LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2006 >> Grand Vitara Base, AWD, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> Testing & Diagnosis >> Engine General Information And Diagnosis >> Diagnostic Information And Procedures >> Engine Symptom Diagnosis
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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

Condition Possible Cause Action
Hard starting (Engine cranks OK)  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 has no power  Engine overheating Refer to ENGINE COOLING SYMPTOM DIAGNOSIS .
Defective spark plug. Refer 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 CLUTCH (HYDRAULIC TYPE) SYMPTOM DIAGNOSIS .
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 .
Improper engine idling or engine fails to idle  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 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 or 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 .
Engine hesitates (Momentary lack of response as the accelerator is depressed. Can occur at all vehicle speeds. Usually most severe when first trying to make the vehicle move, as from a stop sign).  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 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 .
Surges (Engine power variation under steady throttle or cruise. Feels like the vehicle speeds up and down with no change in the accelerator pedal).  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 .
Excessive detonation (The engine makes sharp metallic knocks that change with throttle opening. Sounds like pop corn popping).  Engine overheating Refer to 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 and 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.
Overheating  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 CLUTCH (HYDRAULIC TYPE) SYMPTOM DIAGNOSIS .
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.
Poor gasoline mileage  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 CLUTCH (HYDRAULIC TYPE) SYMPTOM DIAGNOSIS .
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 .
Excessive engine oil consumption  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 DISASSEMBLY AND REASSEMBLY .
Worn or damaged valve stem seal Replace  .
Worn valve stem Refer to VALVES AND VALVE GUIDES INSPECTION .
Low oil pressure  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
Engine noise 
NOTE: Before checking the mechanical noise, make sure that:
  • Ignition timing.
  • Specified spark plug is used.
  • Specified fuel is used.
 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  OIL PRESSURE CHECK  .
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 .
Excessive hydrocarbon (HC) emission or carbon monoxide (CO)  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 or MASS AIR FLOW (MAF) AND INTAKE AIR TEMPERATURE (IAT) SENSOR ON-VEHICLE 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 .
Excessive nitrogen oxides (NOx) emission  Improper ignition timing Refer to IGNITION TIMING INSPECTION .
Lead contamination of catalytic converter 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 or MASS AIR FLOW (MAF) AND INTAKE AIR TEMPERATURE (IAT) SENSOR ON-VEHICLE 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 .
scientia non olet · About LEMON Manuals