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 1A-106 Engine General Information and Diagnosis:
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 Does fuel level meter in dicate “E” level (empty)? Add fuel and recheck. Go to Step 3.
3 Fuel quality check
1) Check that there is fuel of good quality in the fuel tank.
Is it OK? Go to Step 4.
Clean in fuel system
circuit and change fuel.
4 Ignition system check
1) Check spark plug and ignition spark of cylinder where
misfire occurs, referring to “Spark Plug Inspection in
Section 1H” and “Ignition Spark Test in Section 1H”.
Are they in good condition? Go to Step 5.
Faulty ignition coil, wire
harness, spark plug or
other system parts.
5 Fuel injector circuit check
1) Using sound scope, check each injector operating sound
at engine cranking or idling.
Do all injectors ma ke operating sound? Go to Step 6.
Check coupler
connection and wire
harness of injector not
making operating sound
and injector itself. If OK,
substitute a known-
good ECM and recheck.
6 Fuel pressure check
1) Check fuel pressure referring to “Fuel Pressure Check”.
Is check result satisfactory? Go to Step 7.
Repair or replace fuel
system.
7 Fuel injector check
1) Check fuel injector(s) re ferring to “Fuel Injector
Inspection in Section 1G”.
Is check result satisfactory? Go to Step 8.
Replace defective
injector.
8 Ignition timing check
1) Check ignition timing referring to “Ignition Timing
Inspection in Section 1H”.
Is check result satisfactory? Go to Step 9.
Check related sensors.
9 EGR system check
1) Check EGR system referring to “EGR System Inspection
in Section 1B”.
Is check result satisfactory? Go to Step 10. Repair or replace EGR
system.
10 Exhaust system check
1) Check exhaust system for exhaust gas clogged.
Is it OK? Go to Step 11. Repair clogged of
exhaust system.
Downloaded from www.Manualslib.com manuals search engine 1A-116 Engine General Information and Diagnosis:
DTC P0401 / P0402: Exhaust Gas Recirculation Flow Insufficient Detected / Excessive DetectedS7RS0B1104044
System and Wiring Diagram
I6RS0C110019-02
1. EGR valve5. Fresh air 9. Ignition switch
2. Intake manifold 6. Exhaust gas10. Main relay
3. ECM 7. “IG COIL” fuse11. “FI” fuse
4. Sensed information 8. Main fuse box12. “IG ACC” fuse
Downloaded from www.Manualslib.com manuals search engine 1A-118 Engine General Information and Diagnosis:
DTC P0403: Exhaust Gas Recirculation Control CircuitS7RS0B1104045
Wiring Diagram
Refer to “DTC P0401 / P0402: Exhaust Gas Recirculation Flow Insufficient Detected / Excessive Detected”.
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 to DLC.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it for 30 seconds.
4) Check DTC. 3
EGR valve operation check
1) With ignition switch turned OF F, install SUZUKI scan tool
to DTC.
2) Check EGR system referring to “EGR System Inspection
in Section 1B”.
Is it in good condition? Go to Step 4. Go to Step 5.
4 MAP sensor check
1) Check MAP sensor for performance referring to “MAP
Sensor Inspection in Section 1C”.
Is check result satisfactory? Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.Replace MAP sensor.
5 EGR valve control circuit check
1) Check that EGR valve control circuits are in good
condition referring to Step 2 to 5 of “DTC P0403:
Exhaust Gas Recirculation Control Circuit”
Are circuits in good condition? Go to Step 6. Repair or replace EGR
valve control circuit(s).
6 EGR valve check
1) Check EGR valve referring to “EGR Valve Inspection in
Section 1B”.
Is check result satisfactory? Go to Step 7. Faulty EGR valve.
7 MAP sensor check
1) Check MAP sensor for performance referring to “MAP
Sensor Inspection in Section 1C”.
Is check result satisfactory? EGR passage clogged.
If OK, substitute a
known-good ECM and
recheck.
Replace MAP sensor.
Step Action Yes No
DTC detecting condition
Trouble area
EGR valve output voltage is differ ent from output command with more
than one pole out of 4 poles.
(1 driving cycle detection logic) • EGR valve circuit open
•EGR valve
•ECM
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.