HO2S-1 SUZUKI SWIFT 2008 2.G Service User Guide

Downloaded from www.Manualslib.com manuals search engine 1A-36 Engine General Information and Diagnosis:
O2S B1 S1 ACT (HEATED OXYGEN SENSOR-1,
ACTIVE / INACTIVE)
This parameter indicates activation condition of HO2S-1.
ACTIVE: Activating
INACTIVE: warming up or at stop
O2S SENSOR B1 S2 (HEATED OXYGEN SENSOR-2,
V)
It indicates output voltage of HO2S-2 installed on
exhaust pipe (post-catalyst). It is used to detect catalyst
deterioration.
O2S B1 S2 ACT (HEATED OXYGEN SENSOR-2,
ACTIVE / INACTIVE)
This parameter indicates acti vation condition of HO2S-2.
ACTIVE: Activating
INACTIVE: warming up or at stop
FUEL SYSTEM (FUEL SYSTEM STATUS)
Air/fuel ratio feedback loop status displayed as one of
the followings.
OPEN: Open-loop has not yet satisfied conditions to go
closed loop.
CLOSED: Closed-loop using oxygen sensor(s) as
feedback for fuel control.
OPEN-DRIVE COND: Open-loop due to driving
conditions (Power enrichment, etc.).
OPEN SYS FAULT: Open-loop due to detected system
fault.
MAP (MANIFOLD ABSOLUTE PRESSURE, in.Hg,
kPa)
This value indicates how much correction is necessary
to keep the air/fuel mixture stoichiometrical.
It is detected by manifold absolute pressure sensor.
BAROMETRIC PRESS (kPa, in.Hg)
This parameter represents a measurement of barometric
air pressure and is used for al titude correction of the fuel
injection quantity and IAC valve control.
STEP EGR FLOW DUTY (%)
This parameter indicates opening rate of EGR valve
which controls the amount of EGR flow.
FUEL CUT (ON/OFF)
ON: Fuel being cut (output signal to injector is stopped)
OFF: Fuel not being cut
A/C PRESSURE (A/C REFRIGERANT ABSOLUTE
PRESSURE, kPa)
This parameter indicates A/C refrigerant absolute
pressure calculated by ECM.
CLOSED THROTTLE PO S (CLOSED THROTTLE
POSITION, ON/OFF)
This parameter reads ON wh en throttle valve is fully
closed, or OFF when it is not fully closed. CANIST PRG DUTY (EVAP CANISTER PURGE FLOW
DUTY, %)
This parameter indicates valve ON (valve open) time
rate within a certain set cycle of EVAP canister purge
valve which controls the amount of EVAP purge.
IGNITION ADVANCE (IGNITION TIMING ADVANCE
FOR NO.1 CYLINDER,
°)
Ignition timing of No.1 cylinder is commanded by ECM.
The actual ignition timing should be checked by using
the timing light.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage
inputted from main relay to ECM.
FUEL PUMP (ON/OFF)
ON is displayed when ECM activates the fuel pump via
the fuel pump relay switch.
ELECTRIC LOAD (ON/OFF)
ON: Headlight or small light ON signal inputted.
OFF: Above electric loads all turned OFF.
BRAKE SW (ON/OFF)
This parameter indicates the state of the brake switch.
RADIATOR COOLING FAN (RADIATOR COOLING
FAN CONTROL RELAY, ON/OFF)
ON: Command for radiator cooling fan control relay
operation being output.
OFF: Command for relay operation not being output.
BLOWER FAN (ON/OFF)
This parameter indicates the state of the blower fan
motor switch.
A/C SWITCH (ON/OFF)
ON: Command for A/C operatio n being output from ECM
to HVAC.
OFF: Command for A/C oper ation not being output.
A/C COMP RELAY (A/C COMPRESSOR RELAY, ON/
OFF)
This parameter indicates the state of the A/C switch.
VEHICLE SPEED (km/h, mph)
It is computed based on pulse signals from vehicle
speed sensor.
VVT GAP (TARGET-ACTUAL POSITION, °)
It is calculated using the formula: target valve timing
advance – actual valve timing advance.
TP SENSOR 1 VOLT (THROTTLE POSITION SENSOR
(MAIN) OUTPUT VOLTAGE, V)
The TP sensor (main) reading provides throttle valve
opening information in the form of voltage.

Downloaded from www.Manualslib.com manuals search engine 1A-54 Engine General Information and Diagnosis:
DTC P0031 / P0032: HO2S Heater Control Circuit Low / High (Sensor-1)S7RS0B1104015
Wiring Diagram
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) 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 speed for 1 min. or more.
5) 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.

E23 C37
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495051
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45 43 41 331
1213
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34
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567
1011
17
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47 46
495051
2122
52 16
25 9
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14
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57 54 53
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60 58 2
262728
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34353637
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45 43 41 331
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BLK/WHT
WHT
11
GRN
3 9
E23-29
WHT
YEL
BLK/WHT
BLKC37-46
C37-10
C37-57
6
7
10
BLK
BLUWHT
BLK/RED
4
5
8
12
1
I6RS0C110006-03
1. Main fuse box
4. Junction block assembly 7. Heater 10. To HO2S-2
2. Shield wire 5. “IG COIL” fuse8. To HO2S-2 heater 11. Individual circuit fuse box No.1
3. Ignition switch 6. HO2S-19. ECM 12. “IG ACC” fuse
DTC detecting condition Trouble area
HO2S-1 heater voltage is more than specified value or lower
than specified value for 5 seconds continuously.
(2 driving cycle detection logic) • HO2S-1 heater circuit
• HO2S-1 heater
•ECM

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-55
StepAction YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 HO2S-1 heater power circuit check
1) Disconnect connector from HO 2S-1 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-1 at “BLK/WHT” and “BLK/RED” wire terminals.
3) If wire and connection are OK, measure voltage between “BLK/WHT” wire terminal and engine ground
with ignition switch turned ON.
Is voltage over 10 V? Go to Step 3.
“BLK/WHT” wire is open
circuit or shorted to
ground circuit.
3 HO2S-1 heater power circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “BLK/WHT” wire terminal of HO2S-1 connector and “E 23-29” terminal of ECM
connector.
Is resistance below 5
Ω? Go to Step 4. “BLK/WHT” wire is high
resistance circuit.
4 HO2S-1 heater drive circuit check
1) Measure resistance between “C37-46” terminal of ECM
connector and vehicle body ground.
Is resistance infinity? Go to Step 5. “BLK/RED” wire is
shorted to ground
circuit.
5 HO2S-1 heater drive circuit check
1) Turn ON ignition switch.
2) Measure voltage between “C37-46” terminal of ECM
connector and vehicle body ground.
Is voltage 0 V? Go to Step 6. “BLK/RED” wire is
shorted to power circuit.
6 HO2S-1 heater drive circuit check
1) Connect connector to HO2S-1 with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Measure voltage between “C37-46” terminal of ECM connector and vehicle body ground with connector
disconnected from ECM.
Is voltage over 10 V? Go to Step 7. “BLK/RED” wire is open
circuit.
7 HO2S-1 heater check
1) Disconnect HO2S-1 connector with ignition switch
turned OFF.
2) Check HO2S-1 heater resistance referring to “HO2S-1 and HO2S-2 Heater On-Vehicle Inspection in Section
1C”.
Is resistance within specified value range? Go to Step 8. Replace HO2S-1.
8 HO2S-1 heater power circuit check
1) Connect connector to HO2S-1 with ignition switch turned
OFF.
2) Measure resistance between “E23-29” and “C37-46” terminals of ECM connector.
It resistance below 12
Ω? Substitute a known-
good ECM and recheck.
“BLK/WHT”, “BLK/RED”
and / or “BLK” wire is
high resistance circuit.

Downloaded from www.Manualslib.com manuals search engine 1A-56 Engine General Information and Diagnosis:
DTC P0037 / P0038: HO2S Heater Control Circuit Low / High (Sensor-2)S7RS0B1104016
Wiring Diagram
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) 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 speed for 1 min.
5) 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.

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
11
GRN
3 9
E23-29
BRN
YEL
BLK/WHT
BLKC37-47
C37-11
C37-57
6
2
7
10
BLK
BLUWHT
RED/BLU
1
4
5
8
12
5V
I6RS0C110007-01
1. Main fuse box 4. Junction block assembly 7. Heater 10. To HO2S-1
2. Shield wire 5. “IG COIL” fuse8. To HO2S-1 heater 11. Individual circuit fuse box No.1
3. Ignition switch 6. HO2S-29. ECM 12. “IG ACC” fuse
DTC detecting condition Trouble area
HO2S-2 heater voltage is more than specified value or less than
specified value for 5 seconds continuously
(2 driving cycle detection logic) • HO2S-2 heater
• HO2S-2 heater circuit
•ECM

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-57
StepAction 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 heater power circuit check
1) Disconnect connector from HO 2S-2 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-2 at “BLK/WHT” and “RED/BLU” wire terminals.
3) If wire and connection are OK, measure voltage between “BLK/WHT” wire terminal of HO2S-2 connector
and engine ground with ignition switch turned ON.
Is voltage over 10 V? Go to Step 3.
“BLK/WHT” wire is open
circuit or shorted to
ground circuit.
3 HO2S-2 heater power circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “BLK/WHT” wire terminal of HO2S-2 connector and “E23-29” terminal wire of ECM
connector.
Is resistance below 5
Ω? Go to Step 4. “BLK/WHT” wire is high
resistance circuit.
4 HO2S-2 heater drive circuit check
1) Measure resistance between “RED/BLU” wire terminal of
HO2S-2 connector and vehicle body ground.
Is resistance infinity? Go to Step 5. “RED/BLU” wire is
shorted to ground
circuit.
5 HO2S-2 heater drive circuit check
1) Turn ON ignition switch.
2) Measure voltage between “RED/BLU” wire terminal of
HO2S-2 connector and vehicle body ground.
Is voltage 0 V? Go to Step 6. “RED/BLU” wire is
shorted to power circuit.
6 HO2S-2 heater drive circuit check
1) Connect connector to HO2S-2 with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Measure voltage between “C37-47” terminal of disconnected ECM connector and vehicle body ground.
Is voltage over 10 V? Go to Step 7.
“RED/BLU” wire is open
circuit.
7 HO2S-2 heater check
1) Disconnect HO2S-2 connector with ignition switch
turned OFF.
2) Check HO2S-2 heater resistance referring to “HO2S-1 and HO2S-2 Heater On-Vehicle Inspection in Section
1C”.
Is resistance within specified value? Go to Step 8.
Replace HO2S-2.
8 HO2S-2 heater power circuit check
1) Connect connector to HO2S-2 with ignition switch turned
OFF.
2) Measure resistance between “E23-29” and “C37-47” terminals of ECM connector.
Is resistance below 30
Ω? Substitute a known-
good ECM and recheck.
“RED/BLU” wire is high
resistance circuit.

Downloaded from www.Manualslib.com manuals search engine 1A-88 Engine General Information and Diagnosis:
DTC P0131 / P0132: O2 Sensor (HO2S) Circuit Low Voltage / High Voltage (Sensor-1)S7RS0B1104031
Wiring Diagram
DTC Detecting Condition and Trouble Area
E23C37
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
11
GRN
3 9
E23-29
WHT
YEL
BLK/WHT
BLKC37-46
C37-10
C37-57
6
7
10
BLK
BLUWHT
BLK/RED
4
5
8
12
1
I6RS0C110006-03
1. Main fuse box
4. Junction block assembly 7. Heater 10. To HO2S-2
2. Shield wire 5. “IG COIL” fuse8. To HO2S-2 heater 11. Individual circuit fuse box No.1
3. Ignition switch 6. HO2S-19. ECM 12. “IG ACC” fuse
DTC detecting condition Trouble area
DTC P0131:
Maximum HO2S voltage is less than 0.6 V
(*2 driving cycle detection logic, monitoring once per driving cycle)
DTC P0132:
Minimum HO2S voltage is 0.3 V or more
(*2 driving cycle detection logic, monitoring once per driving cycle) • HO2S-1 circuit
•HO2S-1
• Fuel system
•ECM
• Fuel shortage
• Exhaust system
• Air intake system

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-89
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) Drive vehicle at 40 mph (60 km/h) or higher. (engine speed: 2500 – 3000 r/min.)
5) Keep above vehicle speed for 6 min. or more. (Throt tle valve opening is kept constant in this step.)
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting (with fuel cut for 3 sec. or more)
and then stop vehicle.
7) 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 HO2S-1? Go to applicable DTC
diag. flow.Go to Step 3.
3 HO2S-1 signal 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-1 output voltage deflect between below 0.3 V
and over 0.6 V repeatedly? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”. If check result is
OK, go to Step 9.
Go to Step 4.

Downloaded from www.Manualslib.com manuals search engine 1A-90 Engine General Information and Diagnosis:
4HO2S-1 ground check
1) Disconnect connector from HO 2S-1 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-1 connector at “BLK/RED”, “WHT”, “BLK /WHT” and “YEL” wire
terminals.
3) If connections are OK, m easure resistance between
“YEL” wire terminal of HO2S-1 connector and engine
ground.
Is measured 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 “WHT” wire terminal of HO2S-1 connector and “C37-10” terminal of ECM
connector.
Is resistance less than 5
Ω? Go to Step 6. “WHT” wire is high
resistance circuit or
open circuit. Poor “C37-
10” terminal connection.
Faulty ECM ground. If
they are OK, substitute
a known-good ECM and
recheck.
6 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turn OFF.
2) Measure resistance between “WHT” wire terminal of HO2S-1 connector and vehicle body ground.
Is resistance infinity? Go to Step 7. “WHT” wire is shorted to
ground circuit.
7 HO2S-1 signal circuit check
1) Measure voltage between “WHT” wire terminal of HO2S-
1 connector and vehicle body ground.
Is voltage 0 V? Go to Step 8. “WHT” wire is shorted to
other circuit.
8 HO2S-1 heater circuit check
1) Check HO2S-1 heater circuit referring to “DTC P0031 /
P0032: HO2S Heater Control Circuit Low / High
(Sensor-1)”.
Is circuit in good condition? Go to Step 9. Repair HO2S-1 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-1 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-91
DTC P0133: O2 Sensor (HO2S) Circuit Slow Response (Sensor-1)S7RS0B1104032
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) Drive vehicle at 40 mph (60 km/h) or higher. (engine speed: 2500 – 3000 r/min.)
5) Keep above vehicle speed for 6 min. or more. (Throt tle valve opening is kept constant in this step.)
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting (with fuel cut for 3 sec. or more)
and then stop vehicle.
7) Check if DTC and pending DTC exist by using scan tool. If not, check if oxygen sensor monitoring test has been
completed by using scan tool. If not in both of above c hecks (i.e., no DTC and pending DTC and oxygen sensor
monitoring test not completed), check vehicle cond ition (environmental) and repeat Step 3) through 6).
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 time (time to change from lean to rich or from rich to lean) of HO2S-1 output
voltage is about 1 sec. at minimum or aver age time of 1 cycle is 5 sec. at minimum.
(*2 driving cycle detection logic, monitoring once per driving cycle) Heated oxygen sensor-1
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 HO2S-1 (DTC P0133)? Go to applicable DTC
diag. flow.Replace HO2S-1.

Downloaded from www.Manualslib.com manuals search engine 1A-92 Engine General Information and Diagnosis:
DTC P0134: O2 Sensor (HO2S) Circuit No Activity Detected (Sensor-1)S7RS0B1104033
Wiring Diagram
Refer to “DTC P0131 / P0132: O2 Sensor (HO2S) Circuit Low Voltage / High Voltage (Sensor-1)”
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) Drive vehicle at 40 mph (60 km/h) or higher. (engine speed: 2500 – 3000 r/min.)
5) Keep above vehicle speed for 6 min. or more. (Throt tle valve opening is kept constant in this step.)
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting (with fuel cut for 3 sec. or more)
and then stop vehicle.
7) Check if DTC and pending DTC exist by using scan tool. If not, check if oxygen sensor monitoring test has been
completed by using scan tool. If not in both of above c hecks (i.e., no DTC and pending DTC and oxygen sensor
monitoring test not completed), check vehicle cond ition (environmental) and repeat Step 3) through 6).
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 voltage is higher than 0.6 V for more than 1 min
continuously after warming up engine or HO2S voltage is lower
than 0.3 V for more than 1 min continuously after warming up
engine.
(2 driving cycle detection logic) •HO2S-1
• HO2S-1 circuit
• Exhaust gas leakage
•ECM
• 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”.