2000 SUZUKI SWIFT sensor

6-26 ENGINE GENERAL INFORMATION AND DIAGNOSIS
ENGINE DIAGNOSIS TABLE
Perform troubleshooting referring to following table when ECM has detected no DTC and no abnormality has
been found in visual inspection and engine basic inspection previously.
Condition Possible Cause Correction
Hard Starting
(Engine cranks OK) Faulty spark plug Spark plugs in Section 6F1.
Leaky high-tension cord High-tension cords in Section 6F1.
Loose connection or disconnection of high-
tension cords or lead wiresHigh-tension cords in Section 6F1.
Faulty ignition coil Ignition coil in Section 6F1.
Dirty or clogged fuel hose or pipe Diagnostic Flow Table B-3.
Malfunctioning fuel pump Diagnostic Flow Table B-3.
Air inhaling from intake manifold gasket or
throttle body gasket
Faulty idle air control system Diagnostic Flow Table B-4.
Faulty ECT sensor or MAP sensor ECT sensor or MAP sensor in Section
6E1.
Faulty ECM
Hard Starting
(Engine cranks OK) Poor spark plug tightening or faulty gasket Spark plugs in Section 6F1.
Compression leak from valve seat Valves inspection in Section 6A1.
Sticky valve stem Valves inspection in Section 6A1.
Weak or damaged valve springs Valve springs inspection in Section
6A1.
Compression leak at cylinder head gasket Cylinder head inspection in Section
6A1.
Sticking or damaged piston ring Cylinders, pistons and piston rings
inspection in Section 6A1.
Worn piston, ring or cylinder Cylinders, pistons and piston rings
inspection in Section 6A1.
Malfunctioning PCV valve PCV system in Section 6E1.
Low compression Compression check in Section 6A1.
Low oil pressure
Improper oil viscosity Engine oil and oil filter change in Sec-
tion 0B.
Malfunctioning oil pressure switch Oil pressure switch inspection in Sec-
tion 8.
Clogged oil strainer Oil pan and oil pump strainer cleaning
in Section 6A1.
Functional deterioration of oil pump Oil pump in Section 6A1.
Worn oil pump relief valve Oil pump in Section 6A1.
Excessive clearance in various sliding parts

6-28 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Poor gasoline mile-
age Leaks or loose connection of high-tension
cordHigh-tension cords in Section 6F1.
Faulty spark plug (improper gap, heavy
deposits and burned electrodes, etc.)Spark plugs in Section 6F1.
Malfunctioning EGR valve (if equipped) EGR system in Section 6E1.
High idle speed Refer to item “Improper engine idle
speed” previously outlined.
Poor performance of TP sensor, ECT sensor
or MAP sensorTP sensor, ECT sensor or MAP sensor
in Section 6E1.
Faulty EGR valve (if equipped) EGR system in Section 6E1.
Faulty fuel injector(s) Diagnostic Flow Table B-1.
Faulty ECM
Poor valve seating Valves inspection in Section 6A1.
Dragging brakes Trouble diagnosis in Section 5.
Slipping clutch Trouble diagnosis in Section 7C.
Thermostat out of order Thermostat in Section 6B.
Improper tire pressure Refer to Section 3F.
Low Compression Previously outlined
Excessive engine
oil consumption Blown cylinder head gasket Cylinder head in Section 6A1.
Leaky camshaft oil seals Camshaft in Section 6A1.
Sticky piston ring Piston cleaning in Section 6A1.
Worn piston and cylinder Pistons and cylinders inspection in Sec-
tion 6A1.
Worn piston ring groove and ring Pistons inspection in Section 6A1.
Improper location of piston ring gap Pistons assembly in Section 6A1.
Worn or damaged valve stem seal Valves removal and installation in Sec-
tion 6A1.
Worn valve stem Valves inspection in Section 6A1.
Engine hesitates
(Momentary lack of
response as accel-
erator is depressed.
Can occur at all
vehicle speeds.
Usually most severe
when first trying to
make vehicle move,
as from a stop sign.)Spark plug faulty or plug gap out of adjust-
mentSpark plugs in Section 6F1.
Leaky high-tension cord High-tension cords in Section 6F1.
Fuel pressure out of specification Diagnostic Flow Table B-3.
Malfunctioning EGR valve (if equipped) EGR system in section 6E1.
Poor performance of TP sensor, ECT sensor
or MAP sensorTP sensor, ECT sensor or MAP sensor
in Section 6E1.
Faulty fuel injector Diagnostic Flow Table B-1.
Faulty ECM
Engine overheating Refer to “Overheating” section.
Low compression Previously outlined.
Surge
(Engine power vari-
ation under steady
throttle or cruise.
Feels like vehicle
speeds up and
down with no
change in accelera-
tor pedal.)Leaky or loosely connected high-tension cord High-tension cords in Section 6F1.
Faulty spark plug (excess carbon deposits,
improper gap, and burned electrodes, etc.)Spark plugs in Section 6F1.
Variable fuel pressure Diagnostic Flow Table B-3.
Kinky or damaged fuel hose and lines
Faulty fuel pump (clogged fuel filter)
Malfunctioning EGR valve EGR system in Section 6E1.
Poor performance of MAP sensor MAP sensor in Section 6E1.
Faulty fuel injector Diagnostic Flow Table B-1.
Faulty ECM Condition Possible Cause Correction

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-29
Excessive detona-
tion
(Engine makes con-
tinuously sharp
metallic knocks that
change with throttle
opening. Sounds
like pop corn pop-
ping.)Faulty spark plug Spark plugs in Section 6F1.
Loose connection of high-tension cord High-tension cords in Section 6F1.
Engine overheating Refer to “Overheating” section.
Clogged fuel filter (faulty fuel pump) or fuel
linesDiagnostic Flow Table B-1 or B-2.
Air inhaling from intake manifold or throttle
body gasket
Malfunctioning EGR valve (if equipped) EGR system in Section 6E1.
Poor performance of knock sensor, ECT sen-
sor or MAP sensorKnock sensor in Section 6, ECT sensor
or MAP sensor in Section 6E1.
Faulty fuel injector(s) Diagnostic Flow Table B-1.
Faulty ECM
Excessive combustion chamber deposits Piston and cylinder head cleaning in
Section 6A1.
Engine has no
powerFaulty spark plug Spark plugs in Section 6F1.
Faulty ignition coil with ignitor Ignition coil in Section 6F1.
Leaks, loose connection or disconnection of
high-tension cordHigh-tension cords in Section 6F1.
Faulty knock sensor Knock sensor malfunction in this sec-
tion.
Clogged fuel hose or pipe Diagnostic Flow Table B-3.
Malfunctioning fuel pump Diagnostic Flow Table B-2.
Air inhaling from intake manifold gasket or
throttle body gasket
Engine overheating Refer to “Overheating” section.
Engine has no
powerMalfunctioning EGR valve (if equipped) EGR system inspection in Section 6E1.
Maladjusted accelerator cable play Accelerator cable play in Section 6E1.
Poor performance of TP sensor, ECT sensor
or MAP sensorTP sensor, ECT sensor or MAP sensor
in Section 6E1.
Faulty fuel injector(s) Diagnostic Flow Table B-1.
Faulty ECM
Dragging brakes Trouble diagnosis in Section 5.
Slipping clutch Trouble diagnosis in Section 7C.
Low compression Previously outlined. Condition Possible Cause Correction

6-30 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Improper engine
idling or engine fails
to idleFaulty spark plug Spark plugs in Section 6F1.
Leaky or disconnected high-tension cord High-tension cords in Section 6F1.
Faulty ignition coil with ignitor Ignition coil in Section 6F1.
Fuel pressure out of specification Diagnostic Flow Table B-3.
Leaky manifold, throttle body, or cylinder
head gasket
Malfunctioning EGR valve (if equipped) EGR system in Section 6E1.
Faulty idle air control system Diagnostic Flow Table B-4.
Faulty evaporative emission control system EVAP control system in Section 6E1.
Faulty EGR system (if equipped) EGR system in Section 6E1.
Faulty fuel injector(s) Diagnostic Flow Table B-1.
Poor performance of ECT sensor, TP sensor
or MAP sensorECT sensor, TP sensor or MAP sensor
in Section 6E1.
Faulty ECM
Loose connection or disconnection of vacuum
hoses
Malfunctioning PCV valve PCV system in Section 6E1.
Engine overheating Refer to “Overheating” section.
Low compression Previously outlined.
Excessive hydrocar-
bon (HC) emission
or carbon monox-
ide (CO)Faulty spark plug Spark plugs in Section 6F1.
Leaky or disconnected high-tension cord High-tension cords in Section 6F1.
Faulty ignition coil with ignitor Ignition coil assembly in Section 6F1.
Low compression Refer to “Low compression” section.
Lead contamination of three way catalytic
converterCheck for absence of filler neck restric-
tor.
Faulty evaporative emission control system EVAP control system in Section 6E1.
Fuel pressure out of specification Diagnostic Flow Table B-3.
Closed loop system (A/F feed back compen-
sation) fails
Faulty TP sensor
Poor performance of ECT sensor or MAP
sensorTP sensor in Section 6E1.
ECT sensor or MAP sensor in Section
6E1.
Faulty injector(s) Diagnostic Flow Table B-1
Faulty ECM
Engine not at normal operating temperature
Clogged air cleaner
Vacuum leaks
Excessive nitrogen
oxides (NOx) emis-
sionImproper ignition timing See section 6F1.
Lead contamination of catalytic converter Check for absence of filler neck restric-
tor.
Faulty EGR system (if equipped) EGR system in Section 6E1.
Fuel pressure out of specification Diagnostic Flow Table B-3.
Closed loop system (A/F feed back compen-
sation) fails
Faulty TP sensor
Poor performance of ECT sensor or MAP
sensorTP sensor in Section 6E1.
ECT sensor or MAP sensor in Section
6E1.
Faulty injector(s) Diagnostic Flow Table B-1
Faulty ECM Condition Possible Cause Correction

6-32 ENGINE GENERAL INFORMATION AND DIAGNOSIS
✱THROTTLE POS
(ABSOLUTE THROTTLE
POSITION)Ignition switch
ON/engine
stoppedThrottle valve fully closed 7 – 18%
Throttle valve fully open 70 – 90%
✱O2S B1 S1
(HEATED OXYGEN SEN-
SOR-1)At specified idle speed after warming up 0.01 – 0.95 V
∆✱O2S B1 S2
(HEATED OXYGEN SEN-
SOR-2)When engine is running at 2000 r/min. for 3
min or longer after warming up.0.01 – 0.95 V
∆✱O2S FT B1 S1 At specified idle speed after warning up– 20 – +20%
∆✱DIS. WITH MIL ON––
DESIRED IDLE
(DESIRED IDLE SPEED)At idling with no load after warming up, M/T
at neutral, A/T at “P” rangeM/T 700 r/min
A/T 750 r/min
TP SENSOR VOLT
(THROTTLE POSITION
SENSOR OUTPUT VOLT-
AGE)Ignition switch
ON/engine
stoppedThrottle valve fully closed More than 0.2 V
Throttle valve fully open Less than 4.8 V
INJ PULSE WIDTH
(FUEL INJECTION PULSE
WIDTH)At specified idle speed with no load after
warming up2.0 – 3.6 msec.
At 2500 r/min with no load after warming up 2.0 – 3.6 msec.
IAC FLOW DUTY
(IDLE AIR CONTROL
FLOW DUTY)At idling with no load after warming up 5 – 25%
TOTAL FUEL TRIM At specified idle speed after warming up– 35 – +35%
BATTERY VOLTAGE Ignition switch ON/engine stop 12 – 14 V
CANIST PRG DUTY
(EVAP CANISTER PURGE
FLOW DUTY)–0 – 100%
CLOSED THROT POS
(CLOSED THROTTLE
POSITION)Throttle valve at idle position ON
Throttle valve opens larger than idle posi-
tionOFF
FUEL CUT When engine is at fuel cut condition ON
Other than fuel cut condition OFF
RADIATOR FAN
(RADIATOR FAN CON-
TROL RELAY)Ignition switch
ONEngine coolant temp. :
Lower than 95°C (203°F)OFF
Engine coolant temp. :
97.5°C (208°F) or higherON
ELECTRIC LOAD Ignition switch ON/Headlight, small light
and rear window defogger all turned OFFOFF
Ignition switch ON/Headlight, small light or
rear window defogger turned ONON
A/C SWITCH Engine running after warming up, A/C not
operatingOFF
Engine running after warming up, A/C oper-
atingON SCAN TOOL DATA VEHICLE CONDITION NORMAL CONDITION/
REFERENCE VALUES

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-33
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 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 using 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 value of 0 indi-
cates 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 corrections to the air/fuel mixture computation. A value of 0 indi-
cates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies 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.PNP SIGNAL (PARK/NEU-
TRAL POSITION SIGNAL)
A/T onlyIgnition switch
ONSelector lever in “P” or “N”
positionP/N Range
Selector lever in “R”, “D”,
“2” or “L” positionD Range
EGR VALVE At specified idle speed after warming up 0%
∆FUEL TANK LEVEL–0 – 100%
BAROMETRIC PRESS–Display the barometric pres-
sure
FUEL PUMP Within 3 seconds after ignition switch ON or
engine runningON
Engine stop at ignition switch ON. OFF
BRAKE SW Ignition switch
ONBrake pedal is depressing ON
Brake pedal is releasing OFF
BLOWER FAN Ignition switch
ONBlower fan switch ON ON
Blower fan switch OFF OFF
A/C MAG CLUTCH Ignition switch
ONA/C switch ON ON
A/C switch OFF OFF SCAN TOOL DATA VEHICLE CONDITION NORMAL CONDITION/
REFERENCE VALUES

6-34 ENGINE GENERAL INFORMATION AND DIAGNOSIS
IGNITION ADVANCE (IGNITION TIMING ADVANCE FOR NO.1 CYLINDER, °)
Ignition timing of NO.1 cylinder is commanded by ECM. 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 sensor,
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 exhaust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2 (HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on exhaust pipe (post-catalyst). It is used to detect catalyst dete-
rioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM internal parameter which indicates the ECM 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 (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 values 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 stoichiometrical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage inputted from main relay to ECM.
CANIST PURGE DUTY (EVAP CANISTER PURGE FLOW DUTY, %)
This parameter indicates valve ON (valve open) time rate within a certain set cycle of EVAP purge solenoid
valve which controls the amount of EVAP purge.
0% means that the purge valve is completely closed while 100% is a fully open valve.
CLOSED THROTTLE POSITION (ON/OFF)
This parameter will read ON when throttle valve is fully closed, or OFF when the throttle is not fully closed.
FUEL CUT (ON/OFF)
ON : Fuel being cut (output signal to injector is stopped)
OFF : Fuel not being cut

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-35
RADIATOR FAN (RADIATOR FAN CONTROL RELAY, ON/OFF)
ON : Command for radiator fan control relay operation being output.
OFF : Command for relay operation not being output.
ELECTRIC LOAD (ON/OFF)
ON : Headlight, small light or rear window defogger ON signal inputted.
OFF : Above electric loads all turned OFF.
A/C SWITCH (ON/OFF)
ON : Command for A/C operation being output from ECM to A/C compressor magnet clutch.
OFF : Command for A/C operation not being output.
FUEL TANK LEVEL (%)
This parameter indicates approximate fuel level in the fuel tank. As the detectable range of the fuel level sensor
is set as 0 to 100%, however, with some models whose fuel tank capacity is smaller, the indicated fuel level may
be only 70% even when the fuel tank is full.
PNP SIGNAL (PARK/NEUTRAL POSITION SIGNAL, P/N RANGE or D RANGE)
It is detected by signal from TCM.
D range : A/T is in “R”, “D”, “2” or “L” range.
P/N range : A/T is in “P” or “N” range or the above signal is not inputted from TCM.
EGR VALVE (%)
This parameter indicates opening rate of EGR valve which controls the amount of EGR flow.