Downloaded from www.Manualslib.com manuals search engine 1A-46 Engine General Information and Diagnosis:
Engine noise – Valve
noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is
used.
• Specified fuel is used.
Improper valve lash“Camshaft, Tappet and Shim Inspection in
Section 1D”
Worn valve stem and guide“Valves and Valve Guides Inspection in
Section 1D”
Weak or broken valve spring“Valve Spring Inspection in Section 1D”
Warped or bent valve“Valves and Valve Guides Inspection in
Section 1D”
Engine noise – Piston,
ring and cylinder noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is
used.
• Specified fuel is used.
Worn piston, ring and cylinder bore“Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Engine noise –
Connecting rod noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is
used.
• Specified fuel is used.
Worn piston, ring and cylinder bore“Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Worn rod bearing“Crank Pin and Connecting Rod Bearings
Inspection in Section 1D”
Worn crank pin“Crank Pin and Connecting Rod Bearings
Inspection in Section 1D”
Loose connecting rod nuts“Pistons, Piston Rings, Connecting Rods and
Cylinders Removal and Installation in Section
1D”
Low oil pressureCondition “Low oil pressure”
Engine noise –
Crankshaft noise
NOTE
Before checking
mechanical noise, make
sure that:
• Specified spark plug is
used.
• Specified fuel is used.
Low oil pressureCondition “Low oil pressure”
Worn bearing“Main Bearings Inspection in Section 1D”
Worn crankshaft journal“Crankshaft Inspection in Section 1D”
Loose bearing cap bolts“Main Bearings, Crankshaft and Cylinder Block
Removal and Installation in Section 1D”
Excessive crankshaft thrust play“Crankshaft Inspection in Section 1D” Condition Possible cause Correction / Reference Item
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-47
Engine overheatingInoperative thermostat“Thermostat Inspection in Section 1F”
Poor water pump performance“Water Pump Inspection in Section 1F”
Clogged or leaky radiator“Radiator On-Vehicle Inspection and Cleaning
in Section 1F”
Improper engine oil grade“Engine Oil and Filter Change in Section 0B”
Clogged oil filter or oil strainer“Oil Pressure Check in Section 1E”
Poor oil pump performance“Oil Pressure Check in Section 1E”
Faulty radiator cooling fan control
system“Radiator Cooling Fan Control System Check”
Dragging brakesCondition “Dragging brakes” in “Brakes
Symptom Diagnosis in Section 4A”
Slipping clutch (for M/T model)Condition “Slipping clutch” in “Clutch System
Symptom Diagnosis in Section 5C” for M/T
model
Blown cylinder head gasket“Cylinder Head Inspection in Section 1D”
Air mixed in cooling system
Poor gasoline mileageLeaks or loose connection of high-
tension cord“High-Tension Cord Removal and Installation
in Section 1H”
Faulty spark plug (improper gap, heavy
deposits and burned electrodes, etc.)“Spark Plug Inspection in Section 1H”
Malfunctioning EGR valve“EGR Valve Inspection (If Equipped) in Section
1B”
High idle speedCondition “Improper engine idling or engine
fails to idle”
Poor performance of ECT sensor, MAF
sensor“Engine Coolant Temperature (ECT) Sensor
Inspection in Section 1C”, or “Intake Air
Temperature (IAT) Sensor Inspection in
Section 1C”
Faulty electric throttle body assembly“Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly“Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C”
Faulty fuel injector(s)“Fuel Injector Circuit Check”
Faulty ECM
Low compression“Compression Check in Section 1D”
Poor valve seating“Valves and Valve Guides Inspection in
Section 1D”
Dragging brakesCondition “Dragging brakes” in “Brakes
Symptom Diagnosis in Section 4A”
Slipping clutch (for M/T model)Condition “Slipping clutch” in “Clutch System
Symptom Diagnosis in Section 5C” for M/T
model
Thermostat out of order“Thermostat Inspection in Section 1F”
Improper tire pressure“Tires Description in Section 2D”
Camshaft position control (VVT) system
out of order (for engine with VVT
system)“Oil Control Valve Inspection (For Engine with
VVT) in Section 1D”
Excessive engine oil
consumption – Oil
leakageBlown cylinder head gasket“Cylinder Head Inspection in Section 1D”
Leaky camshaft oil seals“Camshaft, Tappet and Shim Inspection in
Section 1D” Condition Possible cause Correction / Reference Item
Downloaded from www.Manualslib.com manuals search engine 1A-48 Engine General Information and Diagnosis:
Excessive engine oil
consumption – Oil
entering combustion
chamberSticky piston ring“Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Worn piston and cylinder“Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Worn piston ring groove and ring“Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Improper location of piston ring gap“Pistons, Piston Rings, Connecting Rods and
Cylinders Disassembly and Assembly in
Section 1D”
Worn or damaged valve stem seal“Valves and Valve Guides Inspection in
Section 1D”
Worn valve stem“Valves and Valve Guides Inspection in
Section 1D”
Engine hesitates –
Momentary lack of
response as accelerator
is depressed. Can occur
at all vehicle speeds.
Usually most severe when
first trying to make
vehicle move, as from a
stop sign.Spark plug faulty or plug gap out of
adjustment“Spark Plug Inspection in Section 1H”
Leaky high-tension cord“High-Tension Cord Inspection in Section 1H”
Fuel pressure out of specification“Fuel Pressure Check”
Malfunctioning EGR valve“EGR Valve Inspection (If Equipped) in Section
1B”
Poor performance of ECT sensor or
MAF sensor, “Engine Coolant Temperature (ECT) Sensor
Inspection in Section 1C” or “Intake Air
Temperature (IAT) Sensor Inspection in
Section 1C”
Faulty electric throttle body assembly“Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly“Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C”
Faulty fuel injector“Fuel Injector Circuit Check”
Faulty ECM
Engine overheatingCondition “Engine overheating”
Low compression“Compression Check in Section 1D”
Camshaft position control (VVT) system
out of order (for engine with VVT
system)“Oil Control Valve Inspection (For Engine with
VVT) in Section 1D”
Surge – Engine power
variation under steady
throttle or cruise. Feels
like vehicle speeds up
and down with no change
in accelerator pedal.Leaky or loosely connected high-tension
cord“High-Tension Cord Removal and Installation
in Section 1H”
Faulty spark plug (excess carbon
deposits, improper gap, burned
electrodes, etc.)“Spark Plug Inspection in Section 1H”
Variable fuel pressure“Fuel Pressure Check”
Kinky or damaged fuel hose and lines
Faulty fuel pump (clogged fuel filter)
Malfunctioning EGR valve“EGR Valve Inspection (If Equipped) in Section
1B”
Poor performance of MAF sensor“Intake Air Temperature (IAT) Sensor
Inspection in Section 1C”
Faulty fuel injector“Fuel Injector Circuit Check”
Faulty ECM
Faulty electric throttle body assembly“Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly“Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C” Condition Possible cause Correction / Reference Item
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-49
Excessive detonation –
Engine makes
continuously sharp
metallic knocks that
change with throttle
opening. Sounds like pop
corn popping.Faulty spark plug“Spark Plug Inspection in Section 1H”
Loose connection of high-tension cord“High-Tension Cord Removal and Installation
in Section 1H”
Engine overheatingCondition “Engine overheating”
Clogged fuel filter (faulty fuel pump) or
fuel lines“Fuel Pressure Check” or “Fuel Pump and Its
Circuit Check”
Air drawn in through intake manifold or
throttle body gasket
Malfunctioning EGR valve“EGR Valve Inspection (If Equipped) in Section
1B”
Poor performance of knock sensor, ECT
sensor or MAF sensor“DTC P0327 / P0328: Knock Sensor Circuit
Low / High”, “Engine Coolant Temperature
(ECT) Sensor Inspection in Section 1C” or
“Intake Air Temperature (IAT) Sensor
Inspection in Section 1C”
Faulty fuel injector(s)“Fuel Injector Circuit Check”
Faulty ECM
Excessive combustion chamber
deposits“Cylinders, Pistons and Piston Rings
Inspection in Section 1D” and/or “Piston Pins
and Connecting Rods Inspection in Section
1D”
Camshaft position control (VVT) system
out of order (for engine with VVT
system)“Oil Control Valve Inspection (For Engine with
VVT) in Section 1D”
Engine has no powerFaulty spark plug“Spark Plug Inspection in Section 1H”
Faulty ignition coil with ignitor“Ignition Coil Assembly (Including Ignitor)
Inspection in Section 1H”
Leaks, loose connection or
disconnection of high-tension cord“High-Tension Cord Removal and Installation
in Section 1H”
Faulty knock sensor“DTC P0327 / P0328: Knock Sensor Circuit
Low / High”
Clogged fuel hose or pipe“Fuel Pressure Check”
Malfunctioning fuel pump“Fuel Pump and Its Circuit Check”
Air drawn in through intake manifold
gasket or throttle body gasket
Engine overheatingCondition “Engine overheating”
Malfunctioning EGR valve“EGR Valve Inspection (If Equipped) in Section
1B”
Poor performance of ECT sensor or
MAF sensor“Engine Coolant Temperature (ECT) Sensor
Inspection in Section 1C” or “Intake Air
Temperature (IAT) Sensor Inspection in
Section 1C”
Faulty electric throttle body assembly“Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly“Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C”
Faulty fuel injector(s)“Fuel Injector Circuit Check”
Faulty ECM
Dragging brakesCondition “Dragging brakes” in “Brakes
Symptom Diagnosis in Section 4A”
Slipping clutch (for M/T model)Condition “Slipping clutch” in “Clutch System
Symptom Diagnosis in Section 5C” (for M/T
model)
Low compression“Compression Check in Section 1D”
Camshaft position control (VVT) system
out of order (for engine with VVT
system)“Oil Control Valve Inspection (For Engine with
VVT) in Section 1D” Condition Possible cause Correction / Reference Item
Downloaded from www.Manualslib.com manuals search engine 1A-50 Engine General Information and Diagnosis:
Improper engine idling or
engine fails to idleFaulty spark plug“Spark Plug Inspection in Section 1H”
Leaky or disconnected high-tension cord“High-Tension Cord Removal and Installation
in Section 1H”
Faulty ignition coil with ignitor“Ignition Coil Assembly (Including Ignitor)
Inspection in Section 1H”
Fuel pressure out of specification“Fuel Pressure Check”
Leaky manifold, throttle body, or cylinder
head gasket
Malfunctioning EGR valve“EGR Valve Inspection (If Equipped) in Section
1B”
Faulty evaporative emission control
system“EVAP Canister Purge Inspection in Section
1B”
Faulty EGR system“EGR System Inspection (If Equipped) in
Section 1B”
Faulty fuel injector(s)“Fuel Injector Circuit Check”
Poor performance of ECT sensor or
MAF sensor“Engine Coolant Temperature (ECT) Sensor
Inspection in Section 1C”, or “Intake Air
Temperature (IAT) Sensor Inspection in
Section 1C”
Faulty electric throttle body assembly“Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly“Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C”
Faulty ECM
Loose connection or disconnection of
vacuum hoses
Malfunctioning PCV valve“PCV Valve Inspection in Section 1B”
Engine overheatingCondition “Engine overheating”
Low compression“Compression Check in Section 1D”
Camshaft position control (VVT) system
out of order (for engine with VVT
system)“Oil Control Valve Inspection (For Engine with
VVT) in Section 1D” Condition Possible cause Correction / Reference Item
Downloaded from www.Manualslib.com manuals search engine 1A-58 Engine General Information and Diagnosis:
DTC Troubleshooting
NOTE
Before this troubleshooting is performed, read the precautions for DTC troubleshooting referring to
“Precautions for DTC Troubleshooting”.
Step Action Yes No
1Was “Engine and Emission Control System Check”
performed?Go to Step 2. Go to “Engine and
Emission Control
System Check”.
2Do you have SUZUKI scan tool?Go to Step 3. Go to Step 5.
3Camshaft position control check
1) With ignition switch turned OFF, connect SUZUKI scan
tool.
2) Start engine and warm up to normal operating
temperature.
3) Select menu to “Data List”.
4) Check that “VVT GAP” displayed on SUZUKI scan tool is
0 – 3°.
Is it OK?Go to Step 4. Check valve timing
referring to “Timing
Chain and Chain
Tensioner Removal and
Installation in Section
1D”. If OK, go to Step 5.
4Camshaft position control check
1) Drive vehicle under following conditions.
• Vehicle speed at 80 km/h (50 mile/h).
• Gear position at 5th or D range.
2) Check that “VVT GAP” displayed on SUZUKI scan tool is
0 – 5°.
Is it OK?Substitute a known-
good ECM and recheck.Go to Step 5.
5Oil control circuit visual inspection
1) Remove cylinder head cover referring to “Cylinder Head
Cover Removal and Installation in Section 1D”.
2) Check oil pressure leakage from oil control circuit.
Is it in good condition?Go to Step 6. Repair or replace.
6Oil control valve and oil gallery pipe check
1) Remove oil control valve referring to “Oil Control Valve
Removal and Installation (For Engine with VVT) in
Section 1D”.
2) Remove oil gallery pipe referring to “Timing Chain Cover
Removal and Installation in Section 1D”.
3) Check oil gallery pipe and oil control valve for clog or
sludge.
Are they in good condition?Go to Step 7. Clean oil control valve
and oil gallery pipe.
Replace oil control valve
if a problem is not
solved after cleaning oil
control valve and oil
gallery pipe.
7Oil control valve electrical circuit check
1) Check that oil control valve circuit is in good condition
referring to “DTC P0010: Camshaft Position Actuator
Circuit (for engine with VVT system)”.
Is circuit in good condition?Repair circuit. Go to Step 8.
8Oil control valve check
1) Check oil control valve referring to “Oil Control Valve
Inspection (For Engine with VVT) in Section 1D”.
Is it in good condition?Replace camshaft
timing sprocket.Replace oil control
valve.
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-111
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 Action Yes No
1Was “Engine and Emission Control System Check”
performed?Go to Step 2. Go to “Engine and
Emission Control
System Check”.
2Does fuel level meter indicate “E” level (empty)?Add fuel and recheck. Go to Step 3.
3Fuel 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.
4Ignition 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.
5Fuel injector circuit check
1) Using sound scope, check each injector operating sound
at engine cranking or idling.
Do all injectors make 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.
6Fuel pressure check
1) Check fuel pressure referring to “Fuel Pressure Check”.
Is check result satisfactory?Go to Step 7. Repair or replace fuel
system.
7Fuel injector check
1) Check fuel injector(s) referring to “Fuel Injector
Inspection in Section 1G”.
Is check result satisfactory?Go to Step 8. Replace defective
injector.
8Ignition 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.
9EGR system check
1) Check EGR system referring to “EGR System Inspection
(If Equipped) in Section 1B”.
Is check result satisfactory?Go to Step 10. Repair or replace EGR
system.
10Exhaust 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 Engine General Information and Diagnosis: 1A-117
System Description
The CMP sensor located on the transmission side of cylinder head (VVT model) or timing chain cover (non-VVT
model) consists of the signal generator (magnetic sensor) and signal rotor (intake camshaft portion (VVT model) or
exhaust camshaft timing sprocket (non-VVT model)).
The signal generator generates reference signal through slits in the slit plate which turns together with the camshaft.
Reference signal
The CMP sensor generates 6 pulses of signals each of which has a different waveform length while the camshaft
makes one full rotation. Refer to “Inspection of ECM and Its Circuits”.
Based on these signals, ECM judges which cylinder piston is in the compression stroke and the engine speed.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Crank engine for 5 sec.
4) Check DTC and pending DTC.
DTC Troubleshooting
NOTE
Before this troubleshooting is performed, read the precautions for DTC troubleshooting referring to
“Precautions for DTC Troubleshooting”.
DTC detecting condition Trouble area
• CMP sensor pulse is less than 20 pulses per crankshaft 8 revolutions
or
• CMP sensor pulse is more than 28 pulses per crankshaft 8
revolutions
or
• CMP sensor pulse is less than 20 pulses between BTDC 75° CA and
BTDC 5° CA with crankshaft 8 revolutions from engine start.
(1 driving cycle detection logic)• CMP sensor circuit open or short
• Signal rotor teeth damaged
• CMP sensor malfunction, foreign material
being attached or improper installation
•ECM
Step Action Yes No
1Was “Engine and Emission Control System Check”
performed?Go to Step 2. Go to “Engine and
Emission Control
System Check”.
2CMP sensor and connector for proper installation check
Is CMP sensor installed properly and connector connected
securely?Go to Step 3. Correct.