Sunload sensor malfunction SUZUKI SX4 2006 1.G Service Workshop Manual

Downloaded from www.Manualslib.com manuals search engine 7-ii Table of Contents
Compressor Drive Belt Removal and
Installation ....................................................... 7B-31
Compressor Assembly Removal and
Installation ....................................................... 7B-31
Compressor Assembly Components................. 7B-32
Magnet Clutch Inspection.................................. 7B-32
Magnet Clutch Removal and Installation........... 7B-33
Thermal Switch Inspection ................................ 7B-35
Thermal Switch Removal and Installation ......... 7B-35
Relief Valve Inspection...................................... 7B-36
Relief valve Removal and Installation ............... 7B-36
Specifications .....................................................7B-37
Tightening Torque Specifications ...................... 7B-37
Special Tools and Equipment ...........................7B-37
Recommended Service Material ....................... 7B-37
Special Tool ...................................................... 7B-37
Automatic Type .....................................................7B-38
Precautions.........................................................7B-38
A/C System Caution .......................................... 7B-38
Precautions in Diagnosing Trouble ................... 7B-38
Precautions on Servicing A/C System .............. 7B-38
General Description ...........................................7B-39
Auto A/C System Description ............................ 7B-39
HVAC Control Description................................. 7B-40
Sub-Cool A/C System Description .................... 7B-40
On-Board Diagnostic System Description ......... 7B-41
Schematic and Routing Diagram ......................7B-41
A/C System Air Flow Diagram........................... 7B-41
A/C System Wiring Diagram ............................. 7B-42
Component Location .........................................7B-43
A/C System Major Components Location ......... 7B-43
Electronic Control System Components
Location .......................................................... 7B-44
Diagnostic Information and Procedures ..........7B-45
Air Conditioning System Check......................... 7B-45
A/C System Symptom Diagnosis ...................... 7B-47
Abnormal Noise Symptom Diagnosis of A/C
System ............................................................ 7B-49
DTC Check........................................................ 7B-49
DTC Clearance ................................................. 7B-51
DTC Table ......................................................... 7B-52
Fail-Safe Table .................................................. 7B-54
Scan Tool Data ................................................. 7B-55
Visual Inspection ............................................... 7B-57
DTC B1502: Inside Air Temperature Sensor
Circuit Malfunction .......................................... 7B-57
DTC B1503: Evaporator Temperature Sensor
Circuit Malfunction .......................................... 7B-59
DTC B1504: Sunload Sensor Circuit
Malfunction ...................................................... 7B-60
DTC B1511: Temperature Control Actuator
(Position Sensor) and/or Its Circuit
Malfunction ...................................................... 7B-61
DTC B1512: Air flow Control Actuator
(Position Sensor) and/or Its Circuit
Malfunction ...................................................... 7B-63
DTC B1513: Temperature Control Actuator
(Motor) and/or Its Circuit Malfunction .............. 7B-65DTC B1514: Air Flow Control Actuator (Motor)
and/or Its Circuit Malfunction........................... 7B-67
DTC B1520 / B1521 / B1522: Temperature /
Blower Speed / Air Flow Selector
Malfunction ...................................................... 7B-68
DTC B1541: Back-Up Power Supply Circuit
Malfunction ...................................................... 7B-69
DTC B1546: A/C Refrigerant Pressure
Malfunction ...................................................... 7B-70
DTC B1551: Serial Communication Circuit
Malfunction ...................................................... 7B-70
DTC B1552: HVAC Control Module Check
Sum Error ........................................................ 7B-72
DTC B1553: CAN Communication Circuit
Malfunction ...................................................... 7B-72
DTC B1557: VSS Signal Failure ....................... 7B-73
DTC B1561: ECT Signal Failure ....................... 7B-73
DTC B1562: Outside Air Temperature Signal
Failure ............................................................. 7B-74
DTC B1563: A/C Refrigerant Pressure Signal
Failure ............................................................. 7B-74
DTC B1570: Engine Type Signal Failure .......... 7B-75
DTC B1571: Combination Meter Spec Signal
Failure ............................................................. 7B-75
Inspection of HVAC Control Module and Its
Circuit .............................................................. 7B-76
A/C System Inspection at ECM ......................... 7B-79
Repair Instructions ............................................7B-79
Operation Procedure for Refrigerant Charge .... 7B-79
HVAC Unit Components ................................... 7B-80
HVAC Unit Removal and Installation ................ 7B-81
Temperature Control Actuator Removal and
Installation ....................................................... 7B-81
Temperature Control Actuator and Its Circuit
Inspection ........................................................ 7B-81
Air Flow Control Actuator Removal and
Installation ....................................................... 7B-83
Air Flow Control Actuator and Its Circuit
Inspection ........................................................ 7B-83
Air Intake Actuator Removal and Installation .... 7B-84
Air Intake Actuator Inspection ........................... 7B-84
Actuator Linkage Inspection.............................. 7B-84
Blower Motor Controller Removal and
Installation ....................................................... 7B-84
Blower Motor Controller Inspection ................... 7B-85
HVAC Control Module Removal and
Installation ....................................................... 7B-85
Sunload Sensor Removal and Installation ........ 7B-85
Sunload Sensor Inspection ............................... 7B-86
Outside Air Temperature Sensor Removal
and Installation ................................................ 7B-86
Outside Air Temperature Sensor Inspection ..... 7B-86
Inside Air Temperature Sensor Removal and
Installation ....................................................... 7B-86
Inside Air Temperature Sensor Inspection ........ 7B-86
Condenser Cooling Fan Relay Inspection......... 7B-87
Condenser Cooling Fan Removal and
Installation ....................................................... 7B-87
Condenser Cooling Fan Inspection ................... 7B-87
Condenser Assembly On-Vehicle Inspection .... 7B-87

Downloaded from www.Manualslib.com manuals search engine 7B-40 Air Conditioning System: Automatic Type
HVAC Control DescriptionS6RW0D7221002
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, ECT 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, ECT 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 air flow control
actuator so that the current air flow control 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)A/C Compressor Relay Control
HVAC control module outputs A/C switch ON signal to
ECM via BCM when the vehicle state satisfy conditions
described below.
• A/C switch is ON
• Evaporator temperature is higher than specified value
• Evaporator temperature sensor malfunction is not
detected
Communication of ECM and BCM is established by CAN
(Controller Area Network). (For more detail of CAN
communication, refer to “CAN Communication System
Description in Section 1A”).
ECM turns ON the A/C compressor relay when the
vehicle state satisfy conditions described below.
• A/C switch ON signal is inputted
• A/C refrigerant pressure is within specified range
• Engine speed is within specified range
• Engine coolant temperature is lower than specified
value
• Throttle opening is lower than specified value
• Vehicle is not in either state of starting or quick
acceleration
• ECT sensor malfunction is not detected
• A/C refrigerant pressure sensor malfunction is not
detected
Condenser Cooling Fan Relay Control
ECM turn ON the condenser cooling fan relay at the
same time when ECM turn ON the A/C compressor
relay.
Sub-Cool A/C System DescriptionS6RW0D7221003
Refer to “Sub-Cool A/C System Description”.

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On-Board Diagnostic System DescriptionS6RW0D7221004
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 detects malfunctions, which may
occur in the following area.
• Inside air temperature sensor
• Evaporator temperature sensor
• Sunload sensor
• Temperature control actuator
• Air flow control actuator
• Temperature selector of HVAC control module
• Air flow selector of HVAC control module
• Blower speed selector of HVAC control module
• Back-up power supply circuit of HAVC control module
• Serial communication line between BCM and HVAC
control module• Received data from BCM as follows
– Outside air temperature sensor signal
– ECT sensor signal
– A/C refrigerant pressure sensor signal
– VSS signal
– Engine type signal
– Combination meter spec signal
– CAN communication circuit failure signal
When HVAC control module detects malfunction, the “A/
C” indicator light (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
A/C System Air Flow DiagramS6RW0D7222001
Refer to “A/C System Air Flow Diagram”.
1
I5RW0A722002-01

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Abnormal Noise Symptom Diagnosis of A/C
System
S6RW0D7224003
Refer to “Abnormal Noise Symptom Diagnosis of A/C
System”.
DTC CheckS6RW0D7224004
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 tool3) Light over sunload sensor vertically with an
incandescent light of approximately 100 W apart
from about 100 mm (3.94 in.).
NOTE
If sunload sensor is not lighted over with an
incandescent light, DTC B1504 is detected
even though there is not any malfunction.

4) Turn ignition switch to ON position.
5) Read DTC 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 check, turn ignition switch to
OFF position and disconnect SUZUKI scan tool from
data link connector (DLC). Insufficient air flow of
cooled airA/C evaporator clogged or frostedCheck A/C evaporator and evaporator
temperature sensor referring to “Evaporator
Inspection” and “Evaporator Temperature
Sensor Inspection”.
Air leaking from HVAC unit or air ductRepair as necessary.
Blower motor faultyCheck blower motor referring to “Blower Motor
Inspection in Section 7A”.
Wiring or grounding faultyRepair as necessary. Condition Possible cause Correction / Reference Item(A)
1I5RW0A722004-01

Downloaded from www.Manualslib.com manuals search engine 7B-50 Air Conditioning System: Automatic Type
Not Using SUZUKI Scan Tool
NOTE
In case of malfunction of temperature
selector, blower speed selector and air flow
selector, DTC can not be checked by the
following procedure. Use SUZUKI scan tool
for DTC check.

1) Light over sunload sensor vertically with an
incandescent light of approximately 100 W apart
from about 100 mm (3.94 in.).
NOTE
If sunload sensor is not lighted over with an
incandescent light, DTC of sunload sensor is
detected as current DTC even though there is
not any malfunction.

2) Set the following selectors to specified positions
below respectively with ignition switch off position.
• Temperature selector (1) is maximum cool
position
• Blower speed selector (2) is OFF position
• Air flow selector (3) is AUTO position
3) While pressing A/C switch (4) and air intake selector
(5) simultaneously, turn ignition switch to ON
position.
4) Wait for about 5 seconds (start of diagnosis).
5) Read flashing pattern of “FRE” (6) and “REC” (7)
indicator lights which represents DTC and write it
down.
NOTE
• When 2 or more current 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.
• Pressing “A/C” switch alternates display
of current DTC and history DTC. “A/C”
indicator light (8) remains off when display
is in current DTC mode and it lights up
when display is in history DTC mode.
• When a history DTC is indicated while 2 or
more history DTCs are detected, it is
possible to have other history DTC(s)
stored in HVAC control module displayed
by pressing the air intake selector.

Example: When inside air temperature sensor
circuit malfunction (Open) is set
Example: When VSS signal failure (Data error) is
set
6) After completing above check, turn ignition switch to
“OFF” position.
[A]: “REC” indicator light L: OFF
[B]: “FRE” indicator light a. About 0.5 seconds
H: ON b. About 2 seconds
[A]: “REC” indicator light a. About 0.5 seconds
[B]: “FRE” indicator light b. About 3 seconds
H: ON c. About 1.5 seconds
L: OFF
123
458
6
7I5RW0A722005-01
[A]
[B]H
L
H
L [B]
[A]
ab
aI5RW0A722006-02
[A]
[B]H
L
H
L [B]
[A]
ab
aaaa
c
I5RW0A722025-01

Downloaded from www.Manualslib.com manuals search engine 7B-54 Air Conditioning System: Automatic Type
DTC of A/C System detected by ECM
NOTE
When no DTC is detected, “FRE” [A] and “REC” [B] indicator lights on HVAC control module flash at
the same time in specific pattern.

Fail-Safe TableS6RW0D7224007
When any of the following malfunctions (DTCs) is detected, fail-safe mode is activated.
However, when HVAC control module detects normal operation of A/C system, fail-safe mode is canceled. DTC No. Detection itemDetecting condition
(DTC will set when detecting)MIL
P0481 Fan 2 Control Circuit
Refer to “Fail-Safe Table in Section 1A”. P0532A/C Refrigerant Pressure
Sensor Circuit Low
P0533A/C Refrigerant Pressure
Sensor Circuit High
H: ON a. About 3 seconds
L: OFF b. About 1 seconds
DTC No. Trouble AreaFail-Safe Operation
When ignition switch is turned ON
after malfunction is already detectedWhen malfunction is detected during
ignition switch is ON
) B1502Inside air temperature
sensor circuitHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that inside air temperature is
25 °C (77 °F).
) B1503A/C evaporator
temperature sensor
circuitHVAC control module assuming that
evaporator temperature is 0 °C (32 °F).• HVAC control module turns off A/C
switch signal.
• HVAC control module controls
actuators assuming that evaporator
temperature is 0 °C (32 °F).
) B1504 Sunload sensor circuitHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that amount of sunlight is 0 W/
m
2.
) B1520Temperature selector
malfunctionHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that setting of temperature
selector is 25 °C (77 °F) position.
) B1521Blower speed selector
malfunctionHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that setting of blower speed
selector is low (1st) position.
) B1522Air flow selector
malfunctionHVAC control module maintains last
normal value.HVAC control module controls actuators
assuming that setting of air flow selector
is DEF position.
[A]
[A]H
L
H
L [B]
[B]
baaba
baaba
I5RW0A722008-01

Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-57
SUN LOAD (W/m2): This parameter indicates the
amount of sunlight detected by sunload sensor.
MODE CONT SWITCH (Air flow selector position,
AUTO, FACE, B/L, FOOT, D/F, DEF): This
parameter indicates the selected position of air flow
selector.
FAN CONT SWITCH (Blower speed selector, AUTO,
OFF, 1st – 8th): This parameter indicates the
selected position of blower speed selector.
FAN DESIRE VOLT (Fan desired voltage, V): This
parameter indicates the consumption voltage of
blower motor.
AIR MIX POS SENSOR (Temperature control
actuator position sensor, V): This parameter
indicates the input signal from position sensor in
temperature control actuator.
MODE POS SENSOR (Air flow control actuator
position sensor, V): This parameter indicates the
input signal from position sensor in air flow control
actuator.
A/C CONT SIG (A/C control signal, ON, OFF): This
parameter indicates the state of A/C switch.BLOWER LOAD SIG (Blower fan load signal, ON,
OFF): ON: Position of blower speed selector is 1st
position or more.
OFF: Position of blower speed selector is OFF
position.
AIR INTAKE MODE (Air intake selector position,
AUTO, FRE, REC): This parameter indicates the
selected position of air intake selector.
REFRIGERANT PRESSURE (A/C refrigerant absolute
pressure, kPa): This parameter indicates the A/C
refrigerant absolute pressure calculated by ECM
A/C COMP CLUCH (A/C compressor magnet clutch,
ON, OFF): This parameter indicates the state of the
A/C compressor magnet clutch.
VEHICLE SPEED (km/h, mph): This parameter
indicates the vehicle speed calculated by ECM.
ENGINE TYPE (Engine type signal, J20, M16 or
M15): This parameter indicates the engine type
signal transmitted by ECM.
METER SPEC (Combination meter spec signal, EU,
UK, US, Canada, DOM): This parameter indicates
the combination meter spec signal transmitted by
combination meter.
Visual InspectionS6RW0D7224009
Check visually the following parts and systems.
DTC B1502: Inside Air Temperature Sensor Circuit MalfunctionS6RW0D7224010
Wiring DiagramInspection item Correction
• Refrigerant leakage and amount
• A/C pipe or hose disconnection,
looseness and
deterioration
• A/C compressor drive belt looseness and damageRefer to “Compressor Drive Belt Inspection
and Adjustment”.
• Battery fluid level and corrosion
of terminal
• Connectors of electric wire harness disconnection and
friction
• Fuses burning
• Parts installation and damage
• Other parts that can be checked visually
5V
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
ORNORNPNK/BLKG20-10
21
3 [S]
[G]
G20-24
I7RW01722004-01
[S]: Inside air temperature sensor signal circuit 1. HVAC control module 3. To other sensors
[G]: Inside air temperature sensor ground circuit 2. Inside air temperature sensor

Downloaded from www.Manualslib.com manuals search engine 7B-60 Air Conditioning System: Automatic Type
DTC B1504: Sunload Sensor Circuit MalfunctionS6RW0D7224012
Wiring Diagram
DTC Detecting Condition and Trouble Area
NOTE
When DTC B1502, B1503, B1511 and B1512 are indicated together, it is possible that sensor ground
circuit is open.

3Evaporator temperature sensor reference voltage check
1) Connect connector to HVAC control module with ignition
switch turned OFF.
2) Turn ignition switch to ON position.
3) Measure voltage between signal terminal and ground
terminal of evaporator temperature sensor connector.
Is voltage 4.5 – 5.5 V?Go to Step 4. Substitute a known-
good HVAC control
module and recheck.
4Evaporator temperature sensor check
1) Check evaporator temperature sensor for performance
referring to “Evaporator Temperature Sensor
Inspection”.
Is it in good condition?Substitute a known-
good HVAC control
module and recheck.Replace evaporator
temperature sensor. Step Action Yes No
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
PNK
ORNORN
G20-25
G20-24
2
[S]
[G]15V
3
I7RW01722006-01
[S]: Sunload sensor signal circuit 1. HVAC control module 3. To other sensors
[G]: Sunload sensor ground circuit 2. Sunload sensor
DTC Detecting Condition Trouble Area
• Sunload sensor signal voltage is higher than or lower than specified value
for specified time continuously.
• Without sunlight• Sunload sensor circuit
• Sunload sensor
• HVAC control module

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DTC Troubleshooting
DTC B1511: Temperature Control Actuator (Position Sensor) and/or Its Circuit MalfunctionS6RW0D7224013
Wiring DiagramStep Action Yes No
1Was “Air Conditioning System Check” performed?Go to Step 2. Go to “Air Conditioning
System Check”.
2Wire harness check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from sunload sensor and HVAC
control module.
3) Check for proper connection to each signal circuit
terminal and ground circuit terminal of sunload sensor
and HVAC control module connectors.
4) If OK, check that sunload sensor circuit is as follows.
• Wiring harness resistance of each sunload sensor
signal circuit and ground circuit is less than 3 Ω
• Insulation resistance of each sunload sensor signal
circuit and ground circuit between sunload sensor
connector and vehicle body ground is Infinity
• Circuit voltage of each sunload sensor signal circuit
and ground circuit is 0 – 1 V with ignition switch turned
ON
Are they in good condition?Go to Step 3. Sunload sensor power
supply circuit and/or
signal circuit are open,
short or high resistance.
3Sunload sensor power supply voltage check
1) Connect connector to HVAC control module with ignition
switch turned OFF.
2) Turn ignition switch to ON position.
3) Measure voltage between signal terminal and ground
terminal of sunload sensor connector.
Is voltage 4.5 – 5.5 V?Go to Step 4. Substitute a known-
good HVAC control
module and recheck.
4Sunload sensor check
1) Check sunload sensor for performance referring to
“Sunload Sensor Inspection”.
Is it in good condition?Substitute a known-
good HVAC control
module and recheck.Replace sunload
sensor.
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
GRY/BLUGRY/RED
5V5V
12V
ORN
WHT
YEL
G20-12
G20-27
G20-24
G20-1G20-2
2
[P]
[S]3
4
[G]
1
I6RW0C722004-01
[P]: Position sensor power supply circuit [G]: Position sensor ground circuit 2. Temperature control actuator 4. To other sensors
[S]: Position sensor signal circuit 1. HVAC control module 3. To air flow control actuator