check engine SUZUKI SWIFT 2005 2.G Service Workshop Manual

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EPS Diagnosis General DescriptionS7RS0B6301002
The P/S system in this vehicle is controlled by the P/S control module. T he P/S control module has an on-board
diagnostic system which detects a malfunction in this system. When diagnosing troubles, be sure to have full
understanding of the outline of “On-Board Diagnostic Sy stem Description” and each item in “Precautions in
Diagnosing Troubles”, and then execute diagnosis according to “EPS System Check”.
On-Board Diagnostic System DescriptionS7RS0B6301003
The P/S control module performs the on -board diagnosis (self-diagnosis) on the system and operates the “EPS”
warning light (1) as follows.
• The “EPS” warning light lights when the ignition switch is turned to ON position (but the engine at stop) regardless
of the condition of the P/S co ntrol system. This is only to check if the “EPS” warning light is operated properly.
• If the areas monitored by the P/S control module is free from any trouble after the engine start (while engine is
running), the “EPS” warning light turns OFF.
• When the P/S control module detects a trouble which has occurred in th e monitored areas the “EPS” warning light
comes ON while the engine is running to warn the driver of such occurrence of the trouble and at the same time it
stores the exact trouble area in memory inside of the P/S control module.
Driving Cycle
A “Driving Cycle” consists of en gine startup and engine shutoff.
3 Driving Cycles Detection Logic
The malfunction detected in the first and second driving cycl e is stored in P/S control module memory (in the form of
pending DTC) but the “EPS” wa rning light does not light at these time. It lights up at t he third detection of same
malfunction also in the next driving cycle.
1
I6RS0C630002-01

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Terminal Arrangement of P/S Control Module Coupler (Viewed from Harness Side)
Diagnostic Information and Procedures
EPS System CheckS7RS0B6304001
WARNING!
Carry out test drive in light traffic area to prevent an accident.

Refer to the following items for the details of each step.Terminal Circuit Terminal Circuit
E49-1 Main power supply for internal memory
and EPS motor E52-9 Ground for torque sensors
E49-2 Ground for P/S control module E52-10 —
E51-1 Motor output 1 E52-11 Serial communication for data link
connector
E51-2 Motor output 2 E52-12 Engine speed signal
E52-1 Ignition switch signal for P/S control
module E52-13 —
E52-2 — E52-14 P/S operation signal (idle up signal)
E52-3 — E52-15 —
E52-4 Vehicle speed signal E52-16 Torque sensor internal failure signal
E52-5 “EPS” warning light E52-17 —
E52-6 Torque sensor signal (Sub) E52-18 Torque sensor signal (Main)
E52-7 — E52-19 Ground for shield wire
E52-8 Main power supply for torque sensor E52-20 5 V reference power supply for torque
sensor
Step
Action YesNo
1 ) Customer complaint analysis
1) Perform customer complaint analysis referring to “Customer Complaint Analysis”.
Was customer complaint analysis performed? Go to Step 2.
Perform customer
complaint analysis.
2 ) DTC check, record and clearance
1) Check for DTC (including pending DTC) referring to “DTC Check”, Record and Clearance.
Is there any DTC(s)? Print DTC or write them
down and clear them by
referring to “DTC
Clearance” and go to
St ep 3 .Go to Step 4.
3 ) Visual inspection
1) Perform visual inspection referring to “Visual Inspection”.
Is there any faulty condition? Repair or replace
malfunction part, and go
to Step 11.
Go to Step 5.
4 ) Visual inspection
1) Perform visual inspection referring to “Visual Inspection”.
Is there any faulty condition? Repair or replace
malfunction part, and go
to Step 11.
Go to Step 8.
5 ) Trouble symptom confirmation
1) Confirm trouble symptom referring to “Trouble Symptom Confirmation”.
Is trouble symptom identified? Go to Step 6.
Go to Step 7.
6 ) Rechecking and record of DTC
1) Recheck for DTC referring to “DTC Check”.
Is there any DTC(s)? Go to Step 9.
Go to Step 8.

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NOTE
• As execution of “DTC Clearance” will clear all DTCs, be sure to record all DTCs before service.
• DTC C1122 is indicated when ignition switch is at ON position and engine is not running, it means
that nothing is abnormal.
• Current DTC and history DTC ca n be identified by condition of the “EPS” warning light.
“EPS” warning light operates as follows.

7 ) Rechecking and record of DTC
1) Recheck for DTC referring to “DTC Check”.
Is there any DTC(s)? Go to Step 9. Go to Step 10.
8 ) Steering symptom diagnosis and P/S system
symptom diagnosis
1) Check and repair according to “Steering Symptom Diagnosis in Section 6A” and “P/S System Symptom
Diagnosis”.
Are check and repair complete? Go to Step 11. Check and repair
malfunction part(s), and
go to Step 11.
9 ) Troubleshooting for DTC
1) Check and repair according to applicable DTC diag. flow.
Are check and repair complete? Go to Step 11. Check and repair
malfunction part(s), and
go to Step 11.
10 ) Intermittent problems check
1) Check for intermittent problems referring to “Intermittent Problems Check”.
Is there any faulty condition? Repair or replace
malfunction part(s), and
go to Step 11.
Go to Step 11.
11 ) Final confirmation test
1) Clear DTC if any.
2) Perform final confirmation test referring to “Final Confirmation Test”.
Is there any problem symptom, DTC or abnormal condition? Go to Step 6. End.
Step Action Yes No
Current DTC is set.
(Abnormality exists at
present.)
Only history DTC is set.
(Faulty condition occurred once
in the past, but normal condition
is detected at present.)
Current and history DTC
exist.
“EPS” warning light
after engine started Remains ON. Turns OFF. Remains ON.

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Step 1: Customer Complaint Analysis
Record details of the problem (failure, co mplaint) and how it occurred as described by the customer. For this purpose,
use of such an inspection form will fac ilitate collecting information to the point required for proper analysis and
diagnosis. Check if the problem described in “Customer ques tionnaire” occurs actually in the vehicle if necessary.
(This step should be performed with the customer if possible.) Customer problem inspection form (Example)
NOTE
This form is a standard sample. It should be modified according to conditions characteristic of each
market.

I7RW01632004-02

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Step 2: DTC Check, Record and Clearance
First, check DTC, referring to “DTC Check”. If DTC is
indicated, print it or write them down and then clear them
by referring to “DTC Clearance”. DTC indicates
malfunction that occurred in the system but does not
indicate whether it exists now or it occurred in the past
and the normal condition has been restored now. To
check which case applies, check the symptom in
question according to Step 5 and recheck DTC
according to Step 6 and 7.
Attempt to diagnose a trouble based on DTC in this step
only or failure to clear the DTC in this step will lead to
incorrect diagnosis, trouble diagnosis of a normal circuit
or difficulty in troubleshooting.
Step 3 and 4: Visual Inspection
As a preliminary step, be sure to perform visual check of
the items that support proper function of the P/S system
referring to “Visual Inspection”.
Step 5: Trouble Symptom Confirmation
Based on information obtained in “Step 1: Customer
Complaint Analysis: ” and “S tep 2: DTC Check, Record
and Clearance: ”, confirm trouble symptoms. Also,
reconfirm trouble symptom by performing test drive and
turning steering wheel fully to right and left at stopped
vehicle.
Step 6 and 7: Rechecking and Record of DTC
Refer to “DTC Check” for checking procedure.
Step 8: Steering Symptom Diagnosis and P/S
System Symptom Diagnosis
Perform basic steering system check according to
“Steering Symptom Diagnosis in Section 6A” first. When
the end of the flow has been reached, check the parts of
the system suspected as a possible cause referring to
“P/S System Symptom Diagnosis” and based on
symptoms appearing on the vehicle (symptoms obtained
through steps of customer complaint analysis, trouble
symptom confirmation and/or basic P/S system check)
and repair or replace faulty parts, if any.
Step 9: Troubleshooting for DTC (See each DTC
Diag. Flow)
Based on the DTC indicated in Step 6 or 7 and referring
to the applicable DTC diag. flow, locate the cause of the
trouble, namely in a sensor, switch, wire harness,
connector, actuator, P/S control module or other part and
repair or replace faulty parts.
Step 10: Intermittent Problems Check
Check parts where an intermittent trouble is easy to
occur (e.g., wire harness, connector, etc.), referring to
“Intermittent and Poor Connection Inspection in Section
00” and related circuit of DTC recorded in Step 2. Step 11: Final Confirmation Test
Confirm that the problem symptom has gone and the P/
S system is free from any abnormal conditions. If what
has been repaired is related to the DTC, clear the DTC
once, perform DTC confirmation procedure and confirm
that no DTC is indicated.
“EPS” Warning Light CheckS7RS0B6304002
1) Turn ignition switch to ON position (without engine
running) and chec k if the “EPS” warning light (1)
lights up. If the light dose not light up, go to ““EPS”
Warning Light Does Not Come ON with Ignition
Switch Turned ON before Engine Starts” of the
diagnostic flows.
2) Start engine and check if the “EPS” warning light turns OFF. If light remains ON and no DTC is stored
in P/S control module, go to ““EPS” Warning Light
Remains ON Steady after Engine Starts” for
troubleshooting.
DTC CheckS7RS0B6304003
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 tool
1
I6RS0C630002-01
(A)
1
I4RS0B450003-01

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3) Start engine.
4) Read DTC according to the instructions displayed on
SUZUKI scan tool. For further details, refer to
operator’s manual for SUZUKI scan tool.
NOTE
• If communication between SUZUKI scan tool and the vehicle can not be
established, perform “Serial Data Link
Circuit Check”.
• DTC C1122 (engine speed signal failure) is indicated when ignition switch is at ON
position and engine is not running, but it
means there is nothing abnormal if
indication changes to a normal one when
engine is started.

5) After completing the check, turn ignition switch to
OFF position and disconnect SUZUKI scan tool from
DLC.
DTC ClearanceS7RS0B6304004
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 tool
3) Turn ignition switch to ON position.
4) Erase DTC according to the instructions displayed on SUZUKI scan tool. For further details, refer to
operator’s manual for SUZUKI scan tool.
5) After completing the clearance, turn ignition switch to OFF position and disconnect SUZUKI scan tool from
DLC.
DTC TableS7RS0B6304005
CAUTION!
Be sure to perform the “EPS Syst em Check” before starting troubleshooting corresponding to each
DTC.

(A)
1
I4RS0B450003-01
DTC No. Detecting item Detecting condition
(DTC will set when detecting) Trouble area MIL
No
CODES Normal — — —
) C1113 Steering torque sensor (Main
and Sub) circuit correlation Voltage difference between torque
sensor main signal and sub signal
is more than 0.6 V for 1 second
continuously. • Torque sensor signal circuit
• Torque sensor
• P/S control module
1 driving
cycle
) C1114 Steering torque sensor
reference power supply
circuit Circuit voltage of torque sensor 5
V reference power supply voltage
is more than 5.7 V or less than 4.3
V for 1 second continuously. • Torque sensor circuit
• Torque sensor
• P/S control module
1 driving
cycle
) C1117 Steering torque sensor
failure signal circuit low Torque sensor internal failure
signal circuit voltage is less than
1.7 V when ignition switch turned
ON.
• Torque sensor signal circuit
• Torque sensor
• P/S control module1 driving
cycle
) C1118 Steering torque sensor
failure signal circuit high Torque sensor internal failure
signal circuit voltage is more than
3.7 V for 1 second continuously. 1 driving
cycle
) C1119 Steering torque sensor
power supply circuit Circuit voltage of torque sensor
main power supply
is less than
7.5 V for 1 second continuously. • Torque sensor circuit
• Torque sensor
• P/S control module
1 driving
cycle

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Scan Tool Data Definitions
Battery Voltage
This parameter indicates battery positive voltage.
TQS 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.
TQS Main Torque (Torque Sensor Main Torque, N ⋅m)
The torque sensor is installed to detect the steering force
and the steering directio n. It consists of two
potentiometers and the main torque sensor is one of
these.
TQS Sub Torque (Torque Sensor Sub Torque, N ⋅m)
The torque sensor is installed to detect the steering force
and the steering directio n. 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.
Assist 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. Motor Control (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 a ssist amount. This parameter
indicates that control value.
Motor Monitor (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 co mparing 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 diagnos is of the electric power
steering system.
Motor Volt (V)
This parameter indicates the voltage between motor
terminals.
Ignition switch (ON, OFF)
This parameter indicates the condition of the power
supply through the ignition switch.
Visual InspectionS7RS0B6304007
Visually check the following pats and system.
P/S System Symptom DiagnosisS7RS0B6304008
This section describes trouble diagnosis of the P/S system parts whose trouble is not indicated by the on-board
diagnostic system (self-diagnostic functi on). When no malfunction is indicated by the on-board diagnostic system
(self-diagnosis function) and those stee ring basic parts as described in “Steering Symptom Diagnosis in Section 6A”
are all in good condition, check the following power steer ing system parts which may be a possible cause for each
symptom of the steering. Inspection Item Referring section
Battery Level, leakage, color “Batte ry Description in Section 1J”
Connectors of electric wire
harness Disconnection friction “Intermittent and Poor
Connection Inspection in Section 00”
Fuses Burning “Cautions in Body Electric al System Servicing in Section 9A”
Parts Installation, damage
Other parts that can be checked visually
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 torque sensor Check torque sensor referring to “Torque
Sensor and Its Circuit Inspection”.
Poor performance of P/S motor Check motor referring to “P/S Motor and Its
Circuit Inspection”.
Steering gear case assembly faulty Replace.
Poor performance of vehicle speed
signal from ECM Check vehicle speed signal circuit referring to
“DTC C1121 / C1123 / C1124: VSS Circuit
Failure”.

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Serial Data Link Circuit CheckS7RS0B6304009
CAUTION!
Be sure to perform “EPS System Check” before starting “Troubleshooting”.

Wiring DiagramVehicle pulls to one side
during straight driving
Poor performance of torque sensor
Check torque sensor referring to “Torque
Sensor and Its Circuit Inspection”.
Steering gear case assembly faulty Replace.
Poor recovery after turns Poor performance of torque sensor Check torque sensor referring to “Torque
Sensor and Its Circuit Inspection”.
Steering column faulty Replace.
Abnormal noise P/S motor (built in steering gear case
assembly) malfunction Replace steering gear case assembly.
No idle up P/S control module faulty Check P/S control module referring to
“Inspection of P/S Control Module and Its
Circuits”.
Condition Possible cause Correction / Reference Item
MBLK
RED
E52-11 E51-1
E51-2PPL/WHT
[A ]
12
3
4 5 67
89
11
10
12 13
141516
17 18 19 2010 9 8 7654 3 21
16 15 14 13 12 11
26 25 24 2322 21 20 19 18 17
32 31 30 29 28 27
[C]
8
79
12V
[B ]
11
12
GRY
LT GRN
/BLK
E52-1
E52-5
E49-1
GRNGRNWHTBLK
WHY
G28-25G28-31
RED/BLK
10
3
4
4
5 6
4
4
1 2
4
E49-2BLK
I7RS0B630003-01
[A]: Connector “E52” (viewed from harness side) 3. Junction block assembly 8. P/S control module
[B]: Connector “E49” (viewed from harness side) 4. Fuse 9. T o ECM, BCM, Air bag SDM control module and ABS control
module assembly
[C]: Connector “G28” (viewed from harness side) 5. Comb ination meter 10. Individual circuit fuse box No.1
1. Main fuse box 6. “EPS” warning light 11. Serial data circuit
2. Ignition switch 7. Date link connector (DLC)

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TroubleshootingStep Action Yes No 1 Was “EPS System Check” performed? Go to Step 2. Go to “EPS System
Check”.
2 1) Make sure that SUZUKI scan tool is free from malfunction and that correct program card (software) for
P/S system is used.
2) Turn ignition switch to OFF position.
3) Check proper connection of SUZUKI scan tool to DLC.
Is connection in good condition? Go to Step 3. Connect SUZUKI scan
tool to DLC properly.
3 1) Check if communication is possible by making communication with other controllers (ECM, BCM, ABS
or SDM) or other vehicles.
Is it possible to communic ate with the other controllers? Go to Step 4. Repair open in common
section of “serial data
circuit” (“PPL/WHT” wire
circuit) used by all
controllers or short to
ground or power circuit
which has occurred
somewhere in serial
data circuit (“PPL/WHT”
wire circuit).
4 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? Go to Step 5. Repair or replace
defective circuit.
5 1) With ignition switch turned OFF, disconnect “E52” connector from P/S control module and check for
terminal to P/S control module connector.
2) If connections are OK, check t hat “Serial data circuit” is
as following.
• Insulation resistance of “Serial data circuit” wire is infinity between its terminal and other terminals at P/S
control module connector.
• Wiring resistance of “Seria l data circuit” wire is less
than 1 Ω.
• Insulation resistance of “Serial data circuit” wire is infinity between its terminal and vehicle body ground.
Is circuit in good condition? Substitute a known-
good P/S control
module and recheck.
Repair or replace
defective circuit.

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“EPS” Warning Light Does Not Come ON with Ignition Switch Turned ON before Engine StartsS7RS0B6304010
Wiring Diagram
Circuit Description
Operation (ON/OFF) of “EPS” warning light is controlled by P/S control module through combination meter.
If the P/S system is in good condition, P/S control module turns “ EPS” warning light ON at the ignition switch ON, and
then turns it OFF at the engine start. If an abnormality in the system is detected, “EPS” warning light is turned ON
continuously by P/S control module. If P/S control module is disconnected, “EPS” warning light is not turned ON.
Troubleshooting
MBLK
REDE51-1
E51-2
[A ]
12 3
4 5 67
89
11
10
12 13
141516
17 18 19 2010 9 8 7654 3 21
16 15 14 13 12 11
26 25 24 2322 21 20 19 18 17
32 31 30 29 28 27
[C]
7
12V
E49-2BLK
[B ]
1 2
GRY
LT GRN
/BLK
E52-1
E52-5
E49-1
GRNGRNWHTBLK
WHY
G28-25G28-31
RED/BLK
8
3
4
4
5 6
4
4
1 2
4
9
I7RS0B630004-01
[A]: Connector “E52” (viewed from harness side) 2. Ignition switch6. “EPS” warning light
[B]: Connector “E49” (viewed from harness side) 3. Junction block assembly7. P/S control module
[C]: Connector “G28” (viewed from harness si de)4. Fuse 8. Individual circuit fuse box No.1
1. Main fuse box 5. Combination meter9. “EPS” warning light circuit
StepAction YesNo
1 1) Turn ignition switch ON.
Do the other warning lights come on? Go to Step 2.
“GRN”, “RED/BLK” wire
circuit or circuit fuse for
combination meter open
or short to ground.
2 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? Go to Step 3.
Repair or replace
defective circuit.
3 1) Remove combination meter and disconnect combination meter connector (“G28”) with ignition switch turned OFF.
2) Check for proper connection to the combination meter at “G28-31” terminal.
3) If OK, check voltage between “G28-31” (“RED/BLK” wire) terminal and body ground with ignition switch ON.
Is it 10 – 14 V? Go to Step 4.
“RED/BLK” wire circuit
open or short to ground.