speed SUZUKI SX4 2006 1.G Service Workshop Manual

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Visual InspectionS6RW0D6304006
Visually check the following parts and systems.)
C1141P/S motor circuit
voltageVoltage between both motor
drive circuit is more than 8.5 V or
less than 0.2 V for 0.5 second
continuously while motor is not
driven.
• P/S motor circuit
• P/S motor
• Torque sensor
• P/S control module1 driving
cycle1 driving
cycle
)
C1142P/S motor circuit range/
performanceMeasured motor drive current is
more than 10 A as compared
with target motor drive current.1 driving
cycle1 driving
cycle
)
C1143P/S motor circuit
current too highMeasured motor drive current is
more than 65 A.1 driving
cycle1 driving
cycle
)
C1145P/S Motor Circuit
Current Too Low Measured motor drive current is
less than 2 A continuously for
more than 3 seconds even
though target motor drive current
is more than 4 A.
or
Measured motor drive current is
less than 0.8 A for total 1 second
even though motor control duty is
more than 90% when target
motor drive current is less than 8
A.1 driving
cycle1 driving
cycle
)
C1153P/S control module
power supply circuitPower supply voltage of P/S
control module is less than 9 V
for 5 seconds continuously while
engine speed is more than 600
rpm• P/S control module
power supply circuit
• Undercharged Battery
• Generator
• P/S control module1 driving
cycle1 driving
cycle
)
C1155P/S control module
internal failureInternal memory (EEPROM) is
data error.• P/S control module1 driving
cycleDoes not
light up
Internal circuit is faulty.
or
Power supply voltage of P/S
control module exceeded 17.5 V• Generator
• P/S control module1 driving
cycle1 driving
cycle DTC No. Detecting itemDetecting condition
(DTC will set when detecting)Trouble area DTC“EPS”
warning
light
Inspection Item Referring section
Battery Level, leakage, color “Battery Description in Section 1J”
Connectors of
electric wire harnessDisconnection friction“Intermittent and Poor Connection Inspection in
Section 00”
Fuses Burning“Cautions in Body Electrical System Servicing in
Section 9A”
Parts Installation, damage
Other parts that can be checked visually

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Scan Tool DataS6RW0D6304007
NOTE
When P/S motor is cold condition (that is, armature coil of P/S motor is not heated), normal value with
asterisk (*) mark in the following table is displayed on scan tool

Scan Tool Data Definitions
Power Supply Voltage
This parameter indicates battery positive voltage.
Sensor Power Supply (Torque Sensor Power Supply,
V)
This parameter indicates the power supply voltage which
the P/S control module supplies to the torque sensor.
Sensor (Main) Torque (Torque Sensor Main Torque,
N⋅m)
The torque sensor is installed to detect the steering force
and the steering direction. It consists of two
potentiometers and the main torque sensor is one of
these.
Sensor (Sub) Torque (Torque Sensor Sub Torque,
N⋅m)
The torque sensor is installed to detect the steering force
and the steering direction. It consists of two
potentiometers and the sub-torque sensor is one of
these. Its output characteristics are compared with those
of the main torque sensor.Control Torque (N⋅m)
This parameter is an internal parameter of the P/S
control module. It is obtained by computing the torque
sensor input signal.
Target Motor Current (Motor Control Current, A)
Based on the input signal, the P/S control module
determines the assist amount and controls the current to
the motor suitable for that assist amount. This parameter
indicates that control value.
Measured MOT Current (Motor Monitor Current, A)
This parameter indicates the actually measured value of
the current flowing to the motor. The motor circuit
condition is diagnosed by comparing this parameter with
“Motor Control” parameter described previously.
Vehicle Speed (km/h, MPH)
Vehicle speed signal is fed from BCM. P/S control
module determines the amount of power assist based on
this vehicle speed signal and the torque sensor signal.
Engine Speed (rpm)
Engine speed signal is fed from the ECM so that it can
be used for trouble diagnosis of the electric power
steering system. Scan tool data Vehicle condition Normal condition
) Power Supply Voltage
Ignition switch ON10 – 14 V
) Sensor Power Supply7.4 – 10 V
) Sensor (Main) TorqueEngine running at idle
speedSteering wheel at fully turned to left –10.5 – 0 N⋅m
Steering wheel at free 0 N⋅m
Steering wheel at fully turned to right 0 – 12.85 N⋅m
) Sensor (Sub) Torque Engine running at idle
speedSteering wheel at fully turned to left 0 – 10.65 N⋅m
Steering wheel at free 0 N⋅m
Steering wheel at fully turned to right –12.85 – 0 N⋅m
) Control TorqueEngine running at idle
speedSteering wheel at fully turned to left –7.22 – 0 N⋅m
Steering wheel at free 0 N⋅m
Steering wheel at fully turned to right 0 – 7.16 N⋅m
) Target Motor CurrentEngine running at idle
speedSteering wheel at free 0 A
Steering wheel at fully turned to left or
right*45 – 60 A
) Measured MOT
Current
Engine running at idle
speedSteering wheel at free 0 A
Steering wheel at fully turned to left or
right*45 – 60 A
) Vehicle Speed Engine running and vehicle at stop 0 km/h
) Engine Speed Engine running at idle speed after warming up 700 ± 50 rpm
) Motor Drive VoltageEngine running at idle
speedSteering wheel at free 0.8 – 1 V
Steering wheel at fully turned to right *5.5 – 8.5 V
) System Power Status
Ignition switch ONON
) IGN switch StatusON
) Torque sensor Status
Engine running at idle speedON
) Fail Safe FET StatusON

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Motor Drive Voltage (V)
This parameter indicates the voltage between motor
terminals.
System Power Status (EPS System Power, ON, OFF)
This parameter indicates input status of EPS system
power supply.
IGN switch Status (ON, OFF)
This parameter indicates the condition of the power
supply through the ignition switch.Torque sensor Status (ON, OFF)
This parameter indicates the output status of the torque
sensor power supply.
Fail Safe FET Status (ON, OFF)
This parameter indicates the status of the motor drive
power supply circuit.
P/S System Symptom DiagnosisS6RW0D6304008
This section describes trouble diagnosis of the P/S system parts whose trouble is not indicated by the on-board
diagnostic system (self-diagnostic function). When no malfunction is indicated by the on-board diagnostic system
(self-diagnosis function) and assuredly those steering basic parts as described in “Steering Symptom Diagnosis in
Section 6A” are all in good condition, check the following power steering system parts which may be a possible cause
for each symptom of the steering.
Condition Possible cause Correction / Reference Item
Steering wheel feels
heavy (Perform “Steering
Force Check:” before
diagnosis.)Steering wheel installed improperly
(twisted)Install steering wheel correctly.
Poor performance of P/S motorCheck P/S motor referring to “P/S Motor and
Its Circuit Inspection”.
Poor performance of torque sensorCheck torque sensor referring to “Torque
Sensor and Its Circuit Inspection”.
Steering gear case assembly
malfunctionReplace steering gear case assembly.
Poor performance of vehicle speed
signal from BCMCheck vehicle speed signal circuit referring to
“DTC C1121 / C1123 / C1124: Vehicle Speed
Signal Circuit Failure”.
Steering wheel feels
heavy momentarily when
turning it to the left or
rightSteering gear case assembly
malfunctionReplace steering gear case assembly.
Poor recovery from turnsPoor performance of torque sensorCheck torque sensor referring to “Torque
Sensor and Its Circuit Inspection”.
Steering gear case assembly
malfunctionReplace steering gear case assembly.
Vehicle pulls to one side
during straight drivingPoor performance of torque sensorCheck torque sensor referring to “Torque
Sensor and Its Circuit Inspection”.
Steering gear case assembly
malfunctionReplace steering gear case assembly.
Abnormal noiseP/S motor (built in steering gear case
assembly) malfunctionReplace steering gear case assembly.
No idle upP/S control module faultyCheck P/S control module referring to
“Inspection of P/S Control Module and Its
Circuits”.

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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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DTC Detecting Condition and Trouble Area
DTC TroubleshootingDTC detecting condition Trouble area
Engine speed signal is less than 220 rpm for more than
0.8 seconds.
or
Engine speed signal is less than 220 rpm for more than 20
seconds continuously even though vehicle speed signal is
more than 50 km/h.
(1 driving cycle detection logic)• Engine speed signal circuit
•ECM
• P/S control module
Step Action Yes No
1Was “EPS System Check” performed?Go to Step 2. Go to “EPS System
Check”.
2DTC check
1) Check ECM for DTC referring to “DTC Check in Section
1A”.
Is there any DTC(s) detected?Go to applicable DTC
diag. flow.Go to Step 3.
3Engine speed signal circuit check
1) With ignition switch turned OFF, disconnect P/S control
module connector.
2) Check P/S control module connector for proper
connection.
3) If OK, turn ON ignition switch, measure voltage between
“E11-12” wire terminal of P/S control module connector
and vehicle body ground.
Is voltage 10 – 14 V?Go to Step 4. Go to Step 5.
4ECM voltage check
1) With ignition switch turned OFF, connect P/S control
module and ECM connectors.
2) Check engine speed signal output referring to
“Inspection of ECM and Its Circuits in Section 1A”.
Is it in good condition?Substitute a known-
good P/S control
module and recheck.Substitute a known
good ECM and recheck.
5Engine speed signal circuit check
1) Disconnect ECM connector.
2) Check that engine speed signal circuit is as follows.
• Insulation resistance of wire harness is infinity
between “Engine speed signal circuit” terminal and
other terminal at P/S control module connector.
• Wiring harness resistance of “Engine speed signal
circuit” is less than 1Ω.
• Insulation resistance between “Engine speed signal
circuit” and vehicle body ground is infinity
• Circuit voltage between “Engine speed signal circuit”
and ground circuit is 0 – 1 V with ignition switch turned
ON.
Is it in good condition?Substitute a known
good ECM and recheck.Repair or replace
defective circuit.

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DTC Troubleshooting
DTC C1153: P/S Control Module Power Supply CircuitS6RW0D6304017
Wiring Diagram
DTC Detecting Condition and Trouble AreaStep Action Yes No
1Was “EPS System Check” performed?Go to Step 2. Go to “EPS System
Check”.
2DTC check
Is DTC C1153 and/or C1155 indicated, together?Go to applicable DTC
diag. flow.Go to Step 3.
3Power supply and ground circuit check
1) Check P/S control module power supply and ground
circuit referring to “P/S Control Module Power Supply
and Ground Circuit Check”.
Is it in good condition?Go to Step 4. Repair or replace
defective circuit.
4Motor circuit check
1) With ignition switch turned OFF, disconnect P/S control
module connector No.3 and P/S motor connector.
2) Check P/S control module connector and P/S motor
connector for proper connection.
3) If OK, check for open, short and/or high resistance in
motor circuit between P/S control module and P/S motor.
Refer to “Electrical Circuit Inspection Procedure in
Section 00”.
Are they in good condition?Go to Step 5. Repair motor circuit.
5P/S motor check
1) Check P/S motor referring to “P/S Motor and Its Circuit
Inspection”.
Is P/S motor in good condition?Substitute a known-
good P/S control
module and recheck.Replace the steering
gear case assembly and
recheck.
[A]
123
4567
8
9 11
10 12 13
141516
17 18 1920
1
2
[B]
LT GRN/
BLKE11-1E13-1 GRNGRN
WHT
5
3 6
8
9
7
4 12
12V
E13-2BLK
I6RW0C630009-01
[A]: P/S control module connector No.1 “E11” (viewed from harness side) 3. Junction block assembly 7. “IGN” fuse
[B]: P/S control module connector No.2 “E13” (viewed from harness side) 4. Main fuse 8. “P/S” fuse
1. Main fuse box 5. P/S control module 9. “IG1 SIG” fuse
2. Ignition switch 6. Individual circuit fuse box No.1
DTC detecting condition Trouble area
Power supply voltage of P/S control module is less than 9
V for 5 seconds continuously while engine speed is more
than 600 rpm.
(1 driving cycle detection logic)• P/S control module power supply circuit
• Battery
• Generator
• P/S control module

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DTC Troubleshooting
DTC C1155: P/S Control Module Internal FailureS6RW0D6304018
Wiring Diagram
Refer to “DTC C1153: P/S Control Module Power Supply Circuit”.
DTC Detecting Condition and Trouble Area
DTC TroubleshootingStep Action Yes No
1Was “EPS System Check” performed?Go to Step 2. Go to “EPS System
Check”.
2Battery voltage check
1) Check circuit fuse for P/S control module.
2) If OK, measure voltage between positive (+) battery
terminal and vehicle body ground with engine running.
Is voltage 10 V or more?Go to Step 3. Check charging system
referring to “Generator
Test (Undercharged
Battery Check) in
Section 1J”.
3P/S control module power supply circuit check
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 defective circuit.
DTC detecting condition Trouble area
Internal memory (EEPROM) is data error.
(In this case, “EPS” warning light does not light up)
or
Internal circuit is faulty.
or
Power supply voltage of P/S control module exceeded
17.5 V
(1 driving cycle detection logic)• Generator
• P/S control module
Step Action Yes No
1Was “EPS System Check” performed?Go to Step 2. Go to “EPS System
Check”.
2P/S control module power supply and ground circuit
check
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?Go to Step 3. Repair or replace
defective circuit.
3Battery voltage check
1) Check voltage between positive (+) battery terminal and
vehicle body ground with engine speed at 3000 rpm.
Is voltage 15.5 V or less?Replace P/S control
module.Check charging system
referring to “Generator
Test (Overcharged
Battery Check) in
Section 1J”.

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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 — —