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 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 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 Engine General Information and Diagnosis: 1A-119
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 Description”.
2 EGR valve power supply circuit check
1) Remove air intake pipe.
2) With ignition switch turned OFF, disconnect EGR valve
connector.
3) With ignition switch turned ON, measure voltage between “BLK/RED” wire terminal of EGR valve
connector and vehicle body ground.
Is check voltage 10 – 14 V? Go to Step 3.
“BLK/RED” wire is open
circuit.
3 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Turn ON ignition switch.
3) Measure voltage between engine ground and each “GRN/RED”, “GRN/ORN”, “W HT/RED”, “BRN/YEL” wire
terminals of EGR valve connector.
Is each voltage 0 V? Go to Step 4.
Faulty wire(s) are
shorted to other circuit.
If wires are OK,
substitute a known-
good ECM and recheck.
4 Wire circuit check
1) With ignition switch turned OFF, measure resistance
between engine ground and each “GRN/RED”, “GRN/
ORN”, “WHT/RED”, “BRN/YEL” wire terminals of EGR
valve connector.
Is resistance infinity? Go to Step 5.
Faulty wire(s) are
shorted to ground
circuit.
If wires are OK,
substitute a known-
good ECM and recheck.
5 Short circuit check for EGR valve control circuit
1) With ignition turned OFF, measure resistance between
each EGR valve control circ uit wire (“GRN/RED”, “GRN/
ORN”, “WHT/RED” and “BRN/ YEL” wire) and each EGR
valve control circuit wire.
Is each resistance infinity? Go to Step 6.
Faulty wire(s) are short
circuit.
6 EGR valve stepper motor coil circuit check
1) With ignition switch turned OFF, connect EGR valve
connector.
2) Measure resistance between “E23-1/16” and each “C37- 4”, “C37-3”, “C37-19”, “C37-18” terminals of ECM
connector.
Is each resistance 20 – 31
Ω at 20 °C, 68 °F? Faulty ECM. Substitute
a known-good ECM and
recheck.
Go to Step 7.
7 EGR valve check
1) Check EGR valve resistance referring to “EGR Valve
Inspection in Section 1B”.
Is resistance within specified value? Faulty wire(s) are open
or high resistance
circuit. If wires are OK,
substitute a known-
good ECM and recheck.Faulty EGR valve.
Downloaded from www.Manualslib.com manuals search engine 1A-176 Engine General Information and Diagnosis:
Terminal No. Wire
color Circuit Normal voltage Condition Remarks
C37-1 BLU/
YEL Fuel injector No.1
output 10 – 14 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
10 – 14 V
(“Reference
waveform No.1: ”,
“Reference waveform No.2: ” and
“Reference waveform No.22: ”) Engine running at idle
after warmed up engine.
Output signal is active low
pulse. Pulse frequency
varies depending on
engine speed.
C37-2 BLU/
WHT Fuel injector No.2
output 10 – 14 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
10 – 14 V
(“Reference
waveform No.1: ” and
“Reference waveform No.3: ”) Engine running at idle
after warmed up engine.
Output signal is active low
pulse. Pulse frequency
varies depending on
engine speed.
C37-3 GRN/
ORN EGR valve
(stepper motor coil
2) 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.
C37-4 GRN/
RED EGR valve
(stepper motor coil
1) 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.
C37-5 GRN/
WHT Ignition coil No.2
and No.3 output 0 – 0.6 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
3 – 5 V
(“Reference
waveform No.5: ” and
“Reference waveform No.6: ”) Engine running at idle
after warmed up engine.
Output signal is active
high pulse. Pulse
frequency varies
depending on engine
speed.
C37-6 GRN/
YEL Ignition coil No.1
and No.4 output 0 – 0.6 V Ignition switch turned ON. —
*0 – 0.6 V ↑↓
3 – 5 V
(“Reference
waveform No.6: ”,
“Reference waveform No.7: ” and
“Reference waveform No.22: ”
)Engine running at idle
after warmed up engine.
Output signal is active
high pulse. Pulse
frequency varies
depending on engine
speed.
C37-7 — —— — —
C37-8 BRN/
WHT Generator field coil
monitor signal 10 – 14 V Ignition switch turned ON.
Signal is duty pulse. Duty
ratio varies depending on
vehicle condition.
*0 – 1 V
↑↓
10 – 14 V
(“Reference
waveform No.8: ”) Engine running at idle
after warmed up engine.
C37-9 — —— — —
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
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-185
Reference waveform No.2
No.1 fuel injector signal (2) with engine idling
Reference waveform No.3
No.2 fuel injector sig nal (2) with engine idling Reference waveform No.4
EGR valve signal
Reference waveform No.5
Ignition coil No.2 and No.3 signal (2) with engine idling
Measurement
terminal
CH1: “C37-20” to “C37-58”
CH2: “C37-1” to “C37-58”
Oscilloscope
setting CH1: 5 V/DIV, CH2: 20 V/DIV
TIME: 40 ms/DIV
Measurement
condition • After warmed up to normal
operating temperature
• Engine at specified idle speed
1. Cylinder reference signal (CMP reference signal)
3. 720 ° crank angle
Measurement
terminal CH1: “C37-20” to “C37-58”
CH2: “C37-2” to “C37-58”
Oscilloscope
setting CH1: 5 V/DIV, CH2: 20 V/DIV
TIME: 40 ms/DIV
Measurement
condition • After warmed up to normal
operating temperature
• Engine at specified idle speed
1. Cylinder reference signal (CMP reference signal)
3. 720 ° crank angle
I6RS0C110028-01
I6RS0C110029-01
Measurement
terminal CH1: “C37-4” to “C37-58”
CH2: “C37-3” to “C37-58”
CH3: “C37-19” to “C37-58”
CH4: “C37-18” to “C37-58”
Oscilloscope
setting CH1: 20 V/DIV, CH2: 20 V/DIV
CH3: 20 V/DIV, CH4: 20 V/DIV
TIME: 40 ms/DIV
Measurement
condition Engine at cranking
1. EGR valve stepper motor coil 1 signal
2. EGR valve stepper motor coil 2 signal
3. EGR valve stepper motor coil 3 signal
4. EGR valve stepper motor coil 4 signal
5. ON signal
6. OFF signal
Measurement
terminalCH1: “C37-20” to “C37-58”
CH2: “C37-5” to “C37-58”
Oscilloscope
setting CH1: 2 V/DIV, CH2: 2 V/DIV
TIME: 40 ms/DIV
Measurement
condition • After warmed up to normal
operating temperature
• Engine at specified idle speed
1. Cylinder reference signal (CMP reference signal)
3. 720 ° crank angle
I4RS0B110053-01
I6RS0C110030-01