2008 SUZUKI SWIFT HO2S-2

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 1A-96 Engine General Information and Diagnosis:
4HO2S-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 5. “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.
5 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 6. “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.
6 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “BRN” wire terminal of HO2S-2 connector and vehicle body ground.
Is resistance infinity? Go to Step 7. “BRN” wire is shorted to
ground circuit.
7 HO2S-2 signal circuit check
1) Measure voltage between “BRN” wire terminal of HO2S-
2 connector and vehicle body ground.
Is voltage 0 V? Go to Step 8. “BRN” wire is shorted to
other circuit.
8 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 9. Repair HO2S-2 circuit.
9 Exhaust system check
1) Check exhaust system for exhaust gas leakage.
Is it OK? Go to Step 4 in “DTC
P0171 / P0172: Fuel
System Too Lean /
Rich”.
If it is in good condition,
go to Step 10.Repair leakage of
exhaust system.
10 Air intake system check
1) Check air intake system for clog or leak.
Is it OK? Check HO2S-2 referring
to “HO2S-1 and HO2S-
2 Heater On-Vehicle
Inspection in Section
1C”.
If it is in good condition,
substitute a known-
good ECM and recheck.Repair or replace air
intake system.
Step Action Yes No

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 1A-120 Engine General Information and Diagnosis:
DTC P0420: Catalyst System Efficiency below ThresholdS7RS0B1104046
System and Wiring Diagram
Circuit Description
ECM monitors oxygen concentration in the exhaust gas which has passed the warm up three way catalytic converter
by HO2S-2. When the catalyst is functioning properly, the variation cycle of HO2S-2 output voltage (oxygen
concentration) is slower than that of HO2S-1 output voltage because of the amount of oxygen in the exhaust gas
which has been stored in warm up three way catalytic converter.
Reference
Oscilloscope waveforms
C37-11
C37-10
C37-57
WHT
BRN
1
3 2
4
5 VYELYEL
BLUWHTBLUWHT 5
I4RS0A110037-01
1. HO2S-1
3. Warm up three way catalytic converter 5. ECM
2. HO2S-2 4. Three way catalytic converter
I2RH01110102-01

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-122 Engine General Information and Diagnosis:
DTC P0443: Evaporative Emission System Purge Control Valve CircuitS7RS0B1104047
Wiring Diagram
DTC Detecting Condition and Trouble Area3
HO2S-2 output voltage check
1) Check output voltage of HO2S-2 referring to “DTC
P0137 / P0138: O2 Sensor (HO2S) Circuit Low Voltage /
High Voltage (Sensor-2)” and “DTC P0137 / P0138: O2
Sensor (HO2S) Circuit Low Voltage / High Voltage
(Sensor-2)”.
Is check result satisfactory? Replace exhaust
manifold (built in warm
up three way catalytic
converter) and exhaust
center pipe (built in
three way catalytic
converter).
Check “BRN” and / or
“YEL” wires for open
and short, and
connections for poor
connection.
If wires and connections
are OK, replace HO2S-
2.
Step Action Yes No
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 33 1
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 48 32 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
BLK/WHT
BLK/RED
BLK/RED
WHTBLK/YELBLK/YEL
BLK/YEL
GRN
BRN/WHT
12V 5V
5
4 2
3 6E23-29
E23-1
E23-60
C37-58
C37-15 C37-30
BLK/ORN
BLKBLKE23-31 BLK
7
8
BLK/REDBLK/REDE23-16
1
C37-29 BLU/BLK
I6RS0C110020-02
1. EVAP canister purge valve
4. Main fuse box7. “FI” fuse
2. Main relay 5. Ignition switch8. “IG ACC” fuse
3. “IG COIL” fuse 6. ECM
DTC detecting conditionTrouble area
Monitor signal of EVAP canister purge valve is different from
command signal. (Circuit open or short)
(2 driving cycle detection logic) • EVAP canister purge valve
• EVAP canister purge valve circuit
•ECM

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-177
C37-10 WHTOxygen signal of
HO2S-1 0 – 1 V Ignition switch turned ON.
—
*Deflects between
over 0.5 V and under 0.45 V
(“Reference
waveform No.10: ” and “Reference
waveform No.11: ”) While engine running at
2,000 r/min. for 1 min. or
longer after warmed up.
C37-11 BRN Oxygen signal of
HO2S-2 4 – 5 V Ignition switch turned ON.
—
*Deflects between
over 0.5 V and under 0.45 V
(“Reference
waveform No.12: ”) While engine running at
2,000 r/min. or more after
vehicle running over 30
km/h, 19 mph for 5 min.
C37-12 WHT CAN (low)
(communication
line (active low
signal) to TCM (A/T
model) *0.5 – 2.5 V
(“Reference
waveform No.13: ”) Ignition switch turned ON
with engine stop. CAN communication line
signal is pulse. Pulse
signal displayed with a
regular frequency which
varies depending on
engine condition.
C37-13 RED CAN (high)
communication line
(active high signal)
to TCM (A/T
model) *2.5 – 4.5 V
(“Reference
waveform No.13: ”)
C37-14 GRY/
RED Output of 5 V
power source for
MAP sensor, A/C
refrigerant
pressure sensor
4.5 – 5.5 V Ignition switch turned ON. —
C37-15 BLK Ground for ECM Below 0.3 V Ignition switch turned ON. —
C37-16 BLU/
RED Fuel injector No.3
output 10 – 14 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
10 – 14 V
(“Reference
waveform No.1: ” and
“Reference waveform No.14: ”) Engine running at idle
after warmed up engine.
Output signal is active low
pulse. Pulse frequency
varies depending on
engine speed.
C37-17 BLU/
ORNFuel injector No.4
output 10 – 14 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
10 – 14 V
(“Reference
waveform No.1: ” and
“Reference waveform No.15: ”) Engine running at idle
after warmed up engine.
Output signal is active low
pulse. Pulse frequency
varies depending on
engine speed.
C37-18 BRN/
YEL EGR valve
(stepper motor coil
4) output 10 – 14 V Ignition switch turned ON. —
*0 – 1 V ↑↓
10 – 14 V
(“Reference
waveform No.4: ”) Ignition switch is turned to
ST (cranking) position. Output signal is active low
duty pulse. Number of
pulse generated times
varies depending on
vehicle condition.
C37-19 WHT/
RED EGR valve
(stepper motor coil
3) output 10 – 14 V Ignition switch turned ON. —
*0 – 1 V ↑↓
1

0 – 14 V
(“Reference
waveform No.4: ”) Ignition switch is turned to
ST (cranking) position. Output signal is active low
duty pulse. Number of
pulse generated times
varies depending on
vehicle condition.
Terminal
No. Wire
color Circuit Normal voltage
ConditionRemarks