2008 SUZUKI SWIFT IDLE SPEED CONTROL

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DTC Confirmation Procedure
WARNING!
• When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out by 2 persons, a driver and a tester, on a level road.

NOTE
Check to make sure that following conditions ar e satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10 °C (14 ° F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine Coolant temperature: 70 °C (158 °F) to 150 °C (302 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Increase vehicle speed to 70 – 80 km/h (43 – 50 mile/h) at 5th gear or D range.
5) Release accelerator pedal and with engine brake applied, ke ep vehicle coasting (with fuel cut for 4 sec. or more),
then stop vehicle and run engine at idle speed for 60 sec. or more.
6) Repeat Step 4).
7) Keep above vehicle speed for 8 min. or more. (Throt tle valve opening is kept constant in this step.)
8) Repeat Step 5).
9) Check DTC and pending DTC.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.

Step Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Is there DTC(s) other than fuel system (DTC P0171 / P0172)
and HO2S-2 (DTC P0140)? Go to applicable DTC
diag. flow.Go to Step 3.
3 HO2S-2 and its circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Warm up engine to normal operating temperature and keep it at 2000 r/min. for 60 sec.
3) Repeat racing engine (Repeat depressing accelerator pedal 5 to 6 times continuous ly to enrich A/F mixture and
take foot off from pedal to enlean it).
Does HO2S-2 output voltage indicate deflection between
over 0.35 V and below 0.25 V? Go to “DTC P0171 /
P0172: Fuel System
Too Lean / Rich”.
Go to Step 4.

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DTC P0140: O2 Sensor (HO2S) Circuit No Activity Detected (Sensor-2)S7RS0B1104035
Wiring Diagram
Refer to “DTC P0137 / P0138: O2 Sensor (HO2S) Circuit Low Voltage / High Voltage (Sensor-2)”
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
WARNING!
• When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out by 2 persons, a driver and a tester, on a level road.

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Increase vehicle speed to 60 – 80 km/h (37 – 50 mile/h) at 5th gear or D range.
5) Release accelerator pedal and with engine brake applied, ke ep vehicle coasting (with fuel cut for 4 sec. or more),
then stop vehicle and run engine at idle speed for 60 sec. or more.
6) Check DTC and pending DTC.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.

DTC detecting condition Trouble area
HO2S-2 voltage is higher than specified value after warming up engine
(circuit open).
(2 driving cycle detection logic) •HO2S-2
• HO2S-2 circuit
•ECM
• Exhaust gas leakage
• Air intake system
Step
Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 HO2S-2 ground check
1) Disconnect connector from HO 2S-2 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-2 connector at “RED/BLU”, “BRN”, “YEL” and “BLK/WHT” wire
terminals.
3) If connections are OK, m easure resistance between
“YEL” wire terminal of HO2S-2 connector and engine
ground.
Is resistance less than 5
Ω? Go to Step 3. “YEL” wire is open or
high resistance circuit.
Poor “C37-57” terminal
connection. Faulty ECM
ground.
If they are OK,
substitute a known-
good ECM and recheck.

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DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
WARNING!
• When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out by 2 persons, a driver and a tester, on a level road.

NOTE
Check to make sure that following conditions ar e satisfied when using this “DTC confirmation
procedure”.
• Intake air temperature at engine start: –10 °C (14 ° F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine coolant temperature: 70 °C (158 °F) to 150 °C (302 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Run engine at idle for 10 min.
5) Drive vehicle and increase engine speed 3000 rpm in 3rd gear.
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting for 5 sec. or more. (Keep fuel cut condition for 5 sec. or more) If fuel cut condition is not ke pt for 5 sec. or more, coast down a slope in engine speed
1000 – 3000 rpm for 5 sec. or more.
7) Stop vehicle and run engine at idle.
8) Check DTC and pending DTC by using scan tool.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.

DTC detecting condition Trouble area
DTC P0401:
Difference in intake manifold absolute pressure between opened EGR valve
and closed EGR valve is smaller than specified value.
(*2 driving cycle detection logic, monitoring once per driving cycle)
DTC P0402:
Difference in intake manifold absolute pressure between opened EGR valve
and closed EGR valve is la rger than specified value.
(*2 driving cycle detection logic, monitoring once per driving cycle) •EGR valve
• EGR passage
• MAP sensor
•ECM
Step
Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Do you have SUZUKI scan tool? Go to Step 3.Go to Step 5.

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DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) Turn OFF ignition switch.
2) Clear DTC with ignition switch turned ON.
3) Run engine at idle speed.
4) Check DTC.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.

DTC detecting condition Trouble area
Monitor signal of radiator cooling fan relay is different from
command signal.
(1 driving cycle detection logic) • Radiator cooling fan relay circuit malfunction
• Radiator cooling fa
n relay malfunction
• ECM malfunction
Step Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Circuit fuse check
1) Check “RDTR FAN” fuse (1) in individual circuit fuse box
No.1 with ignition switch turned OFF.
Is “RDTR FAN” fuse in good condition? Go to Step 3.
Check for short in
circuits connected to
this fuse.
1
I4RS0A110022-01

Downloaded from www.Manualslib.com manuals search engine 1A-138 Engine General Information and Diagnosis:
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool to DLC
2) Turn ON ignition switch and clear DTC.
3) Make sure that all accessory switches are tuned OFF.
4) Start engine and warm it up to normal operating temperature (ECT approx. 90 – 95 °C, 193 – 203 °F).
5) Turn ON the followi ng accessory switches.
• Head light switch.
• Blower motor switch (max position).
• Rear defogger switch.
6) Increase engine speed to 4000 rpm and keep it for 10 sec or more.
7) Decrease engine speed to idle.
8) Check DTC.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.

DTC detecting condition Trouble area
• Battery voltage is higher than specification even through generator control is maximum regulation (duty 100%).
• Battery voltage is lower than specification even through generator control is minimum regulation (duty 0%) and electric
load is less than 15 A.
(1 driving cycle detection logic but MIL does not light up) • Generator and/or its circuit
• Electric load current sensor
•ECM
• Generator drive belt
Step
Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Generator drive belt check
1) Check generator drive belt tension referring to “Water
Pump / Generator Drive Belt Tension Inspection and
Adjustment in Section 1J”.
Is check result satisfactory? Go to Step 3.
Adjust or replace
generator drive belt.

Downloaded from www.Manualslib.com manuals search engine 1A-140 Engine General Information and Diagnosis:
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool to DLC.
2) Turn ON ignition switch and clear DTC.
3) Make sure that all accessory switch is tuned OFF.
4) Start engine and warm it up to normal operating temperature (ECT approx. 90 – 95 °C, 193 – 203 °F).
5) Turn ON following accessory switch. • Head lights switch.
• Blower motor switch (max position).
• Rear defogger switch.
6) Increase engine speed to 4000 rpm and keep it for 10 sec. or more.
7) Decrease engine speed to idle.
8) Check DTC.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.

Step Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Generator control circuit check
1) Disconnect connector from generator and ECM with
ignition switch turned OFF.
2) Check for proper connection of wire terminal to generator connector and to ECM connector.
3) If connections are OK, check generator control (generator “C” terminal) circuit and field coil monitor
(generator “FR” terminal) circuit for the following.
• Resistance of each generato r control wire and field
coil monitor wire between generator connector and
ECM connector is less than 1 Ω (continuity check)
• Resistance between generator control wire and field coil monitor wire of generator connector is infinity
(insulation check)
• Resistance between each generator control wire and field coil monitor wire of generator connector and
vehicle body ground is infinity (ground circuit short
check)
• Voltage between each generator control wire and field
coil monitor wire of generator connector and vehicle
body ground is 0 V with ignition switch tuned ON
(power circuit short check)
Are they in good condition? Go to Step 3.
Repair or replace
defective wire.
3 Generator check
1) Check for generator output referring to “Generator Test
(Undercharged Battery Check) in Section 1J” and
“Generator Inspection in Section 1J”.
Is check result satisfactory? Substitute a known
good ECM and recheck.
Repair or replace
generator.

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DTC P1501 / P1502: Electric Load Current Sensor Circuit Low / HighS7RS0B1104059
System and Wiring Diagram
Electric Load Current Sensor Description
Refer to “Generator Control System Description”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool to DLC.
2) Turn ON ignition switch and clear DTC.
3) Make sure that all accessory switch is tuned OFF.
4) Start engine and warm it up to normal operating temperature (ECT approx. 90 – 95 °C, 193 – 203 °F).
5) Increase engine speed to 3000 rpm.
6) In this state, Turn ON following accessory switch.
• Head lights switch.
• Blower motor switch (max position).
• Rear defogger switch.
7) Decrease engine speed to idle.
8) Check DTC.
E23 C37
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
BLK/WHT
WHT
GRN
4
3 2
E23-29
1
C37-23PNK/BLU
BLK/ORN
BLK/WHT
I5RS0C110014-01
1. Electric load current sensor
3. “IG COIL” fuse
2. ECM 4. Ignition switch
DTC detecting condition Trouble area
P1501:
Electric load current is lower th an specified value (electric load
current sensor voltage is higher than specified value).
(1 driving cycle detection logic but MIL does not light up)
P1502:
Electric load current is higher than specified value (electric load
current sensor voltage is lo wer than specified value).
(1 driving cycle detection logic but MIL does not light up) • Electric load current sensor and/or its circuit
•ECM

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DTC P1510: ECM Back-Up Power Supply MalfunctionS7RS0B1104060
Wiring Diagram
Circuit Description
Battery voltage is supplied so that DTC memory, values for engine control learned by ECM, etc. are kept in ECM even
when the ignition switch is turned OFF.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC using scan tool and run engine at idle speed for 1 min.
3) Check DTC.
E23 C37
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
WHT/REDWHT80A
50A
3
2 1
E23-2
I4RS0A110051-01
1. ECM
2. “RADIO” fuse 3. Main fuse box
DTC detecting condition Trouble area
Back-up power circuit voltage is less than 70% battery voltage for
5 seconds continuously while engine is running.
(1 driving cycle detection logic) Battery voltage supply circuit