Engine Diagnosis Table - Suzuki 2000 Grand Vitara SQ625 Service Manual

ENGINE DIAGNOSIS TABLE

Perform troubleshooting referring to following table when ECM (PCM) has detected no DTC and no abnormality
has been found in visual inspection and engine basic inspection previously.
Condition
Hard starting
(Engine cranks OK.)
Engine has no power
Possible Cause
Engine and emission control system
out of order.
D Faulty idle air control system
D Faulty ECT sensor or MAF sensor
D Faulty ECM (PCM)
Low compression.
D Faulty hydraulic valve lash adjuster
D Compression leak from valve seat
D Sticky valve stem
D Weak or damaged valve springs
D Compression leak at cylinder head
gasket
D Sticking or damaged piston ring
D Worn piston, ring or cylinder
Others
D Malfunctioning PCV valve
Engine overheating.
Ignition system out of order.
D Defective spark plug
D Faulty ignition coil with ignitor
Fuel system out of order.
D Fuel pressure out of specification
– Dirty fuel filter
– Dirty or clogged fuel hose or pipe
– Malfunctioning fuel pressure regulator
– Malfunctioning fuel pump
Engine and emission control system
out of order.
D Maladjusted TP sensor installation
angle
D Faulty EGR system
D Faulty injector
D Faulty TP sensor, ECT sensor or
MAF sensor
D Faulty ECM (PCM)
Low compression.
Others
D Dragging brakes
D Slipping clutch
ENGINE (H25 ENGINE) 6-1-33
Reference Item
DTC P0505 Diag. Flow Table in this
section.
ECT sensor or MAF sensor in Engine
and Emission Control System
section.
Inspection of ECM (PCM) and its
circuit in this section.
Compression check in Engine
Mechanical section.
Valve lash adjuster in Engine
Mechanical section.
Valves inspection in Engine
Mechanical section.
Valves inspection in Engine
Mechanical section.
Valves spring inspection in Engine
Mechanical section.
Cylinder head inspection in Engine
Mechanical section.
Piston ring inspection in Engine
Mechanical section.
Cylinders, pistons and piston rings
inspection in Engine Mechanical
section.
PCV system inspection in Engine and
Emission Control System section.
Refer to "Overheating" section.
Spark plugs in Ignition System
section.
Ignition coil in Ignition System
section.
Diag. Flow Table B-3 in this section.
TP sensor in Engine and Emission
Control System section.
DTC P0400 Diag. Flow Table in this
section.
Fuel injector in Engine and Emission
Control System section.
TP sensor, ECT sensor or MAF
sensor in Engine and Emission
Control System section.
Inspection of ECM (PCM) and its
circuit in this section.
Previously outlined.
Diagnosis in BRAKES section.
Diagnosis in Clutch section.