Suzuki Grand Vitara JB416 / JB420. Manual - part 25
1A-49 Engine General Information and Diagnosis:
Engine Symptom Diagnosis
S5JB0A1104010
Perform troubleshooting referring to the followings when ECM has detected no DTC and no abnormality has been
found in “Visual Inspection” and “Engine Basic Inspection”.
Condition
Possible cause
Correction / Reference Item
Hard starting (Engine
cranks OK)
Faulty spark plug
“Spark Plug Inspection in Section 1H”
Leaky high-tension cord (for M16
engine)
“High-Tension Cord Inspection (For M16
Engine) in Section 1H”
Loose connection or disconnection of
high-tension cord(s) or lead wire(s) (for
M16 engine)
“High-Tension Cord Removal and Installation
(For M16 Engine) in Section 1H”
Faulty ignition coil
“Ignition Coil Assembly (Including ignitor)
Inspection in Section 1H”
Dirty or clogged fuel hose or pipe
Malfunctioning fuel pump
Air drawn in through intake manifold
gasket or throttle body gasket
Faulty electric throttle body assembly
“Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty accelerator pedal position (APP)
sensor assembly
“Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C”
Faulty ECT sensor or MAF sensor
“Engine Coolant Temperature (ECT) Sensor
Inspection in Section 1C” or “Mass Air Flow
(MAF) and Intake Air Temperature (IAT)
Sensor Inspection in Section 1C”
Faulty ECM
Low compression
“Compression Check: For M16A Engine with
VVT in Section 1D” or “Compression Check:
For J20 Engine in Section 1D”
Poor spark plug tightening or faulty
gasket
“Spark Plug Removal and Installation in
Section 1H”
Compression leak from valve seat
“Valves and Valve Guides Inspection: For J20
Engine in Section 1D” or “Valves and Valve
Guides Inspection: For M16A Engine with VVT
in Section 1D”.
Sticky valve stem
“Valves and Valve Guides Inspection: For J20
Engine in Section 1D” or “Valves and Valve
Guides Inspection: For M16A Engine with VVT
in Section 1D”.
Weak or damaged valve springs
“Valve Spring Inspection: For J20 Engine in
Section 1D” or “Valve Spring Inspection: For
M16A Engine with VVT in Section 1D”
Compression leak at cylinder head
gasket
“Cylinder Head Inspection: For J20 Engine in
Section 1D” or “Cylinder Head Inspection: For
M16A Engine with VVT in Section 1D”
Sticking or damaged piston ring
“Pistons, Piston Rings, Connecting Rods and
Cylinders Inspection and Cleaning: For J20
Engine in Section 1D” or “Cylinders, Pistons
and Piston Rings Inspection: For M16A Engine
with VVT in Section 1D”
Worn piston, ring or cylinder
“Pistons, Piston Rings, Connecting Rods and
Cylinders Inspection and Cleaning: For J20
Engine in Section 1D” or “Cylinders, Pistons
and Piston Rings Inspection: For M16A Engine
with VVT in Section 1D”
Malfunctioning PCV valve
“PCV Valve Inspection in Section 1B”
Camshaft position control (VVT) system
out of order (for M16 engine)
“Oil Control Valve Inspection: For M16A
Engine with VVT in Section 1D”
Faulty EGR system