Exhaust SUZUKI SWIFT 2000 1.G SF310 Service Owner's Manual

6-76 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Oscilloscope Waveforms
Engine running at
Closed loop conditionFuel
CutIdle after fuel cut 0.5 V / Div
2 sec. / Div Heated
oxygen
sensor-1
Warm up three way
catalytic converter (if equipped)
Three way catalytic converterTo other sensor
To other
sensors
Heated oxygen sensor-2
G
DTC P0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD
CIRCUIT DESCRIPTION
ECM (PCM) monitors oxygen concentration in the exhaust gas which has passed the three way catalytic converter
by HO2S-2.
When the catalyst is functioning properly, the variation cycle of HO2S-2 output voltage (oxygen concentration) is
slower than that of HO2S-1 output voltage because of the amount of oxygen in the exhaust gas which has been
stored in the catalyst.
Reference
DTC DETECTING CONDITIONPOSSIBLE CAUSE

While vehicle running at constant speed under other
than high load.

Time from rich or lean switching command is output
till HO2S-2 output voltage crosses 0.45 V is less than
specified value.
2 driving cycle detection logic, monitoring once / 1
driving.
Exhaust gas leak

Three way catalytic converter malfunction

Fuel system malfunction

HO2S-2 malfunction

HO2S-1 malfunction

HOSE CONNECTION
Clamp securely at a position 3 to
7mm (0.12–0.27 in.) from hose end. With short pipe, fit hose as far as it reaches pipe joint as
shown.
Hose
Pipe
ClampClamps securely at a position
3 to 7 mm (0.12–0.27 in.)
from hose end.
With following type pipe, fit hose as far as its peripheral
projection as shown.
Clamp securely at a position
3 to 7 mm (0.12–0.27 in.)
from hose end.
With bent pipe, fit hose as its bent part as shown or till pipe
is about 20 to 30 mm (0.79–1.18 in.) into the hose.
Clamp securely at a
position 3 to 7 mm
(0.12–0.27 in.) from hose
end.
With straight pipe, fit hose till pipe is, about 20 to 30 mm
(0.79–1.18 in.) into the hose.
Hose
20 to 30 mm
(0.79–1.18 in.)
Clamp
6-1-4 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
PRECAUTION ON FUEL SYSTEM SERVICE

Work must be done with no smoking, in a well-ventilated area and
away from any open flames.

As fuel feed line (between fuel pump and fuel delivery pipe) is still
under high fuel pressure even after engine was stopped, loosen-
ing or disconnecting fuel feed line directly may cause dangerous
spout of fuel to occur where loosened or disconnected.
Before loosening or disconnecting fuel feed line, make sure to re-
lease fuel pressure according to “FUEL PRESSURE RELIEF
PROCEDURE”. A small amount of fuel may be released after the
fuel line is disconnected. In order to reduce the chance of person-
al injury, cover the fitting to be disconnected with a shop cloth. Put
that cloth in an approved container when disconnection is com-
pleted.

Never run engine with fuel pump relay disconnected when engine
and exhaust system are hot.

Fuel or fuel vapor hose connection varies with each type of pipe.
When reconnecting fuel or fuel vapor hose, be sure to connect
and clamp each hose correctly referring to left figure Hose Con-
nection.
After connecting, make sure that it has no twist or kink.

When installing injector or fuel delivery pipe, lubricate its O-ring
with spindle oil or gasoline.

When connecting fuel pipe flare nut, first tighten flare nut by hand
and then tighten it to specified torque.

6-1-6 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
ENGINE DIAGNOSIS
GENERAL DESCRIPTION
This vehicle is equipped with an engine and emission control system which are under control of ECM (PCM).
The engine and emission control system in this vehicle are controlled by ECM (PCM). ECM (PCM) has an On-
Board Diagnostic system which detects a malfunction in this system and abnormality of those parts that influence
the engine exhaust emission. When diagnosing engine troubles, be sure to have full understanding of the outline
of “On-Board Diagnostic System” and each item in “Precaution in Diagnosing Trouble” and execute diagnosis ac-
cording to “ENGINE DIAGNOSTIC FLOW TABLE”.
There is a close relationship between the engine mechanical, engine cooling system, ignition system, exhaust sys-
tem, etc. and the engine and emission control system in their structure and operation. In case of an engine trouble,
even when the malfunction indicator lamp (MIL) doesn’t turn ON, it should be diagnosed according to this flow table.
ON-BOARD DIAGNOSTIC SYSTEM
ECM (PCM) in this vehicle has following functions.

When the ignition switch is turned ON with the engine at a stop,
malfunction indicator lamp (MIL) (1) turns ON to check the bulb
of the malfunction indicator lamp (1).

When ECM (PCM) detects a malfunction which gives an adverse
effect to vehicle emission while the engine is running, it makes the
malfunction indicator lamp (1) in the meter cluster of the instru-
ment panel turn ON or flash (flashing only when detecting a mis-
fire which can cause damage to the catalyst) and stores the mal-
function area in its memory.
(If it detects that continuously 3 driving cycles are normal after de-
tecting a malfunction, however, it makes MIL (1) turn OFF al-
though DTC stored in its memory will remain.)

As a condition for detecting a malfunction in some areas in the
system being monitored by ECM (PCM) and turning ON the mal-
function indicator lamp (1) due to that malfunction, 2 driving cycle
detection logic is adopted to prevent erroneous detection.

When a malfunction is detected, engine and driving conditions
then are stored in ECM (PCM) memory as freeze frame data. (For
the details, refer to description on Freeze frame data.)

It is possible to communicate by using not only SUZUKI scan tool
(Tech-1) (2) but also generic scan tool. (Diagnostic information
can be accessed by using a scan tool.)

6-1-16 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
DTC
NO.DETECTING ITEMDETECTING CONDITION
(DTC will set when detecting:)MIL
P0335Crankshaft position sensor
circuit malfunctionNo signal for 2 sec. During engine cranking1 driving
cycle
P0340Camshaft position sensor circuit
malfunctionNo signal during engine running1 driving
cycle
P0400Exhaust gas recirculation
flow malfunction detectedExcessive or insufficient EGR flow2 driving
cycles
P0420Catalyst system efficiency below
threshold
Output waveforms of HO2S-1 and HO2S-2 are
similar.
(Time from output voltage change of HO2S-1 to that
of HO2S-2 is shorter than specification.)
2 driving
cycles
P0443Purge control valve circuit
malfunctionPurge control valve circuit is open or shorted to
ground2 driving
cycles
P0480Radiator fan control circuit
malfunctionRadiator cooling fan relay terminal voltage is low
when cooling temp. is lower than specification2 driving
cycles
P0500Vehicle speed sensor
malfunctionNo signal while running in “D” range or during fuel cut
at decelerating2 driving
cycles
P0505Idle control system malfunctionNo closed signal to IAC valve is detected2 driving
cycles
P0601Internal control module memory
check sum errorData write error (or check sum error) when written
into ECM (PCM)1 driving
cycle
P1450Barometric pressure sensor
circuit malfunctionBarometric pressure is lower or higher than
specification. (or sensor malfunction)1 driving
cycle
P1451Barometric pressure sensor
performance problem
Difference between manifold absolute pressure
(MAP sensor value) and barometric pressure
(barometric pressure sensor value) is larger than
specification during cranking.
2 driving
cycles
P1500Starter signal circuit malfunctionStarter signal is not inputted from engine cranking till
its start and after or it is always inputted2 driving
cycles
P1510ECM (PCM) backup power
source malfunctionNo backup power after starting engine1 driving
cycle

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-19
Operation
VISUAL INSPECTION
Visually check following parts and systems.
INSPECTION ITEM
REFERRING SECTION

Engine oil ––––– level, leakage

Engine coolant ––––– level, leakage

Fuel ––––– level, leakage

A / T fluid ––––– level, leakage

Air cleaner element ––––– dirt, clogging

Battery ––––– fluid level, corrosion of terminal

Water pump belt ––––– tension, damage

Throttle cable ––––– play, installation

Vacuum hoses of air intake system ––––– disconnection,
looseness, deterioration, bend

Connectors of electric wire harness ––––– disconnection, friction

Fuses ––––– burning

Parts ––––– installation, bolt ––––– looseness

Parts ––––– deformation

Other parts that can be checked visually
Also check following items at engine start, if possible

Malfunction indicator lamp

Charge warning lamp

Engine oil pressure warning lamp

Engine coolant temp. meter

Fuel level meter

Tachometer, if equipped

Abnormal air being inhaled from air intake system

Exhaust system ––––– leakage of exhaust gas, noise

Other parts that can be checked visuallySection 0B
Section 0B
Section 0B
Section 0B
Section 0B
Section 0B
Section 6E2
Section 8
Section 6
Section 6H
Section 8 (Section 6 for pressure check)
Section 8
Section 8

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-31
SCAN TOOL DATA DEFINITIONS
FUEL SYSTEM (FUEL SYSTEM STATUS)
Air / fuel ratio feedback loop status displayed as either
open or closed loop. Open indicates that ECM (PCM)
ignores feedback from the exhaust oxygen sensor.
Closed indicates final injection duration is corrected
for oxygen sensor feedback.
CALC LOAD (CALCULATED LOAD VALUE, %)
Engine load displayed as a percentage of maximum
possible load. Value is calculated mathematically us-
ing the formula: actual (current) intake air volume

maximum possible intake air volume x 100%.
COOLANT TEMP.
(ENGINE COOLANT TEMPERATURE, C, F)
It is detected by engine coolant temp. sensor
SHORT FT B1 (SHORT TERM FUEL TRIM, %)
Short term fuel trim value represents short term
corrections to the air / fuel mixture computation. A val-
ue of 0 indicates no correction, a value greater than
0 means an enrichment correction, and a value less
than 0 implies an enleanment correction.
LONG FT B1 (LONG TERM FUEL TRIM, %)
Long term fuel trim Value represents long term correc-
tions to the air / fuel mixture computation. A value of 0
indicates no correction, a value greater than 0 means
an enrichment correction, and a value less than 0 im-
plies an enleanment correction.
MAP (INTAKE MANIFOLD ABSOLUTE
PRESSURE, kPa, inHg)
It is detected by manifold absolute pressure sensor and
used (among other things) to compute engine load.
ENGINE SPEED (rpm)
It is computed by reference pulses from crankshaft
position sensor.
VEHICLE SPEED (km / h, MPH)
It is computed based on pulse signals from vehicle
speed sensor.
IGNITION ADVANCE
(IGNITION TIMING ADVANCE FOR NO.1
CYLINDER, )
Ignition timing of NO.1 cylinder is commanded by
ECM (PCM). The actual ignition timing should be
checked by using the timing light.
INTAKE AIR TEMP. (C, F)
It is detected by intake air temp. sensor and used to
determine the amount of air passing into the intake
manifold as air density varies with temperature.
MAF (MASS AIR FLOW RATE, gm / s, lb / min)
It represents total mass of air entering intake manifold
which is computed based on signals from MAP sen-
sor, IAT sensor, TP sensor, etc.
THROTTLE POS
(ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is fully closed position,
throttle opening is indicated as 0% and 100% full open
position.
OXYGEN SENSOR B1 S1
(HEATED OXYGEN SENSOR-1, V)
It indicates output voltage of HO2S-1 installed on ex-
haust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2
(HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on ex-
haust pipe (post-catalyst). It is used to detect catalyst
deterioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM (PCM) internal pa-
rameter which indicates the ECM (PCM) requested
idle. If the engine is not running, this number is not valid.
TP SENSOR VOLT (THROTTLE POSITION
SENSOR OUTPUT VOLTAGE, V)
The Throttle Position Sensor reading provides throttle
valve opening information in the form of voltage.
INJ PULSE WIDTH
(FUEL INJECTION PULSE WIDTH, msec.)
This parameter indicates time of the injector drive
(valve opening) pulse which is output from ECM
(PCM) (but injector drive time of NO.1 cylinder for
multiport fuel injection).
IAC FLOW DUTY (IDLE AIR (SPEED) CONTROL
DUTY, %)
This parameter indicates current flow time rate within
a certain set cycle of IAC valve (valve opening rate)
which controls the amount of bypass air (idle speed).
TOTAL FUEL TRIM (%)
The value of Total Fuel Trim is obtained by putting val-
ues of short Term Fuel Trim and Long Term Fuel Trim
together. This value indicates how much correction is
necessary to keep the air / fuel mixture stoichiomet-
rical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage in-
putted from main relay to ECM (PCM).

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-57
Fig. 1 for Step 3
DTC P0134 HEATED OXYGEN SENSOR (HO2S) CIRCUIT NO ACTIVITY
DETECTED (SENSOR-1)
CIRCUIT DESCRIPTION – Refer to DTC P0130 section.
DTC DETECTING CONDITIONPOSSIBLE CAUSE

Engine warmed up.

While running under other than high load and high
engine speed conditions or at specified idle speed
(engine is in closed loop condition), HO2S-1 output
voltage is high or low continuously.
2 driving cycle detection logic, Continuous
monitoring.
“G” or “R” circuit open or short

Heated oxygen sensor malfunction

Fuel system malfunction

Exhaust gas leakage
DTC CONFIRMATION PROCEDURE – Refer to DTC P0130 section.
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE
DIAG. FLOW
TABLE”.
2Is there DTC(s) other than Fuel system
(DTC P0171 / P0172) and HO2S-1 (DTC P0134)?Go to applicable
DTC Diag. Flow
Table.Go to Step 3.
3Check HO2S-1 and Its Circuit.
1) Connect scan tool to DLC with ignition switch OFF.
2) Warm up engine to normal operating temperature and
keep it at 2000 r / min. for 60 sec.
3) Repeat racing engine (Repeat depressing accelerator
pedal 5 to 6 times continuously and take foot off from
pedal to enrich and enlean A / F mixture). See Fig. 1.
Does HO2S-1 output voltage deflect between 0.3 V and
over 0.6 V repeatedly?Go to DTC P0171
and P0172 Diag.
Flow Table (Fuel
System Check).Check “R” and “G”
wires for open
and short, and
connections for
poor connection.
If wires and
connections are
OK, replace
HO2S-1.

6-1-60 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
To other sensor
Main
fuseIgnition
switch
Heater
To HO2S-1
heater
DTC P0136 HEATED OXYGEN SENSOR (HO2S) CIRCUIT MALFUNCTION
(SENSOR-2)
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
DTC will set when A or B condition is detected.
A. Max. output voltage of HO2S-2 is lower than specified value or
Min. output voltage is higher than specified value while vehicle
driving.
B. Engine is warmed up and HO2S-2 voltage is 4.5 V or more.
(circuit open)
2 driving cycle detection logic, monitoring once / 1 driving.
Exhaust gas leakage

“G” or “R” circuit open or short

Heated oxygen sensor-2 malfunction

Fuel system malfunction

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-61
Usual driving: Driving at 30 – 40 mph, 50 – 60 km/h including short stop according to traffic signal. (under driving condition other than high-load,
high-engine speed, rapid accelerating and decelerating)1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11)and 50 mph
(80 km / h)
Above 20 mph
(32 km / h) Usual driving
DTC CONFIRMATION PROCEDURE
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, on a level road.
1) Turn ignition switch OFF.
Clear DTC with ignition switch ON, check vehicle and environmental condition for:
–Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Intake air temp.: –10C, 14F or higher
–No exhaust gas leakage and loose connection
2) Warm up engine to normal operating temperature.
3) Drive vehicle under usual driving condition for 5 min. and check HO2S-2 output voltage and “short term fuel
trim” with “Data List” mode on scan tool, and write it down.
4) Stop vehicle (don’t turn ignition switch OFF).
5) Increase vehicle speed to higher than 20 mph, 32 km / h and then stop vehicle.
6) Repeat above steps 5) 4 times.
7) Increase vehicle speed to about 50 mph (80 km / h) in 3rd gear or 2 range.
8) Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) for 10sec.
or more.
9) Stop vehicle (don’t turn ignition switch OFF) and run engine at idle for 2 min.
After this step 9), if “Oxygen Sensor Monitoring TEST COMPLETED” is displayed in “READINESS TESTS”
mode and DTC is not displayed in “DTC” mode, confirmation test is completed.
If “TEST NOT COMPLTD” is still being displayed, proceed to next step 10).
10) Drive vehicle under usual driving condition for 10 min. (or vehicle is at a stop and run engine at idle for 10 min.
or longer)
11) Stop vehicle (don’t turn ignition switch OFF). Confirm test results according to “Test Result Confirmation Flow
Table” in “DTC CONFIRMATION PROCEDURE” of DTC P0420.

6-1-62 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check exhaust system for leakage, loose
connection and damage.
Is it good condition?Go to Step 3.Repair or replace.
3Check HO2S-2 and Its Circuit.
Was HO2S-2 output voltage indicated on scan
tool in step 3) of DTC confirmation test less
than 1.275 V?Go to Step 4.“G” or “R” circuit open or
HO2S-2 malfunction.
4Check Short Term Fuel Trim.
Did short term fuel trim very within –20 – + 20%
range in step 3) of DTC confirmation test?Check “R” and “G” wire
for open and short, and
connection for poor
connection. If wire and
connection are OK,
replace HO2S-2.Check fuel system. Go
to DTC P0171 / P0172
Diag. Flow Table.