 11 12 13 14
15 16 17 18 19 20 21 24 23 22 25 26 27 28 29 30
12
I7RW01722013-01
1. HVAC control module 2. HVAC control module connector (viewed from harness side)
Terminal Wire Color CircuitNormal
Vo l ta g eCondition
G20-1 GRY/BLUTemperature control
actuator (COOL)10 – 14 VIgnition switch turned ON, temperature control
actuator is working in operation from HOT to COOL
position
0 – 2 VIgnition switch turned ON, except the above
condition
G20-2 GRY/REDTemperature control
actuator (HOT)10 – 14 VIgnition switch turned ON, temperature control
actuator is working in operation from COOL to HOT
position
0 – 2 VIgnition switch turned ON, except the above
condition
G20-3 BLUSerial communication line
of data link connector10 – 14 V Ignition switch turned ON
G20-4 GRN/YEL Rear defogger switchRefer to “Reference waveform No. 1: Automatic Type”.
G20-5 BLK/YEL Illumination ground 0 – 1 V Full-time
G20-6 RED/YEL Illumination switch0 – 1 VIgnition switch turned ON, lighting switch OFF
position
10 – 14 V Ignition switch turned ON, lighting switch ON position
G20-7 WHT/REDElectric power source for
back-up10 – 14 V Constantly