Suzuki Liana RH413, Service Manual

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Engine General Information and Diagnosis: 1A-72
DTC Detecting Condition and Possible Cause
DTC Confirmation Procedure
NOTE
Among different types of random misfire, if
misfire occurs at cylinders 1 and 4 or
cylinders 3 and 2 simultaneously, it may not
possible to reconfirm DTC by using the
following “DTC Confirmation Procedure”.
When diagnosing the trouble of DTC P0300
(Random misfire detected) of the engine
which is apparently misfiring, even if DTC
P0300 cannot be reconfirmed by using the
following “DTC Confirmation Procedure”,
proceed to the following diag. flow.
WARNING
!
• When performing a road test, select a
place where there is no traffic or
possibility of a traffic accident and very
careful during testing to avoid occurrence
of an accident.
• Road test should be carried out with 2
persons, a driver and tester, on a level
road.
NOTE
Check to make sure that the following
conditions are satisfied when using this DTC
confirmation procedure.
• Altitude (barometric pressure): 2400 m,
8000 ft or less (560 mmHg, 75 kPa or more)
• Ambient temp.: –10
°
C, 14
°
F or higher
• Intake air temp.: 70
°
C, 158
°
F or lower
• Engine coolant temp.: –10 – 110
°
C, 14 –
230
°
F
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Start engine and keep it at idle for 2 min. or more.
4) Check DTC and pending DTC.
5) If DTC is not detected at idle, consult usual driving
based on information obtained in “Customer
Complaint Analysis” and “Freeze Frame Data
Check”.
DTC Troubleshooting
CAUTION
!
For iridium spark plugs, do not adjust air gap or clean.
DTC detecting condition Possible cause
• Engine under other than high revolution condition
• Not on rough road
• Engine speed changing rate (below specified value)
• Manifold absolute pressure changing rate (below specified
value)
• Throttle opening changing rate (below specified value)
• Misfire rate per 200 or 1000 engine revolutions (how much and
how often crankshaft revolution speed changes) is higher than
specified value
• Engine overheating
• Vacuum leaks (air inhaling) from air intake
system
• Ignition system malfunction (spark plug(s), high-
tension cord(s), ignition coil assembly)
• Fuel pressure out of specification
• Fuel injector malfunction (clogged or leakage)
• Engine compression out of specification
• Valve lash (clearance) out of specification
• Manifold absolute pressure sensor malfunction
• Engine coolant temp. sensor malfunction
• PCV valve malfunction
• EVAP control system malfunction
• EGR system malfunction
Step Action Yes No
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 other than fuel system (DTC P0171 / P0172)
and misfire (DTC P0300 – P0304)? Go to applicable DTC
diag. flow. Go to Step 3.