Ac control SUZUKI SWIFT 2005 2.G Service Workshop Manual

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
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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.

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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
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G51-7
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G37-11
I5RS0A722016-01
1. HVAC control module 2. BCM3. Information display

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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

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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.

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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.

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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.

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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”

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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

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Terminal Wire Color CircuitNormal
Vo l ta g e Condition
G52-1 WHT Output of 5 V power
source for air flow control
actuator position sensor
and temperature control
actuator position sensor 4 – 6 V Ignition switch turned ON
G52-2 PNK Output of 5 V power
source for sunload sensor 4 – 6 V Ignition switch turned ON
G52-3 ORN Ground for sensors Below 0.3 V Ignition switch turned ON
G52-4 WHT/BLK Evaporator temperature
sensor signal 3.45 – 3.65 V
Ignition switch turned ON, evaporator temperature 0
°
C (32 °F)
2.55 – 2.85 V Ignition switch turned ON, evaporator temperature
15
°C (59 ° F)
1.7 – 2.1 V Ignition switch turned ON, evaporator temperature
30
°C (86 ° F)
G52-5 YEL/BLK Sunload sensor signal
G52-6 PNK/BLK Inside air temperature
sensor signal About 2.0 V
Ignition switch turned ON, room temperature 25
°C
(77 °F)
About 2.8 V Ignition switch turned ON, room temperature 0
°C
(32 °F)
G52-7 — — — —
G52-8 RED/BLK Electric power source 10 – 14 V Ignition switch turned ON
G52-9 — — — —
G52-10 — — — —
G52-11 BLK/ORN Ground for HVAC control
module Below 0.3 V Ignition
switch turned ON
G52-12 — — — —
G52-13 YEL Temperature control
actuator position sensor
signal About 4.0 V
Ignition switch turned ON, temperature selector MAX
COOL position
About 2.0 V Ignition switch turned ON, temperature selector MAX
HOT position
G52-14 WHT/BLU Air flow control actuator
position sensor signal About 4.0 V
Ignition switch turned ON
, air flow selector VENT
position
About 1.6 V Ignition switch ON, air flow selector DEF position
G52-15 — — — —
G52-16 WHT/RED Electric power source for
back-up 10 – 14 V Full-time

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ECM Voltage Values Table for Relation of A/C Control
Repair Instructions
Operation Procedure for Refrigerant ChargeS7RS0B7226001
Refer to “Operation Procedure for Refrigerant Charge”.Terminal Wire Color Circuit Normal Value Condition
C37-14 GRY/RED Output of 5 V power
source 4.5 – 5.5 V Ignition switch turned ON
C37-15 BLK Ground for ECM Below 0.3 V Ignition switch turned ON
C37-24 LT GRN Engine coolant temp.
(ETC) sensor signal 3.3 – 3.8 V Ignition switch turned ON, ECT at 0
°C (32 ° F)
1.38 – 1.72 V Ignition switch turned ON, ECT at 50 °C (122 °F)
C37-30 BLK Ground for ECM Below 0.3 V Ignition switch turned ON
C37-55 ORN Ground for sensors Below 0.3 V Ignition switch turned ON
C37-58 BLK/ORN Ground for ECM Below 0.3 V Ignition switch turned ON E23-1 BLK/RED Main power supply 10 – 14 V Ignition switch turned ON
E23-3 RED CAN (high)
communication line
(active high signal)
for BCM and
combination meterRefer to “DTC P2101: Throttle Actu
ator Control Motor Circuit Range /
Performance in Section 1A”
E23-16 BLK/RED Main power supply 10 – 14 V Ignition switch turned ON
E23-18 WHT CAN (low)
communication line
(active low signal) for
BCM and
combination meterRefer to “DTC P2101: Throttle Actu
ator Control Motor Circuit Range /
Performance in Section 1A”
E23-19 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 – 1 V Ignition switch turned ON, blower speed selector
between 6th and HIGH position
E23-46 LT GRN Radiator fan relay
No.1 output 10 – 14 V
Ignition switch turned ON, engine coolant temp.:
below 95
°C (203 ° F), or A/C refrigerant pressure:
below 600 kPa (87 psi).
0 – 2 V Ignition switch turned ON, engine coolant temp.:
97.5
°C (207.5 °F) or higher, or A/C refrigerant
pressure: 1100 kPa (159.5 psi) or higher.
E23-47 GRY A/C compressor relay
output 10 – 14 V Engine running, A/C request signal high input
0 – 1 V Engine running, A/C request signal low input
E23-48 GRN Radiator fan relay
No.2 and No.3 output 10 – 14 V
Ignition switch turned ON, engine coolant temp.:
below 100
°C (212 °F), or A/C refrigerant
pressure: below 1200 kPa (174 psi).
0 – 2 V Ignition switch turned ON, engine coolant temp.:
102.5
°C (216.5 ° F) or higher, or A/C refrigerant
pressure: 1500 kPa (217.5 psi) or higher.
E23-55 RED A/C refrigerant
pressure sensor
signal 1.46 – 1.71 V
Engine running, A/C refrigerant pressure at 0.8
MPa (8.0 kg/cm
2) (A/C refrigerant pressure
measured by manifold gauge)
2.55 – 2.80 V Engine running, A/C refrigerant pressure at 1.6
MPa (16.0 kg/cm
2) (A/C refrigerant pressure
measured by manifold gauge)
E23-60 BRN/WHT Main power supply
relay output 10 – 14 V Ignition switch turned OFF
0 – 2 V Ignition switch turned ON

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HVAC Unit ComponentsS7RS0B7226002
NOTE
The figure shows left-hand steering vehicle. For right-hand steering vehicle, parts with (*) are installed
at the opposite side.

10 * 2 *
6
7
1 *
4 *
2 *
5
7
8
8
17
16
18
19
6
12
11 *
21 *
20
20
22
9 *
13
3 *
5
15 *
14 *
15 *
23 *
24 *
25 *
26 *
I5RS0C722003-01
1. Fresh air inlet duct
8. Temperature control door assembly 15. Air flow control links 22. Drain hose