BCM SUZUKI SX4 2006 1.G Service Repair Manual

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3Communication check
1) Check DLC terminal for deformation and wear.
2) If it is in good condition, connect SUZUKI scan tool to
DLC with ignition switch tuned OFF.
3) Check if communication is possible by making
communication with other control modules (BCM, ABS,
HVAC control module or SDM).
Is it possible to communicate with the other control
modules?Go to Step 4. Go to Step 6.
4Serial communication circuit check
1) With ignition switch turned OFF, disconnect “E11”
connector from P/S control module and check for proper
connection at P/S control module connector terminal.
2) If connections are OK, check that “Serial data circuit” is
as follows.
• Wiring resistance of “Serial data circuit” wire between
DLC connector and P/S control module connector is
less than 1 Ω.
Is it resistance less than 1
Ω?Go to Step 5. “Serial data circuit” is
open or high resistance.
5P/S control module power and ground circuit check
1) Check power supply circuit and ground circuit for P/S
control module referring to “P/S Control Module Power
Supply and Ground Circuit Check”.
Is check result in good condition?Substitute a known-
good P/S control
module and recheck.Repair or replace
defective circuit.
6DLC power and ground circuit check
1) Check power supply circuit and ground circuit for DLC
connector as follows.
• Voltage of “DLC connector power supply circuit”
between DLC connector terminal and vehicle body
ground is 10 –14 V with ignition switch turned ON.
• Wire resistance of each “DLC connector ground
circuit” between DLC connector terminal and vehicle
body ground is less than 1 Ω.
Is check result in good condition?Go to Step 7. Repair or replace
defective circuit.
7Serial communication circuit check
1) With ignition switch turned OFF, disconnect “E11”
connector from P/S control module and check for
terminal to P/S control module connector.
2) If connections are OK, check that “Serial data circuit” is
as follows.
• Insulation resistance of “Serial data circuit” wire is
infinity between its terminal and other terminals at P/S
control module connector.
• Insulation resistance of “Serial data circuit” wire is
infinity between its terminal and vehicle body ground.
Is circuit in good condition?Go to Step 8. Repair or replace
defective circuit. Step Action Yes No

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DTC C1121 / C1123 / C1124: Vehicle Speed Signal Circuit FailureS6RW0D6304014
DTC C1121: No Vehicle Speed Signal (60 Seconds or More)
DTC C1123: No Vehicle Speed Signal (30 Seconds or More)
DTC C1124: Vehicle Speed Performance (Impossible Deceleration)
Wiring Diagram5Torque sensor power supply circuit check
1) Check that torque sensor power supply circuit is as
follows.
• Insulation resistance of wire harness is infinity
between “Torque sensor power supply circuit” terminal
and each other terminal at torque sensor connector.
• Wiring harness resistance of “Torque sensor power
supply circuit” is less than 1 Ω.
• Insulation between “Torque sensor power supply
circuit” and vehicle body ground is infinity.
Is circuit in good condition?Replace P/S control
module.Repair or replace
defective circuit. Step Action Yes No
[A]
123
4567
8
9 11
10 12 13
141516
17 18 1920
1
2
[B]
BRN RED/
BLU LT GRN/
BLK
E11-1
E11-14
E11-12
E13-1 GRN
GRN
WHT
8
3 10
12
13
11
4 1
2
12V
E13-2BLK
12V
12V
9 5
77
E11-11
G04-15
[E]G04-22
5V
PPL
E11-4
BLU/
WHTE04-9
6
14
IG11615
C07-25
[D][C]
[F]E01-44E01-4
[F]E01-27E01-26
I6RW0D630003-01
[A]: P/S control module connector No.1 “E11” (viewed from harness side) 3. Junction block assembly 11. “IGN” fuse
[B]: P/S control module connector No.2 “E13” (viewed from harness side) 4. Main fuse 12. “P/S” fuse
[C]: M/T model 5. ECM 13. “IG1 SIG” fuse
[D]: A/T model 6. BCM 14. Vehicle speed signal
[E]: Junction block without BCM model (Taiwan model) 7. Front left/right wheel speed sensor 15. TCM
[F]: M15A engine with 4A/T equipped with slip control model (Hong Kong model) 8. P/S control module 16. Output shaft speed sensor
1. Main fuse box 9. ABS control module
2. Ignition switch 10. Individual circuit fuse box No.1

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DTC Detecting Condition and Trouble Area
DTC TroubleshootingDTC detecting condition Trouble area
DTC C1121:
Vehicle speed signal is 0 km/h even though engine speed
is more than 4000 rpm for more than 60 seconds
continuously (before elapse of 5 min from engine start)
or
Vehicle speed signal is 0 km/h even though engine speed
is more than 2500 rpm for more than 60 seconds
continuously (after elapse of 5 min for engine start).
(1 driving cycle detection logic but “EPS” warning light
does not light up)
DTC C1123:
Vehicle speed signal is 0 km/h with continuously more
than 3 driving cycles even though engine speed is more
than 4000 rpm for more than 30 seconds continuously
(before elapse of 5 min from engine start)
or
Vehicle speed signal is 0 km/h with continuously more
than 3 driving cycles even though engine speed is more
than 2500 rpm for more than 30 seconds continuously
(after elapse of 5 min for engine start).
(3 driving cycle detection logic)
DTC C1124:
Vehicle speed signal is less than 5 km/h for more than 5
seconds continuously with more than specified
deceleration speed (–20 m/s
2) from over 20 km/h.
(1 driving cycle detection logic but “EPS” warning light
does not light up)• Vehicle speed signal circuit
•BCM
•ECM
• TCM (A/T model)
• ABS control module (M/T model)
• P/S control module
• CAN communication line circuit
Step Action Yes No
1Was “EPS System Check” performed?Go to Step 2. Go to “EPS System
Check”.
2DTC check
1) DTC check for ECM referring to “DTC Check in Section
1A”.
Is there any DTC detected?Go to applicable DTC
diag. flow.Go to Step 3.
3Vehicle spec check
Is vehicle equipped with A/T?Go to Step 4 Go to Step 5
4DTC check
1) Check TCM for DTC referring to “DTC Check in Section
5A”.
Is there any DTC detected?Go to applicable DTC
diag. flow.Go to Step 6.
5DTC check
1) Check ABS control module and BCM for DTC referring
to “DTC Check in Section 4E” and “DTC Check in
Section 10B”.
Is there any DTC detected?Go to applicable DTC
diag. flow.Go to Step 6.

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DTC C1122: Engine Speed SignalS6RW0D6304015
Wiring Diagram6Vehicle speed signal circuit check
1) With ignition switch turned OFF, disconnect connectors
from BCM.
2) Check BCM connector for proper connection.
3) If OK, turn ON ignition switch, measure voltage between
“G04-15” or “G04-22” wire terminal of BCM connector
and body ground.
Is voltage 4 – 5 V?Go to Step 7. Go to Step 8.
7BCM voltage check
1) With ignition switch turned OFF, connect BCM
connector.
2) Check BCM for vehicle speed signal output referring to
“Inspection of P/S Control Module and Its Circuits”.
Is it in good condition?Replace P/S control
module.Replace BCM.
8Vehicle speed signal circuit check
1) Check that vehicle speed signal circuit is as follows.
• Insulation resistance of wire harness is infinity
between “Vehicle speed signal” terminal and other
terminal at P/S control module connector.
• Wiring harness resistance of “Vehicle speed signal”
circuit is less than 1Ω.
• Insulation resistance between “Vehicle speed signal”
circuit and vehicle body ground is infinity.
• Circuit voltage between “Vehicle speed signal” circuit
and ground circuit is 0 – 1 V with ignition switch turned
ON.
Is it in good condition?Replace P/S control
module.Repair or replace
defective circuit. Step Action Yes No
[A]
123
4567
8
9 11
10 12 13
141516
17 18 1920
1
2
[B]
BRN LT GRN/
BLK
E11-1
E11-12
E13-1 GRN
GRN
WHT
6
37
9
10
8
4 12
12V
E13-2BLK12V5
11
[C]E01-44E01-4
I6RW0D630004-01
[A]: P/S control module connector No.1 “E11” (viewed from harness side) 3. Junction block assembly 8. “IGN” fuse
[B]: P/S control module connector No.2 “E13” (viewed from harness side) 4. Main fuse 9. “P/S” fuse
[C]: M15A engine with 4A/T equipped with slip control model (Hong Kong model) 5. ECM 10. “IG1 SIG” fuse
1. Main fuse box 6. P/S control module 11. Engine speed signal circuit
2. Ignition switch 7. Individual circuit fuse box No.1

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Terminal Wire color Circuit Normal voltage Condition
E11-1 LT GRN/BLKIgnition switch signal for P/S
control module10 – 14 V Ignition switch ON
E11-2 — — — —
E11-3 — — — —
E11-4 PPL Vehicle speed signal*0 – 1 V
↑↓
8 – 14 V
(“Reference
waveform No.7”
under “Inspection
of BCM and Its
Circuits in
Section 10B”)• Ignition switch ON
• Front left tire turned quickly with right
tire locked
E11-5 GRY “EPS” warning light0 V Ignition switch ON
0 – 14 V Engine running
E11-6 — — — —
E11-7 — — — —
E11-8 GRN9 V power supply for torque
sensorAbout 9 V• Ignition switch ON
• Voltage between “E11-8” and “E11-9”
terminals
E11-9 BLK Ground for torque sensors — —
E11-10 WHT Torque sensor signal (Sub)About 2.5 – 4.0 V• Steering wheel with left turn
• Out put voltage varies linearly
depending on steering force
About 2.5 V Steering wheel at free
About 1.0 – 2.5 V• Steering wheel with right turn
• Out put voltage varies linearly
depending on steering force
E11-11 BLUSerial communication circuit for
data link connector——
E11-12 BRN Engine speed signal*0 – 1 V
↑↓
8 – 14 V
(“Reference
waveform No.24
and No.25” under
“Inspection of
ECM and Its
Circuits in
Section 1A”)Engine idling
E11-13 — — — —
E11-14 RED/BLU P/S active signal (idle up signal)About 12 V Ignition switch ON
0 – 1 VEngine idling and turned steering wheel
to the right or left until it stops
E11-15 — — — —
E11-16 — — — —
E11-17 — — — —
E11-18 YEL Torque sensor signal (Main)About 1.0 – 2.5 V• Steering wheel with left turn
• Out put voltage varies linearly
depending on steering force
About 2.5 V Steering wheel at free
About 2.5 – 4.0 V• Steering wheel with right turn
• Out put voltage varies linearly
depending on steering force
E11-19 GRY Ground for shield wire — —

Downloaded from www.Manualslib.com manuals search engine 7A-2 Heater and Ventilation:
Schematic and Routing Diagram
Heater and Ventilation Wiring Circuit DiagramS6RW0D7102001
Non–A/C
Manual A/C
Refer to “A/C System Wiring Diagram in Section 7B”.
Auto A/C
Refer to “A/C System Wiring Diagram in Section 7B”.
Component Location
Electronic Control System Components LocationS6RW0D7103001
Refer to “Electronic Control System Components Location in Section 7B” (non-A/C and manual A/C) or “Electronic
Control System Components Location in Section 7B” (auto A/C).
5V
BLK
RED/BLK3
5 72
G154-3
G154-4
G154-7
G154-8
G154-10
G154-13
G155-2
G155-3
G155-7
G155-6
G155-1
G154-9
G154-14
BLK/WHT
YEL
BLU/WHT
RED
RED/BLKRED
GRN
GRN/YEL
RED/YEL
RED/BLU
BLK/ORN
46
8
BLU
YELGRN
WHT
13
1514
[A]21
BLK/RED
12V
BLK/YELBLK/WHTM
BLK
1IG1
IG2
12
BLK/RED
M 10
11
11
BLU/WHT 19
16
17
18 9 20
I6RW0C710003-01
[A]: Illumination control model 6. Blower motor resistor 12. Main fuse box 18. Illumination light
1. Ignition switch 7. Junction block assembly 13. Blower speed selector 19. Rear defogger relay
2. Blower motor 8. BCM 14. Air intake selector 20. Rear defogger
3. HVAC control unit 9. ECM 15. Rear defogger switch 21. Tail light
4. Lighting switch 10. Air intake control actuator 16. “REC” indicator light
5. Blower motor relay 11. To BCM 17. Rear defogger indicator

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Manual A/C Electronic Input Output TableS6RW0D7211002
A/C Operation Description at ECMS6RW0D7211003
ECM controls the A/C compressor relay and condenser cooling fan relay according to signals from HVAC control unit,
A/C refrigerant pressure sensor, ECT sensor and evaporator temperature sensor. The A/C switch ON signal from
HVAC control unit is transmitted to ECM through BCM. For CAN communication system, 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 from HVAC control unit
• A/C refrigerant pressure is within specified range
• Evaporator temperature 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.
ECM
BCM
A/C switch Air intake selector
A/C refrigerant pressure sensor
A/C evaporator temperature sensorCompressor relay
ECT sensor
Condensor cooling fan relay
*
Wheel speed sensor (VSS)
HVAC control unit
Blower motor Blower motor resistor
Air intake control actuator
*Blower speed selector
ABS control module
I6RW0C721001-01
*: CAN communication

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A/C System Wiring DiagramS6RW0D7212002
[A]
7
WHT
GRN5YELBLK
3
G154-3
G154-4
G154-7
G154-8
G154-10
G154-13
G154-5
G154-6
G155-5
G155-2
G155-3
G155-7
G155-6
G155-1
G154-9
G154-14
BLK/WHT
YEL
BLU/WHT
RED
BRN
GRN/WHT
RED/BLK
RED
GRN
GRN/YEL
RED/YEL
RED/BLU
20
21
23 22
BLK/RED
6 2
MBLK/WHTBLK/YEL
M
11
4RED/YEL 1
E01-49
12
E01-16
GRY 13
12V
BLU/WHTE01-3510
E01-48
18
19RED/BLK
BLK/RED
BLK/RED
BRN/WHTE01-60
E01-1
E01-29BLK/WHT
M
BLU/YELBLK/YEL
5V5V 5V
WHT/BLK
9
ORN
14E01-36
C01-12C01-14GRY/REDRED/BLU
E01-41
RED/BLK
RED
WHT
8
BLK
BLK/ORN
BLU IG1
IG2
5V
17
28
29
31
2726 2524
16
16
30
34
33E01-4 E01-19WHTRED
C01-50C01-49WHTRED
32
LT GRN
C01-57
C01-2415
GRY/BLU5V
I6RW0C721002-01
[A]: Illumination control model 9. A/C refrigerant pressure
sensor18. Condenser cooling fan relay 27. Illumination light
1. Ignition switch 10. ECM 19. Condenser cooling fan motor 28. Rear defogger relay
2. Blower motor 11. Air intake control actuator 20. Blower speed selector 29. Rear defogger
3. HVAC control unit 12. Compressor relay 21. A/C switch 30. Main relay
4. Lighting switch 13. Compressor 22. Air intake selector 31. Tail light
5. Blower motor relay 14. Evaporator temperature
sensor23. Rear defogger switch 32. TCM
6. Blower motor resistor 15. ECT sensor 24. “A/C” indicator light 33. To other control module and DLC
7. Junction block assembly 16. To BCM 25. “REC” indicator light 34. ABS control module
8. BCM 17. Main fuse box 26. Rear defogger indicator

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A/C System Symptom DiagnosisS6RW0D7214004
Condition Possible cause Correction / Reference Item
No cool air comes out (A/
C compressor does not
operate)No refrigerantPerform recovery, evacuation and charge
referring to “Operation Procedure for
Refrigerant Charge”.
Fuse blownCheck related fuses, and then check for short
circuit to ground.
A/C switch faultyCheck A/C switch referring to “A/C Switch
Inspection”.
Blower speed selector faultyCheck blower speed selector referring to
“Blower Speed Selector Inspection in Section
7A”.
Evaporator temperature sensor faultyCheck evaporator temperature sensor
referring to “Evaporator Temperature Sensor
Inspection”.
A/C refrigerant pressure sensor faultyCheck A/C refrigerant pressure sensor
referring to “A/C Refrigerant Pressure Sensor
and Its Circuit Inspection”.
Wiring or grounding faultyRepair as necessary.
ECM faultyCheck ECM referring to “A/C System
Inspection at ECM”.
Magnet clutch faultyCheck magnet clutch referring to “Magnet
Clutch Inspection”.
Compressor drive belt loosened or
brokenAdjust or replace drive belt.
Compressor faultyCheck compressor.
Compressor relay faultyCheck compressor relay referring to “A/C
System Relay Inspection”.
BCM faultyCheck 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 blownCheck related fuses, and then check for short
circuit to ground.
Wiring or grounding faultyRepair as necessary.
Condenser cooling fan relay faultyCheck condenser cooling fan motor relay
referring to “A/C System Relay Inspection”.
Condenser cooling fan motor faultyCheck condenser cooling fan motor referring to
“Condenser Cooling Fan Inspection”.
ECM faultyCheck ECM referring to “A/C System
Inspection at ECM”.
No cool air comes out
(blower motor does not
operate)Fuse blownCheck related fuses, and then check for short
circuit to ground.
Blower motor relay faultyCheck blower motor relay referring to “Blower
Motor Relay Inspection in Section 7A”.
Blower motor resistor faultyCheck blower motor resistor referring to
“Blower Motor Resistor Inspection in Section
7A”.
Blower speed selector faultyCheck blower speed selector referring to
“Blower Speed Selector Inspection in Section
7A”.
Wiring or grounding faultyRepair as necessary.
Blower motor faultyCheck blower motor referring to “Blower Motor
Inspection in Section 7A”.

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General Description
Auto A/C System DescriptionS6RW0D7221001
The automatic type air conditioning system (auto A/C) is provided with the function to automatically control the inside
air temperature, fan speed, air flow outlet direction and air intake position by HVAC control module in addition to
functions of the manual type air conditioning system (manual A/C). Once the inside air temperature is set using the
temperature selector, HVAC control module automatically controls the inside air temperature at the constant level at all
times based on the inside air temperature, outside air temperature, amount of sunlight and engine coolant
temperature detected respectively by the inside air temperature sensor, outside air temperature sensor, sunload
sensor and ECT sensor. For the electronic control system components location, refer to “Electronic Control System
Components Location”. For the A/C system components location, refer to “A/C System Major Components Location”.
Auto A/C Electronic Control Input / Output Table
Temperature selector
MODE (air flow) selector
Blower speed selector
Air intake selector
AUTO switch A/C switch
Outside air
temperature
sensor
A/C refrigerant pressure sensor
Compressor relay
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
Sunload sensor
Inside air temperature sensor
Evaporator temperature sensor
Condenser cooling fan relay
Wheel
speed
sensor
*
*
*
Combination meterABS control module
I6RW0C722001-01
*: CAN communication