Suzuki SX4 Service Manual page 161

DTC Troubleshooting
NOTE
If the vehicle runs under fuel deficient condition (such as a condition in which the fuel pump is unable
to draw fuel properly), DTC of misfire may possibly be detected due to fuel pressure drop even though
there is no abnormal condition existing in the Engine and Emission System.
Therefore, if the DTC still cannot be detected with "Trouble Symptom Confirmation" executed in
accordance with "Engine and Emission Control System Check" the possible cause may be due to a
running condition under insufficient fuel supply at the time of detecting DTC of misfire.
Step
1 Was "Engine and Emission Control System Check"
performed?
2 Does fuel level meter indicate "E" level (empty)?
3 Fuel quality check
1) Check that there is fuel of good quality in the fuel tank.
Is it OK?
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?
5 Fuel injector circuit check
1) Using sound scope, check each injector operating sound
at engine cranking or idling.
Do all injectors make operating sound?
6 Fuel pressure check
1) Check fuel pressure referring to "Fuel Pressure Check".
Is check result satisfactory?
7 Fuel injector check
1) Check fuel injector(s) referring to "Fuel Injector
Inspection in Section 1G".
Is check result satisfactory?
8 Ignition timing check
1) Check ignition timing referring to "Ignition Timing
Inspection in Section 1H".
Is check result satisfactory?
9 EGR system check
1) Check EGR system referring to "EGR System Inspection
(If Equipped) in Section 1B".
Is check result satisfactory?
10 Exhaust system check
1) Check exhaust system for exhaust gas clogged.
Is it OK?
Action
Engine General Information and Diagnosis:
Yes
Go to Step 2.
Add fuel and recheck.
Go to Step 4.
Go to Step 5.
Go to Step 6.
Go to Step 7.
Go to Step 8.
Go to Step 9.
Go to Step 10.
Go to Step 11.
1A-111
No
Go to "Engine and
Emission Control
System Check".
Go to Step 3.
Clean in fuel system
circuit and change fuel.
Faulty ignition coil, wire
harness, spark plug or
other system parts.
Check coupler
connection and wire
harness of injector not
making operating sound
and injector itself. If OK,
substitute a known-
good ECM and recheck.
Repair or replace fuel
system.
Replace defective
injector.
Check related sensors.
Repair or replace EGR
system.
Repair clogged of
exhaust system.