2008 SUZUKI SWIFT Air intake temperature

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-95
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.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-97
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.

Downloaded from www.Manualslib.com manuals search engine 1A-98 Engine General Information and Diagnosis:
DTC P0171 / P0172: Fuel System Too Lean / RichS7RS0B1104036
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: 40 °C (104 °F) to 120 °C (248 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

3 Wire circuit check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Measure resistance between “BRN” wire terminal of HO2S-2 connector and “C37-11” terminal of ECM
connector.
Is resistance less than 5
Ω? Go to Step 4. “BRN” wire is high
resistance circuit or
open circuit. Poor “C37-
11” terminal connection.
If they are OK,
substitute a known-
good ECM and recheck.
4 HO2S-2 signal circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure voltage between “BRN” wire terminal of HO2S- 2 connector and vehicle body ground.
Is voltage 0 V? Go to Step 5. “BRN” wire is shorted to
other circuit.
5 HO2S-2 heater circuit check
1) Check HO2S-2 heater circuit referring to “DTC P0037 /
P0038: HO2S Heater Control Circuit Low / High
(Sensor-2)”.
Is circuit in good condition? Go to Step 6. Repair HO2S-2 circuit. If
circuit is OK, substitute
a known-good ECM and
recheck.
6 HO2S-2 check
1) Check HO2S-2 referring to “HO2S-1 and HO2S-2
Heater On-Vehicle Inspection in Section 1C”.
Is it in good condition? Substitute a known-
good ECM and recheck.
Replace HO2S-2.
Step Action Yes No
DTC detecting condition
Trouble area
DTC P0171:
Total fuel trim is higher than 35% or short term fuel trim is higher
than 20% for more than 1 min. continuously.
(2 driving cycle detection logic)
DTC P0172:
Total fuel trim is lower than –35% or short term fuel trim is lower
than –20% for more than 1 min. continuously.
(2 driving cycle detection logic) • Vacuum leakage
• Exhaust gas leakage
• Fuel pressure out of specification
• Fuel injector malfunction
• Heated oxygen sensor-1 malfunction
• MAF sensor malfunction
• ECT sensor malfunction

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-99
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and print Freeze Frame Data or write them down using scan tool.
3) Clear DTC using scan tool.
4) Start engine and warm up to normal operating temperature.
5) Operate vehicle with condition as noted freeze frame data for 5 min.
6) Stop vehicle and 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)? Go to applicable DTC
diag. flow.Go to Step 3.
3 Intake system and exhaust system for leakage check
Are intake system and exhaust system in good condition? Go to Step 4.
Repair or replace
defective part.
4 Fuel pressure check
1) Check fuel pressure referring to “Fuel Pressure Check”.
Is check result satisfactory? Go to Step 5.
Repair or replace
defective part.
5 Fuel injectors and its circuit check
1) Check fuel injectors referring to “Fuel Injector Inspection
in Section 1G”.
Is check result satisfactory? Go to Step 6.
Faulty injector(s) or its
circuit.
6 Visual inspection
1) Check MAF sensor and air intake system.
• Objects which block measur ing duct and resistor of
MAF sensor.
• Other air flow which does not pass MAF sensor.
Are they in good condition? Go to Step 7.
Repair or replace
defective part.
7 MAF sensor for performance check
1) With ignition switch turn ed OFF, install scan tool.
2) Start engine and warm up to normal operating temperature.
3) Check MAF value using scan tool (Refer to “Scan Tool Data” for normal value.).
Is each value within specified range? Go to Step 8.
Go to “DTC P0101:
Mass or Volume Air
Flow Circuit Range /
Performance”.
8 ECT sensor for performance check
1) Check ECT sensor referring to Step 3 and 4 of “DTC
P0118: Engine Coolant Temperature Circuit High”.
Is check result satisfactory? Go to Step 9.
Faulty ECT sensor or its
circuit.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-105
DTC P0300 / P0301 / P0302 / P0303 / P0304: Random / Multiple Cylinder Misfire Detected / Cylinder 1
/ Cylinder 2 / Cylinder 3 / Cylinder 4 Misfire Detected
S7RS0B1104039
System Description
ECM measures the angle of the crankshaft based on the pulse signal from the CKP sensor and CMP sensor for each
cylinder. If it detects a large change in the angle speed of the crankshaft, it concludes occurrence of a misfire. When
the number of misfire is counted by ECM beyond the DTC de tecting condition, it determines the cylinder where the
misfire occurred and output it as DTC.
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 temp.: –10 °C, 14 °F or higher
• 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 print Freeze Frame Data or write them down using scan tool.
3) Clear DTC using scan tool.
4) Drive vehicle under freeze frame data condition as noted for 1 min. or more.
5) Stop vehicle and check DTC and pending DTC. 11
Electric throttle body check
1) Check TP sensor referring to “Throttle Position Sensor
Performance Check” under “Electric Throttle Body
Assembly On-Vehicle Inspection in Section 1C”.
Is output voltage within specified value? Substitute a known-
good ECM and recheck.
Replace electric throttle
body.
Step Action Yes No
DTC detecting condition
Trouble area
DTC P0300:
• Misfire, which causes catalyst to overheat during 200 engine revolutions, is detected at 2 or more cylinders. (MIL flashes as lo ng as this misfire occurs continuously.)
or
• Misfire, which affects exhaust emission adv ersely during 1000 engine revolution, is
detected at 2 or more cylinders. (2 driving cycle detection logic) • Ignition system
• Fuel injector and its circuit
• Fuel pressure
• EGR system
• Abnormal air drawn in
• Engine compression
• Valve lash adjuster
• Valve timing
• Fuel shortage
• Exhaust system
• Fuel of poor quality
DTC P0301, P0302, P0303, P0304:
• Misfire, which causes catalyst to overheat during 200 engine revolutions, is detected
at 1 cylinder. (MIL flashes as long as this misfire occurs continuously.)
or
• Misfire, which affects exhaust emission adv ersely during 1000 engine revolution, is
detected at 1 cylinder. (2 driving cycle detection logic)

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-117
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.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-121
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 temp.: 70 °C, 158 °F to 150 °C (302 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (500 mmHg, 75 kPa or more)

1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Increase vehicle speed to 37 – 62 mph, 60 – 100 km/h. (engine speed: 2500 – 3000 r/min.)
4) Keep above vehicle speed for 10 min. or more (Thr ottle valve opening is kept constant in this step).
5) Stop vehicle and check if DTC / pending DTC exists using sc an tool. If not, check if catalyst monitoring test has
been completed using scan tool. If not in both of above checks (i.e., no DTC / pending DTC and catalyst
monitoring test not completed), check vehicle cond ition (environmental) and repeat Step 3) through 5).
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
Response delay of HO2S-2 signal (shifting delay from rich to lean and
from lean to rich with threshold at 0.45 V) compared to switching cycle
(rich-lean) of A/F feed back is less than specified while vehicle is
running at constant speed and except with high engine load after
warmed up.
(*2 driving cycle detection logic, monitoring once per driving cycle) • Exhaust gas leak
• Warm up three way catalytic converter
malfunction
• HO2S-2 malfunction
• HO2S-1 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 Exhaust system visual check
1) Check exhaust system for leaks, damage and loose
connection.
Is it in good condition? Go to Step 3.
Repair or replace
defective part.

Downloaded from www.Manualslib.com manuals search engine 1A-216 Engine General Information and Diagnosis:
Repair Instructions
Idle Speed and IAC Throttle Valve Opening
Inspection
S7RS0B1106001
Before idle speed check, make sure of the following.
• Lead wires and hoses of electronic fuel injection and engine and emission control systems are connected
securely.
• Valve lash is checked according to maintenance schedule.
• Ignition timing is within specification.
• All accessories (wipers, heater, lights, A/C, etc.) are out of service.
• Air cleaner has been properly installed and is in good condition.
• No abnormal air drawn in from air intake system.
After all items are confirmed, check idle speed and IAC
duty as follows.
NOTE
Before starting engine, place transmission
gear shift lever in “Neutral” (shift selector
lever to “P” range for A/T vehicle), and set
parking brake and block drive wheels.

1) Connect SUZUKI scan tool to DLC (1) with ignition
switch turned OFF.
Special tool
(A): SUZUKI scan tool 2) Warm up engine to normal operating temperature.
3) Check engine idle speed and “IAC throttle opening”
by using “Data List” mode on scan tool to check “IAC
throttle opening”.
4) If check result is out of sp ecification, inspect electric
throttle body assembly referring to “Electric Throttle
Body Assembly On-Vehicle Inspection in Section
1C”.
Engine idle speed
A/C OFF: 700 ± 50 rpm (IAC duty: 5 – 55%)
A/C ON: 850 ± 50 rpm
5) Check that specified engine idle speed is obtained with A/C turned ON if vehi cle is equipped with A/C.
If not, check A/C system.
(A)
1
I4RS0B110093-01