engine overheat SUZUKI SWIFT 2000 1.G SF310 Service User Guide

6-1-26 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
ConditionPossible CauseReferring Item
Engine has no
powerIgnition system out of order

Faulty spark plug

Faulty ignition coil with ignitor

Leaks, loose connection or disconnection of
high-tension cord
Engine overheating
Fuel system out of order

Clogged fuel hose or pipe

Malfunctioning fuel pump

Air inhaling from intake manifold gasket or
throttle body gasket
Engine and emission control system out of
order

Malfunctioning EGR valve

Maladjusted accelerator cable play

Poor performance of TP sensor, ECT sensor or
MAP sensor

Faulty fuel injector(s)

Faulty ECM (PCM)
Low compression
Others

Dragging brakes

Slipping clutch
Spark plugs in Section 6F1
Ignition coil in Section 6F1
High-tension cords in Section 6F1
Refer to “Overheating” section
Diagnostic Flow Table B-3
Diagnostic Flow Table B-2
EGR system inspection in Section
6E2
Accelerator cable play in Section
6E2
TP sensor, ECT sensor or MAP
sensor in Section 6E2
Diagnostic Flow Table B-1
Previously outlined
Trouble diagnosis in Section 5
Trouble diagnosis in Section 7C

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-27
ConditionPossible CauseReferring Item
Improper engine
idling or engine
fails to idleIgnition system out of order

Faulty spark plug

Leaky or disconnected high-tension cord

Faulty ignition coil with ignitor
Fuel system out of order

Fuel pressure out of specification

Leaky manifold, throttle body, or cylinder head
gasket
Engine and emission control system out of
order

Malfunctioning EGR valve

Faulty idle air control system

Faulty evaporative emission control system

Faulty EGR system

Faulty fuel injector(s)

Poor performance of ECT sensor, TP sensor or
MAP sensor

Faulty ECM (PCM)
Engine overheating
Low compression
Others

Loose connection or disconnection of vacuum
hoses

Malfunctioning PCV valve
Spark plugs in Section 6F
High-tension cords in Section 6F
Ignition coil in Section 6F
Diagnostic Flow Table B-3
EGR system in Section 6E2
Diagnostic Flow Table B-4
EVAP control system in Section
6E2
EGR system in Section 6E2
Diagnostic Flow Table B-1
ECT sensor, TP sensor or MAP
sensor in Section 6E2
Refer to “Overheating” section
Previously outlined
PCV system in Section 6E2

6-1-48 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
To combination
(ECT) meterTo other sensors
NOTE:
Before inspecting, be sure to check that cool-
ant temp. meter in combination meter indi-
cates normal operating temperature (Engine
is not overheating).
DTC P0115 ENGINE COOLANT TEMPERATURE (ECT) CIRCUIT
MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

Low engine coolant temperature (High voltage-High resistance)

High engine coolant temperature (Low voltage-Low resistance)
“Lg / R” circuit open or shorted to power

“G” circuit open

ECT sensor malfunction

ECM (PCM) malfunction
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select “DTC” mode on scan tool and check DTC.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-69
Ignition coil assembly
for No.1 & No.4 spark plugs
Ignition coil assembly
for No.2 & No.3 spark plugs
Ignition switch
Main relay
Main
fuseRelay box
To ignition switch
CKP sensorCMP sensorNo.1 injector
No.2 injector
No.3 injector
No.4 injector Fuse box
DTC P0300 RANDOM MISFIRE DETECTED (Misfire detected at 2 or more
cylinders)
DTC P0301 CYLINDER 1 MISFIRE DETECTED
DTC P0302 CYLINDER 2 MISFIRE DETECTED
DTC P0303 CYLINDER 3 MISFIRE DETECTED
DTC P0304 CYLINDER 4 MISFIRE DETECTED
CIRCUIT DESCRIPTION
ECM (PCM) monitors crankshaft revolution speed and engine speed via the crankshaft position sensor and cylin-
der No. via the camshaft position sensor. Then it calculates the change in the crankshaft revolution speed and from
how many times such change occurred in every 200 or 1000 engine revolutions, it detects occurrence of misfire.
When ECM (PCM) detects a misfire (misfire rate per 200 revolutions) which can cause overheat and damage to
the three way catalytic converter, it makes the malfunction indicator lamp (MIL) flash as long as misfire occurs at
that rate.
After that, however, when the misfire rate drops, MIL remains ON until it has been judged as normal 3 times under
the same driving conditions.
Also, when ECM (PCM) detects a misfire (misfire rate per 1000 revolutions) which will not cause damage to three
way catalytic converter but can cause exhaust emission to be deteriorated, it makes MIL light according to the 2
driving cycle detection logic.

Below
specified value
6-1-70 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
1. CKP sensor signal
2. No.1 fuel injector signal
3. No.3 fuel injector signal
4. Fuel injection time
Display of fuel injection signal using oscilloscope
Waveforms at specified idle speed5ms/Div
DTC DETECTING CONDITIONPOSSIBLE CAUSE

Engine under other than high revolution condition

Not on rough road

Engine speed changing rate

Manifold absolute
pressure changing rate

Throttle opening changing rate

Misfire rate per 200 or 1000 engine revolutions (how
much and how often crankshaft revolution speed
changes) is higher than specified value
Engine overheating

Vacuum leaks (air inhaling) from air intake system

Ignition system malfunction (spark plug(s), high-
tension cord(s), ignition coil assembly)

Fuel pressure out of specification

Fuel injector malfunction (clogged or leakage)

Engine compression out of specification

Valve lash (clearance) out of specification

Manifold absolute pressure sensor malfunction

Engine coolant temp. sensor malfunction

PCV valve malfunction

EVAP control system malfunction

EGR system malfunction
DTC CONFIRMATION PROCEDURE
NOTE:
Among different types of random misfire, if misfire occurs at cylinders 1 and 4 or cylinders 3 and 2 simulta-
neously, it may not possible to reconfirm DTC by using the following DTC confirmation procedure. When
diagnosing the trouble of DTC P0300 (Random misfire detected) of the engine which is apparently misfir-
ing, even if DTC P0300 cannot be reconfirmed by using the following DTC confirmation procedure, pro-
ceed to the following Diag. Flow Table.
WARNING:

When performing a road test, select a place where there is no traffic or possibility of a traffic accident
and be very careful during testing to avoid occurrence of an accident.

Road test should be carried out with 2 persons, a driver and a tester.
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Check vehicle and environmental condition for:
–Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Intake air temp.: between –10C and 80C (14F and 176F)
–Engine coolant temp.: –10C, 14F or higher
4) Start engine and keep it at idle for 2 min. or more.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
6) If DTC is not detected at idle, consult usual driving based on information obtained in “Customer complaint analy-
sis” and “Freeze frame data check”.
Reference

6B-4 ENGINE COOLING
COOLANT (WATER) TEMP. GAUGE
The coolant temp. gauge is included in engine coolant temp. (ECT)
sensor (1). This gauge activates a temp. meter in the instrument
cluster.
DIAGNOSIS
ConditionPossible CauseCorrection
Engine overheatsLoose or broken water pump belt
Not enough coolant
Faulty thermostat
Faulty water pump
Dirty or bent radiator fins
Coolant leakage on cooling system
Defective cooling fan motor
Plugged radiator
Faulty radiator cap
Maladjusted ignition timing
Dragging brakes
Slipping clutchAdjust or replace.
Check coolant level and add as
necessary.
Replace.
Replace.
Clean or remedy.
Repair.
Check and replace as
necessary.
Check and replace radiator as
necessary.
Replace.
Adjust.
Adjust brake.
Adjust or replace.

2. Thermostat case
2. Thermometer
3. Heater
Upside
6B-8 ENGINE COOLING
4) Remove thermostat (1).
INSPECTION
1) Make sure that air bleed valve (1) of thermostat is clean.
Should this valve be clogged, engine would tend to overheat.
2) Check to make sure that valve seat is free from foreign matters
which would prevent valve from seating tight.
3) Check thermostatic movement of wax pellet as follows:
Immerse thermostat (1) in water, and heat water gradually.
Check that valve starts to open at specific temperature.
If valve starts to open at a temperature substantially below or
above specific temperature, thermostat unit should be re-
placed with a new one. Such a unit, if reused, will bring about
overcooling or overheating tendency.
INSTALLATION
1) When positioning thermostat on thermostat case, be sure to
position it so that air bleed valve comes uppermost and into the
recession of thermostat case.
2) Install thermostat cap to thermostat case. When installing cap,
align arrow marks on cap and case.
3) Fill cooling system.
4) Connect negative cable.
5) After installation, check each part for leakage.