2000 SUZUKI SWIFT fuel

Ignition coil
Igniter
Ignition switch
Main
fuse
Injector resistor
Fuel injector
Crankshaft
position sensor
Camshaft
position sensor
Ground
at engine “I / G COIL METER”
Main relay
6-68 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
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
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.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-69
Below
specified value DTC DETECTING CONDITION
POSSIBLE 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
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.
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)
–Ambient temp.: –10C, 14F or higher
–Intake air temp.: 70C, 158F or lower
–Engine coolant temp.: –10 – 11 0C, 14 – 230F
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”.

6-70 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE
DIAG. FLOW
TABLE“.
2Is there DTC other than Fuel system (DTC P0171 / P0172)
and misfire (DTC P0300-P0303)?Go to applicable
DTC Diag.
Flow Table.Go to Step 3.
3Check Ignition System.
1) Remove spark plugs and check them for;

Air gap: 1.0 – 1.1 mm (0.040 – 0.043 in.) See Fig. 1.

Carbon deposits

Insulator damage

Plug type
If abnormality is found, adjust, clean or replace.
2) Disconnect injector connector. See Fig. 2.
3) Connect spark plugs to high tension cords and then
ground spark plugs.
4) Crank engine and check that each spark plug sparks.
Are above check results satisfactory?Go to Step 4.Check ignition
system parts
(Refer to Section
6F).
4Check Fuel Pressure (Refer to Section 6E1 for details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge. See Fig. 3.
3) Check fuel pressure.
With fuel pump operating
and engine at stop : 160 – 210 kPa, 1.6 – 2.1 kg / cm
2,
22.7 – 29.9 psi.
At specified idle speed : 90 – 140 kPa, 0.9 – 1.4 kg / cm
2,
12.8 – 20.0 psi.
Is measured value as specified?
Go to Step 5.Go to Diag. Flow
Table B-3 fuel
pressure check.
5Check Fuel Injector and Circuit.
1) Turn ignition switch OFF and disconnect fuel injector
connector.
2) Check for proper connection to fuel injector at each terminal.
3) If OK, then check injector resistance. See Fig. 4.
Injector resistance: 0.5 – 1.5 Ω at 20C (68F).
4) Connect injector connector.
5) Check that fuel is injected out in conical shape from fuel
injector when running engine.
6) Check injector for fuel leakage after engine stop.
Fuel leakage: Less than 1 drop / min.
Is check result satisfactory?Go to Step 6.Check injector
circuit or replace
fuel injector.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-71
1. Throttle body
2. Fuel feed hose
GoodNo good1. Injector connector
STEPACTIONYESNO
6Check PCV valve for clogging (See Section 6E1).
Is it in good condition?Go to Step 7.Replace PCV valve.
7Check EVAP Canister Purge Valve for Closing.
1) Disconnect purge hose (1) from EVAP canister.
2) Place finger against the end of disconnected hose.
3) Check that vacuum is not felt there, when engine is
cool and running at idle. See Fig. 5.
Is vacuum felt?Check EVAP
control system
(See Section 6E1).Go to Step 8.
8Check intake manifold pressure sensor for performance
(See Section 6E1).
Is it in good condition?Go to Step 9.Repair or replace.
9Check engine coolant temp. sensor for performance
(See Section 6E1).
Is it in good condition?Go to Step 10.Replace engine
coolant temp.
sensor.
10Check parts or system which can cause engine rough
idle or poor performance.
–Engine compression (See Section 6A).
–Valve lash (See Section 6A).
–Valve timing (Timing belt installation. See Section 6A).
Are they in good condition?Check wire harness
and connection of
ECM (PCM) ground,
ignition system and
fuel injector for
intermittent open
and short.Repair or replace.
Fig. 1 for Step 3 Fig. 2 for Step 3 Fig. 3 for Step 4
Fig. 4 for Step 5 Fig. 5 for Step 7

Display of fuel injection signal using oscilloscope
1. CMP sensor signal
2. Fuel injector signal
3. Fuel injection time
2V/Div.
20V/Div.1
2
10ms/Div
Waveforms at specified idle speed 3 Sensor rotor
in distributorCamshaft
position sensor
6-74 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0340 CAMSHAFT POSITION (CMP) SENSOR CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

No CMP sensor signal for 2 seconds at engine
cranking (CKP sensor signal is inputted).
CMP sensor circuit open or short.

Signal rotor teeth damaged.

CMP sensor malfunction, foreign material being
attached or improper installation.

ECM (PCM) malfunction.
Reference
Connect oscilloscope between terminals C01-2 and C01-10 of ECM (PCM) connector connected to ECM (PCM)
and check CMP sensor signal.
DTC CONFIRMATION PROCEDURE
1) Clear DTC.
2) Start engine and keep it at idle for 1 min.
3) Select “DTC” mode on scan tool and check DTC.

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

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-77
1) 2) 3) 4) 35 – 45 mph
(55 – 65 km / h)
30 – 40 mph
(50 – 60 km / h)
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 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)
–Ambient temp.: –10C, 14F or higher
–Intake air temp.: 70C, 158F or lower
–Engine coolant temp.: 70 – 11 0C, 158 – 230F
2) Start engine and drive vehicle at 40 – 47 mph, 65 – 75 km / h for 15 min. or longer.
While this driving, if “Catalyst 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, continue test driving.
3) Decrease vehicle speed at 28 – 34 mph, 45 – 55 km / h, and hold throttle valve at that opening position for 2 min.
and confirm that short term fuel trim vary within –20% –+20% range.
4) Stop vehicle (do not turn ignition switch OFF) and confirm test results according to following “Test Result Con-
firmation Flow Table”.
Test Result Confirmation Flow Table
STEPACTIONYESNO
1Check DTC in “DTC” mode and pending DTC in
“ON BOARD TEST” or “PENDING DTC” mode.
Is DTC or pending DTC displayed?Proceed to applicable
DTC Diag. Flow Table.Go to Step 2.
2Set scan tool to “READINESS TESTS” mode and
check if testing has been completed.
Is test completed?No DTC is detected
(confirmation test is
completed).Repeat DTC
confirmation
procedure.

6-78 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check Short Term Fuel Trim.
Did short term fuel trim vary within –20% –+20%
range in step 3) of DTC confirmation test?Go to Step 3.Check fuel system.
Go to DTC P0171 / P0172
Diag. Flow Table.
3Check HO2S-2 for Output Voltage.
Perform steps 1) through 9) of DTC confirmation
procedure for DTC P0136 (HO2S-2 malfunction)
and check output voltage of HO2S-2 then.
Is over 0.6 V and below 0.3 V indicated?Replace three way
catalytic converter.Check “G” and “R”
wires for open and
short, and connections
for poor connection.
If wires and connections
are OK, replace
HO2S-2.