Engine Symptom Diagnosis

Perform troubleshooting referring to the following table when ECM has detected no DTC and no abnormality has been found VISUAL INSPECTION in and ENGINE BASIC CHECK .

DIAGNOSIS PROCEDURE

Possible Cause	Action
Faulty ECT sensor or MAF sensor	Refer to ENGINE COOLANT TEMPERATURE (ECT) Sensor Inspection or Mass Air Flow (MAF) and Intake Air Temperature (IAT) Sensor On-Vehicle Inspection .
Faulty ECM	Refer to INSPECTION OF ECM AND ITS CIRCUITS .
Low compression	Refer to COMPRESSION CHECK .
Compression leak from valve seat	Refer to VALVES AND VALVE GUIDES INSPECTION .
Sticky valve stem	Refer to VALVES AND VALVE GUIDES INSPECTION .
Weak or damaged valve springs	Refer to VALVE SPRINGS INSPECTION .
Compression leak at cylinder head gasket	Refer to CYLINDER HEAD INSPECTION .
Sticking or damaged piston ring	Refer to CYLINDERS, PISTONS AND PISTON RINGS INSPECTION .
Worn piston, ring or cylinder	Refer to PISTON PINS AND CONNECTING RODS INSPECTION .
Malfunctioning PCV valve	Refer to PCV VALVE INSPECTION .
Faulty spark plug	Refer to SPARK PLUG INSPECTION .
Faulty ignition coil with ignitor	Refer to IGNITION COIL ASSEMBLY (IGNITER AND IGNITION COIL) INSPECTION .
Dirty or clogged fuel hose or pipe	Refer to FUEL PRESSURE CHECK .
Malfunctioning fuel pump	Refer to FUEL PRESSURE CHECK .
Air drawn in through intake manifold gasket or throttle body gasket	Check air intake system .
Faulty electric throttle body assembly	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION .
Faulty accelerator pedal position (APP) sensor assembly	Refer to ACCELERATOR PEDAL POSITION (APP) SENSOR ASSEMBLY INSPECTION .
Faulty EGR system	Refer to EGR SYSTEM INSPECTION (USING SUZUKI SCAN TOOL) .
Engine overheating	Refer to condition of Overheating in ENGINE COOLING SYMPTOM DIAGNOSIS "
Defective spark plug.	Refer to SPARK PLUG INSPECTION .
Faulty ignition coil with ignitor	Refer to IGNITION COIL ASSEMBLY (IGNITER AND IGNITION COIL) INSPECTION .
Fuel pressure out of specification Dirty fuel filter Dirty or clogged fuel hose or pipe Faulty fuel pressure regulator Faulty fuel pump	Refer to FUEL PRESSURE CHECK .
Faulty EGR system	Refer to PCV VALVE INSPECTION .
Faulty injector	Refer to FUEL INJECTOR INSPECTION .
Faulty ECT sensor or MAF sensor	Refer to ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION or MASS AIR FLOW (MAF) AND INTAKE AIR TEMPERATURE (IAT) SENSOR ON-VEHICLE INSPECTION .
Faulty ECM	Refer to INSPECTION OF ECM AND ITS CIRCUITS .
Low compression	Refer to COMPRESSION CHECK .
Dragging brakes	Refer to condition: "Dragging Brakes" in BRAKES SYMPTOM DIAGNOSIS .
Slipping clutch	Refer to condition: "Slipping clutch" in DIAGNOSTIC INFORMATION AND PROCEDURE .
Faulty knock sensor	Refer to DTC P0327/P0328: KNOCK SENSOR CIRCUIT LOW / HIGH .
Air drawn in through intake manifold or throttle body gasket	Check air intake system .
Faulty electric throttle body assembly	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION .
Faulty accelerator pedal position (APP) sensor assembly	Refer to ACCELERATOR PEDAL POSITION (APP) SENSOR ASSEMBLY INSPECTION .
Faulty IMT vacuum solenoid valve	Refer to IMT VACUUM TANK ASSEMBLY INSPECTION .
Faulty spark plug	Refer to SPARK PLUG INSPECTION .
Faulty ignition coil with ignitor	Refer to IGNITION COIL ASSEMBLY (IGNITER AND IGNITION COIL) INSPECTION .
Fuel pressure out of specification	Refer to FUEL PRESSURE CHECK .
Engine overheating	Refer to condition of "Overheating" in ENGINE COOLING SYMPTOM DIAGNOSIS .
Faulty Idle air flow malfunction	Refer to DTC P0506 / P0507: IDLE AIR CONTROL SYSTEM RPM LOWER THAN EXPECTED / HIGHER THAN EXPECTED .
Faulty evaporative emission control system	Refer to EVAP CANISTER PURGE VALVE AND ITS CIRCUIT .
Faulty EGR system	Refer to PCV VALVE INSPECTION .
Faulty injector	Refer to FUEL INJECTOR INSPECTION .
Faulty ECT sensor or MAF sensor	Refer to ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION or MASS AIR FLOW (MAF) AND INTAKE AIR TEMPERATURE (IAT) SENSOR ON-VEHICLE INSPECTION .
Faulty ECM	Refer to INSPECTION OF ECM AND ITS CIRCUITS .
Low compression	Refer to COMPRESSION CHECK .
Malfunctioning PCV valve	Refer to PCV VALVE INSPECTION .
Leaky intake manifold, throttle body or cylinder head gasket	Check air intake system .
Faulty electric throttle body assembly	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION .
Faulty accelerator pedal position (APP) sensor assembly	Refer to ACCELERATOR PEDAL POSITION (APP) SENSOR ASSEMBLY INSPECTION.
Loose connection or disconnection of vacuum hoses	Check connection or disconnection of vacuum hoses
Faulty electric load parts (headlight, blower motor and/or rear defogger)	Refer to Electric Load Signal Circuit Check .
Spark plug faulty or plug gap as out of adjustment	Refer to SPARK PLUG INSPECTION .
Fuel pressure out of specification Dirty fuel filter Dirty or clogged fuel hose or pipe Faulty fuel pressure regulator Faulty fuel pump	Refer to FUEL PRESSURE CHECK .
Engine overheating	Refer to condition of "Overheating" in ENGINE COOLING SYMPTOM DIAGNOSIS .
Faulty EGR system	Refer to PCV VALVE INSPECTION .
Faulty injector	Refer to FUEL INJECTOR INSPECTION .
Faulty ECT sensor or MAF sensor	Refer to ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION or MASS AIR FLOW (MAF) AND INTAKE AIR TEMPERATURE (IAT) SENSOR ON-VEHICLE INSPECTION .
Faulty ECM	Refer to INSPECTION OF ECM AND ITS CIRCUITS .
Low compression	Refer to COMPRESSION CHECK .
Faulty electric throttle body assembly	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION .
Faulty accelerator pedal position (APP) sensor assembly	Refer to ACCELERATOR PEDAL POSITION (APP) SENSOR ASSEMBLY INSPECTION
Defective spark plug (excess carbon deposits, improper gap, and burned electrodes, etc.)	Refer to SPARK PLUG INSPECTION .
Variable fuel pressure Dirty fuel filter Dirty or clogged fuel hose or pipe Faulty fuel pressure regulator Faulty fuel pump	Refer to FUEL PRESSURE CHECK .
Faulty EGR system	Refer to PCV VALVE INSPECTION .
Faulty MAF sensor	Refer to MASS AIR FLOW (MAF) AND INTAKE AIR TEMPERATURE (IAT) SENSOR ON-VEHICLE INSPECTION .
Faulty injector	Refer to FUEL INJECTOR INSPECTION .
Faulty ECM	Refer to INSPECTION OF ECM AND ITS CIRCUITS .
Faulty electric throttle body assembly	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION .
Faulty accelerator pedal position (APP) sensor assembly	Refer to ACCELERATOR PEDAL POSITION (APP) SENSOR ASSEMBLY INSPECTION
Engine overheating	Refer to condition of "Overheating" in ENGINE COOLING SYMPTOM DIAGNOSIS .
Faulty spark plug	Refer to SPARK PLUG INSPECTION .
Improper ignition timing	Refer to IGNITION TIMING INSPECTION .
Clogged fuel filter and fuel lines	Refer to FUEL PRESSURE CHECK .
Faulty EGR system	Refer to PCV VALVE INSPECTION .
Faulty knock sensor, ECT sensor or MAF sensor	Refer to DTC P0327 / P0328: KNOCK SENSOR CIRCUIT LOW / HIGH, ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION OR MASS AIR FLOW (MAF) AND INTAKE AIR TEMPERATURE (IAT) SENSOR ON-VEHICLE INSPECTION .
Faulty injector	Refer to FUEL INJECTOR INSPECTION .
Faulty ECM	Refer to INSPECTION OF ECM AND ITS CIRCUITS .
Excessive combustion chamber deposits	Refer to CYLINDER HEAD INSPECTION CYLINDERS, PISTONS AND PISTON RINGS INSPECTION .
Fuel pressure out of specification Dirty fuel filter Dirty or clogged fuel hose or pipe Faulty fuel pressure regulator Faulty fuel pump	Refer to FUEL PRESSURE CHECK .
Air drawn in through intake manifold or throttle body gasket	Check air intake system .
Inoperative thermostat	Refer to THERMOSTAT INSPECTION .
Poor water pump performance	Refer to WATER PUMP INSPECTION .
Clogged or leaky radiator	Refer to RADIATOR ON-VEHICLE INSPECTION AND CLEANING .
Improper engine oil grade	Refer to ENGINE OIL AND FILTER CHANGE .
Clogged oil filter or oil strainer	Refer to ENGINE OIL AND FILTER CHANGE or OIL PAN AND OIL PUMP STRAINER CLEANING .
Poor oil pump performance	Refer to OIL PUMP INSPECTION .
Dragging brakes	Refer to condition: "Dragging brakes" in BRAKES SYMPTOM DIAGNOSIS .
Slipping clutch	Refer to condition: "Slipping clutch" in DIAGNOSTIC INFORMATION AND PROCEDURE .
Blown cylinder head gasket	Refer to CYLINDER HEAD INSPECTION .
Faulty radiator cooling fan control system	Refer to DTC P0480 / P0481 / P0482: FAN 1 / FAN 2 / FAN 3 CONTROL CIRCUIT .
Air mixed in cooling system	Release air from cooling system .
Faulty spark plug (improper gap, heavy deposits, and burned electrodes, etc.)	Refer to SPARK PLUG INSPECTION .
Fuel pressure out of specification	Refer to FUEL PRESSURE CHECK .
Faulty ECT sensor or MAF sensor	Refer to ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION or MASS AIR FLOW (MAF) AND INTAKE AIR TEMPERATURE (IAT) SENSOR ON-VEHICLE INSPECTION .
Faulty EGR system	Refer to PCV VALVE INSPECTION .
Faulty injector	Refer to FUEL INJECTOR INSPECTION .
Faulty ECM	Refer to INSPECTION OF ECM AND ITS CIRCUITS .
Low compression	Refer to COMPRESSION CHECK .
Poor valve seating	Refer to VALVES AND VALVE GUIDES INSPECTION .
Dragging brakes Refer to condition: "Dragging brakes" in	BRAKES SYMPTOM DIAGNOSIS .
Slipping clutch	Refer to condition: "Slipping clutch" in DIAGNOSTIC INFORMATION AND PROCEDURE .
Thermostat out of order	Refer to THERMOSTAT INSPECTION .
Improper tire pressure	Adjust tire pressure .
High idle speed	Refer to "Improper engine idling or engine fails to idle" under ENGINE SYMPTOM DIAGNOSIS .
Faulty electric throttle body assembly	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION .
Faulty accelerator pedal position (APP) sensor assembly	Refer to ACCELERATOR PEDAL POSITION (APP) SENSOR ASSEMBLY INSPECTION
Sticky piston ring	Refer to CYLINDERS, PISTONS AND PISTON RINGS INSPECTION .
Worn piston and cylinder	Refer to CYLINDERS, PISTONS AND PISTON RINGS INSPECTION .
Worn piston ring groove and ring	Refer to CYLINDERS, PISTONS AND PISTON RINGS INSPECTION .
Improper location of piston ring gap	Refer to PISTONS, PISTON RINGS, CONNECTING RODS AND CYLINDERS REMOVAL AND INSTALLATION .
Worn or damaged valve stem seal	Replace .
Worn valve stem	Refer to VALVES AND VALVE GUIDES INSPECTION .
Improper oil viscosity	Refer to ENGINE OIL AND FILTER CHANGE .
Malfunctioning oil pressure switch	Refer to OIL PRESSURE SWITCH INSPECTION .
Clogged oil strainer	Refer to OIL PAN AND OIL PUMP STRAINER CLEANING .
Functional deterioration of oil pump	Refer to OIL PUMP INSPECTION .
Worn oil pump relief valve	Refer to OIL PUMP INSPECTION .
Excessive clearance in various sliding parts	Refer to OIL PUMP INSPECTION .
Improper valve lash	Refer to VALVE LASH (CLEARANCE) INSPECTION .
Worn valve stem and guide	Refer to VALVES AND VALVE GUIDES INSPECTION .
Weak or broken valve spring	Refer to VALVE SPRINGS INSPECTION .
Warped or bent valve	Refer to VALVES AND VALVE GUIDES INSPECTION .
Loose camshaft housing bolts	Refer to CAMSHAFTS, TAPPETS AND SHIMS REMOVAL AND INSTALLATION .
Worn piston, ring and cylinder bore	Refer to CYLINDERS, PISTONS AND PISTON RINGS INSPECTION .
Worn crank pin bearing	Refer to CRANK PINS AND CONNECTING ROD BEARINGS INSPECTION .
Worn crank pin or connecting rod bearings	Refer to CRANK PINS AND CONNECTING ROD BEARINGS INSPECTION .
Loose connecting rod nuts	Refer to PISTONS, PISTON RINGS, CONNECTING RODS AND CYLINDERS REMOVAL AND INSTALLATION .
Low oil pressure	Refer to condition "Low oil pressure" previously described .
Worn crankshaft journal bearing	Refer to MAIN BEARINGS INSPECTION .
Worn crankshaft journal	Refer to CRANKSHAFT INSPECTION .
Loose lower crankcase (bearing cap) bolts	Refer to MAIN BEARINGS, CRANKSHAFT AND CYLINDER BLOCK REMOVAL AND INSTALLATION .
Excessive crankshaft thrust play	Refer to CRANKSHAFT INSPECTION .
Engine not at normal operating temperature	Refer to AIR CLEANER FILTER INSPECTION AND CLEANING .
Clogged air cleaner	Refer to AIR CLEANER FILTER INSPECTION AND CLEANING .
Vacuum leaks	Refer to ENGINE VACUUM CHECK .
Faulty spark plug	Refer to SPARK PLUG INSPECTION .
Faulty ignition coil with ignitor	Refer to IGNITION COIL ASSEMBLY (IGNITER AND IGNITION COIL) INSPECTION .
Low compression	Refer to COMPRESSION CHECK .
Lead contamination of three way catalytic converter	Check for absence of filler neck restrictor .
Faulty evaporative emission control system	Refer to EVAP CANISTER PURGE VALVE AND ITS CIRCUIT .
Fuel pressure out of specification Dirty fuel filter Dirty or clogged fuel hose or pipe Faulty fuel pressure regulator Faulty fuel pump	Refer to FUEL PRESSURE CHECK .
Closed loop system (A/F feedback compensation) fails (faulty TP sensor, poor performance of ECT sensor or MAF sensor)	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION , ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .
Faulty electric throttle body assembly	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION .
Faulty accelerator pedal position (APP) sensor assembly	Refer to ACCELERATOR PEDAL POSITION (APP) SENSOR ASSEMBLY INSPECTION .
Faulty injector	Refer to FUEL INJECTOR CIRCUIT CHECK
Faulty ECM	Refer to INSPECTION OF ECM AND ITS CIRCUITS .
Improper ignition timing	Refer to IGNITION TIMING INSPECTION .
Lead contamination of catalytic Sconverter	Check for absence of filler neck restrictor .
Faulty EGR system	Refer to EGR SYSTEM INSPECTION (USING SUZUKI SCAN TOOL) .
Fuel pressure out of specification Dirty fuel filter Dirty or clogged fuel hose or pipe Faulty fuel pressure regulator Faulty fuel pump	Refer to FUEL PRESSURE CHECK .
Closed loop system (A/F feedback compensation) fails (faulty TP sensor, poor performance of ECT sensor or MAF sensor)	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .
Faulty electric throttle body assembly	Refer to ELECTRIC THROTTLE BODY ASSEMBLY ON-VEHICLE INSPECTION .
Faulty accelerator pedal position (APP) sensor assembly	Refer to ACCELERATOR PEDAL POSITION (APP) SENSOR ASSEMBLY INSPECTION
Faulty injector	Refer to FUEL INJECTOR CIRCUIT CHECK
Faulty ECM	Refer to INSPECTION OF ECM AND ITS CIRCUITS .