Signal SUZUKI SWIFT 2007 2.G Service Workshop Manual

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DTC TroubleshootingStep Action Yes No 1 Was “EPS System Check” performed? Go to Step 2. Go to “EPS System
Check”.
2 DTC check
Is DTC C1113, C1114 and/or DTC C1119 indicated together? Go to applicable diag.
flow.
Go to Step 3.
3 Torque sensor internal failure signal voltage check
1) Check for P/S control module connector (“E52”) for
proper connection.
2) Check for voltage between “E52-16” (“YEL” wire) terminal and body ground with ignition switch ON.
Is voltage 0 – 1 V? Substitute a known-
good P/S control
module and recheck.
Go to Step 4.
4 Torque sensor internal failure signal circuit check
1) With ignition switch turned OFF, disconnect torque
sensor connector.
2) Check for voltage between “E53-1” (“YEL” wire) terminal and body ground with ignition switch ON.
Is it about 5 V? Go to Step 5. Go to Step 6.
5 Torque sensor internal failure signal circuit check
1) Disconnect P/S control module connector.
2) Check that torque sensor failure signal circuit is as
follows.
• Insulation resistance of wire harness is infinity between “Torque sensor internal failure signal circuit”
terminal and other terminal at torque sensor
connector.
Is circuit in good condition? Go to Step 7. Repair or replace
defective circuit.
6 Torque sensor internal failure signal circuit check
1) Disconnect P/S control module connector.
2) Check that torque sensor failure signal circuit is as
follows.
• Insulation resistance of wire harness is infinity between “Torque sensor internal failure signal circuit”
terminal and other terminal at torque sensor
connector.
• Wiring harness resistance of “Torque sensor internal failure signal circuit” is less than 1 Ω.
Is circuit in good condition? Substitute a known-
good P/S control
module and recheck.
Repair or replace
defective circuit.
7 Torque sensor signal circuit check
1) Check for torque sensor signal circuit referring to Step 3)
– 8) of “DTC C1113: Steering Torque Sensor (Main and
Sub) Circuit Correlation”.
Is torque sensor and its circuit in good condition? Replace steering gear
case.
Repair or replace
defective parts.

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DTC C1121 / C1123 / C1124: VSS Circuit FailureS7RS0B6304017
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 Diagram
DTC Detecting Condition and Trouble Area
M
BRNRED/
BLU
BLK
RED
E52-14
E52-12
E23-4
E23-26
E23-25 E51-1
E51-2
[A ]
12
3
4 5 67
89
11
10
12 13
141516
17 18 19 20
5V
PPL
E52-4
8
5
12V
E49-2BLK
12V
12V
6REDRED/ BLKWHT
7WHTWHT/BLKWHTBLK BLK
111
2
[B ]
9
LT GRN
/BLKE52-1 E49-1
GRNGRNWHTBLK
WHY
10
3
4
4
4
4
1 2
12
I7RS0B630009-01
[A]: Connector “E52” (viewed from harness side)
4. Fuse9. ABS/ESP® control module
[B]: Connector “E49” (viewed from harness si de)5. ECM 10. Individual circuit fuse box No.1
1. Main fuse box 6. Left-front wheel speed sensor11. Vehicle speed signal circuit
2. Ignition switch 7. Right-front wheel speed sensor 12. Engine speed signal circuit
3. Junction block assembly 8. P/S control module
DTC 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 MIL 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 MIL does not light up) • Vehicle speed signal circuit
• Wheel speed sensor
•ECM
• P/S control module
• ABS/ESP®
control module
• CAN communication circuit

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DTC TroubleshootingStep Action Yes No 1 Was “EPS System Check” performed? Go to Step 2. Go to “EPS System
Check”.
2 DTC check
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.
3 DTC check
1) Check ABS control module for DTC referring to “DTC
Check in Section 4E”.
Is there any DTC detected? Go to applicable DTC
diag. flow.
Go to Step 4.
4 Vehicle speed signal circuit check
1) With ignition switch turned OFF, disconnect connectors
from ECM.
2) Check ECM connector for proper connection.
3) If OK, turn ON ignition switch, measure voltage between “E23-25” wire terminal of ECM connector and body
ground.
Is voltage 4 – 5 V? Go to Step 6.
Go to Step 5.
5 Vehicle speed signal circuit check
1) With ignition switch turned OFF, disconnect P/S control
module connector “E52”.
2) Check for proper terminal connection to P/S control module connector and ECM connector.
3) If connections are OK, chec k that “Vehicle speed signal
circuit” is as following.
• Insulation resistance of “Vehicle speed signal circuit” wire harness is infinity between its terminal and other
terminals at ECM and P/S control module connector.
• Wiring resistance of “Vehicle speed signal circuit” is less than 1 Ω.
• Insulation resistance of “Vehicle speed signal circuit” between its 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 circuit in good condition? Replace P/S control
module.
Repair or replace
defective circuit.
6 ECM voltage check
1) Connect P/S control mo dule and ECM connectors.
2) Check ECM for vehicle speed signal output referring to “Inspection of ECM and Its Circuits in Section 1A”.
Is check result in good condition? Replace P/S control
module.
Replace ECM.

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DTC C1122: Engine Speed SignalS7RS0B6304018
NOTE
DTC C1122 (engine speed signal failure) is indicated when ignition switch is at ON position and engine
is not running, but means there is nothing abnormal if indication changes to a normal one when
engine is started.

Wiring Diagram
Refer to “DTC C1121 / C1123 / C1124: VSS Circuit Failure”.
DTC Detecting Condition and Trouble Area DTC 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
• Vehicle speed signal circuit

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DTC TroubleshootingStep Action Yes No 1 Was “EPS System Check” performed? Go to Step 2. Go to “EPS System
Check”.
2 DTC check
1) Clear DTC(s) referring to “DTC Clearance”.
2) Run engine at idle speed.
3) Check if any DTC is detecte d referring to “DTC Check”.
Is DTC C1122 still detected? Go to Step 3. Check intermittent
trouble referring to
“Intermittent and Poor
Connection Inspection
in Section 00”.
3 DTC check
1) Check ECM for DTC referring to “DTC Check in Section
1A”.
Is there any DTC related to engine speed? Go to applicable DTC
diag. flow.
Go to Step 4.
4 Engine 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 “E52-12” wire terminal of P/S control module connector
and vehicle body ground.
Is voltage 10 – 14 V? Go to Step 6.
Go to Step 5.
5 1) With ignition switch turned OFF, disconnect ECM connector.
2) Check for proper connection to the P/S control module and ECM at each “Engine speed signal circuit” terminal.
3) If connections are OK, chec k that “Engine speed signal
circuit” is as following.
• Insulation resistance of “Engine speed signal circuit” wire is infinity between its terminal and other terminals
at ECM and P/S control module connector.
• Wiring resistance of “Engine speed signal circuit” terminal are less than 1 Ω.
• Insulation resistance of “Engine speed signal circuit” between its terminal 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 circuit in good condition? Go to Step 6.
Repair engine speed
signal circuit.
6 ECM voltage check
1) Connect P/S control mo dule and ECM connectors.
2) Check ECM for engine speed signal and vehicle speed signal output voltage to P/S control module referring to
“Inspection of ECM and Its Circuits in Section 1A”.
Is check result in good condition? Substitute a known-
good P/S control
module and recheck.
Substitute a known-
good ECM and recheck.

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P/S Control Module Power Supply and Ground Circuit CheckS7RS0B6304022
Wiring Diagram
1
[A ]
123
4 5 67
89
11
10
12 13
141516
17 18 19 20
[B ]
7
1
2
MBLK
REDE51-1
E51-2
12V
LT GRN
/BLKE52-1 E49-1
GRNGRNWHTBLK
WHY
3
3
5
6
1 2
E49-2BLK
I7RS0B630012-01
[A]: Connector “E52” (viewed from harness side)
2. Ignition switch5. “EPS” fuse
[B]: Connector “E49” (viewed from harness side) 3. Individual circuit fuse box No.1 6. “IG1 SIG” fuse
1. Main fuse box 4. Junction block assembly7. P/S control module
StepAction YesNo
1 Circuit fuse check
1) Disconnect P/S control modu le connector with ignition
switch turned OFF.
2) Check for proper connection to P/S control module connector at “E49-1”, “E49-2” and “E52-1” terminals.
3) If OK, check “P/S” fuse and “IG1 SIG” fuse for blowing.
Are “P/S” fuse and “IG1 SIG” fuse in good condition? Go to Step 2.
Replace fuse(s) and
check for short in
circuits connected to
fuse(s).
2 Power supply circuit check
1) Measure voltage between “E49-1” terminal of P/S
control module connector and body ground.
Is voltage 10 - 14 V? Go to Step 3.
“GRN” or “BLK” wire is
open circuit.
3 Ignition signal check
1) Turn ignition switch to ON position.
2) Measure voltage between “E52-1” terminal of P/S
control module connector and body ground.
Is voltage 10 - 14 V? Go to Step 4.
“LT GRN/BLK” or “GRN”
wire is open circuit.
4 P/S control module ground circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from P/S control module.
3) Measure resistance between “E49-2” terminals of P/S
control module connector and body ground.
Is resistance 1
Ω or less? Go to Step 5. “BLK” wire is open or
high resistance circuit.

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Voltage Check1) Remove console box.
2) Check for voltage at each terminal with co nnectors connected to the P/S control module.
NOTE
As each terminal voltage is affected by the battery voltage, confirm if the battery voltage is 11 V or
more when ignition switch is ON.
*: The voltage of this circuit may not be checked by voltmeter. If so, use oscilloscope.

Terminal Wire colorCircuit Normal voltage Remarks
E49-1 GRN Main power supply for
internal memory and P/S
motor 10 – 14 V
—
E49-2 BLK Ground for P/S control
module Below 0.3 V
—
E51-1 BLK Motor output 1 *0 – 1 V
↑↓
10 – 14 V
(“Reference
waveform No.1: ”, “Reference
waveform No.2:
”and “Reference
waveform No.3: ”) • Engine idling and steering wheel at
straight position
• Voltage between “E51-1” and vehicle body ground
E51-2 RED Motor output 2 *0 – 1 V
↑↓
10 – 14 V
(“Reference
waveform No.1: ”, “Reference
waveform No.2: ” and “Reference
waveform No.3: ”) • Engine idling and steering wheel at
straight position
• Voltage between “E51-2” and vehicle body ground
E52-1 LT GRN/BLK Ignition switch signal for P/S
control module 10 – 14 V Ignition switch ON
E52-2 — —— —
E52-3 — —— —
E52-4 PPL Vehicle speed signal *0 – 1 V
↑↓
8 – 14 V
(“Reference
waveform No.9”
under “Inspection of
ECM and Its Circuits in Section 1A”.) • Ignition switch ON
•Front left tire tu
rned quickly with right
tire locked
E52-5 GRY “EPS” warning light 0 V “EPS” warning light OFF
E52-6 BLU Torque sensor signal (Sub) About 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 – 6 V • Steering wheel with right turn
• Out put voltage varies linearly
depending on steering force
E52-7 — —— —
E52-8 GRN Main power supply for torque
sensor About 12 V• Ignition switch ON
• Check voltage between “E52-8” and
“E52-9” terminals
E52-9 BRN Ground for torque sensors Below 0.3 V —
E52-10 — —— —

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E52-11 PPL/WHT Data link connector——
E52-12 BRN Engine speed signal *0 – 1 V
↑↓
8 – 14 V
(“Reference
waveform No.30” and “Reference
waveform No.31”
under “Inspection of
ECM and Its Circuits in Section 1A”.) Engine idling
E52-13 — —— —
E52-14 RED/BLU P/S operation signal (idle up
signal) About 12 V Ignition switch ON
0 – 1 V Engine idling and turned steering
wheel to the right or left until it stops
E52-15 — —— —
E52-16 YEL Torque sensor internal failure
signal About 5 V At the moment of Ignition switch ON
0 V Ignition switch ON
E52-17 — —— —
E52-18 WHT Torque sensor signal (Main) About 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 – 6 V • Steering wheel with right turn
• Out put voltage varies linearly
depending on steering force
E52-19 GRY Ground for shield wire Below 0.3 V—
E52-20 RED 5 V reference power supply
for torque sensor About 5 V• Ignition switch ON
• Check voltage between “E52-20”
and “E52-9” terminals
Terminal Wire color
Circuit Normal voltage Remarks

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Reference waveform No.1
Motor output signal 1(1), Motor output signal 2(2), with
engine idlingReference waveform No.2
Motor output signal 1(1), Motor output signal 2(2), with
engine idling
Measurement
terminal CH1: “E51-1” to vehicle body ground
CH2: “E51-2” to vehicle body ground
Oscilloscope
setting CH1: 5 V/DIV, CH2: 5 V/DIV
TIME: 20
µs/DIV
Measurement
condition • Engine is idling and steering wheel
at straight position
I6RS0B630017-01
Measurement
terminal CH1: “E51-1” to vehicle body ground
CH2: “E51-2” to vehicle body ground
Oscilloscope
setting CH1: 5 V/DIV, CH2: 5 V/DIV
TIME: 20 µ
s/DIV
Measurement
condition • Engine is idling and steering wheel
is turned to left or right at turning
speed of 90 ° /sec
[A]: Steering wheel is turned left at turning speed of 90 ° /sec
[B]: Steering wheel is turned right at turning speed of 90 ° /sec
[C]: 12 V ON
[D]: GND ON [E]: 1 duty cycle
I6RS0B630018-01

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Reference waveform No.3
Motor output signal 1(1), Motor output signal 2(2), with
engine idling
Steering Wheel Play CheckS7RS0B6304024
• Check steering wheel for looseness or rattle by moving it in its shaft direction and lateral direction.
If found defective, repair or replace.
• Check steering wheel for play, holding vehicle in straight forward condition on the ground with engine
stopped.
If steering wheel play is not within specification,
inspect as follows and replace if found defective.
• Tie-rod end ball stud for wear (Ball stud should move when more than 0.2 N ⋅m (2 kg-cm, 0.44 lb-ft) torque is
applied.)
• Lower ball joint for wear
• Steering shaft joint for wear • Steering pinion or rack gear for wear or breakage
• Each part for looseness
Steering wheel play
“a”
: 0 – 30 mm (0 – 1.18 in.)
Steering Force CheckS7RS0B6304025
1) Place vehicle on level road and set steering wheel at
straight-ahead position.
2) Check if tire inflation pressure is as specified referring to the tire placard.
3) Remove driver air bag (inflator) module referring to “Driver Air Bag (Inflator) Module Removal and
Installation in Section 8B”.
4) Start engine.
5) With engine idling, measure steering force by turning torque wrench.
Steering force
: Less than 6.4 N ⋅m (0.64 kgf-m, 4.6 lb-ft)
6) Install driver air bag (inflator) module referring to “Driver Air Bag (Inflator) Module Removal and
Installation in Section 8B”.
Measurement
terminal
CH1: “E51-1” to vehicle body ground
CH2: “E51-2” to vehicle body ground
Oscilloscope
setting CH1: 5 V/DIV, CH2: 5 V/DIV
TIME: 20
µs/DIV
Measurement
condition • Engine is idling and steering wheel
is kept fully turned to left or right
until it stops
[A]: Steering wheel is kept fully turned left until it stops
[B]: Steering wheel is kept fully turned right until it stops
[C]: 12 V ON
[D]: GND ON
I6RS0B630019-01
I3RM0A630021-01
I3RM0A630022-01