2000 SUZUKI SWIFT ECU

ENGINE AND EMISSION CONTROL SYSTEM 6E1-29
INTAKE AIR TEMPERATURE SENSOR (IAT SENSOR)
REMOVAL
1) Disconnect battery negative cable at battery.
2) Disconnect coupler (1) from IAT sensor.
3) Remove IAT sensor from air cleaner case (2).
INSPECTION
Immerse temperature sensing part of IAT sensor in water (or ice)
and measure resistance between sensor terminals while heating
water gradually.
If measured resistance does not show such characteristic as
shown in left figure, replace IAT sensor.
INSTALLATION
Reverse removal procedure noting the following.
Clean mating surfaces of IAT sensor and air cleaner case.
Connect IAT sensor connector (1) securely.
1
2
1

6E1-30 ENGINE AND EMISSION CONTROL SYSTEM
ENGINE COOLANT TEMPERATURE SENSOR (ECT
SENSOR)
REMOVAL
1) Disconnect battery negative cable at battery.
2) Drain coolant referring to Section 6B.
3) Remove air intake pipe.
4) Disconnect connector from ECT sensor.
5) Remove ECT sensor (1) from thermostat case.
INSPECTION
Immerse temperature sensing part of ECT sensor (1) in water (or
ice) and measure resistance between terminal “A” and “B” while
heating water gradually.
If measured resistance does not show such characteristic as
shown in left figure, replace ECT sensor (1).
INSTALLATION
Reverse removal procedure noting the following:
Clean mating surfaces of ECT sensor (1) and thermostat
case.
Check O-ring for damage and replace if necessary.
Tighten ECT sensor (1) to specified torque.
Tightening torque
ECT sensor (a) : 15 N·m (1.5 kg-m, 11.5 lb-ft)
Connect connector to ECT sensor (1) securely.
Refill coolant referring to Section 6B. WARNING:
To help avoid danger of being burned, do not remove
radiator cap while engine and radiator are still hot.
Scalding fluid and steam can be blown out under pres-
sure if cap is taken off too soon.
1
1, (a)

ENGINE AND EMISSION CONTROL SYSTEM 6E1-31
HEATED OXYGEN SENSOR (HO2S-1 AND HO2S-2)
OXYGEN SENSOR HEATER INSPECTION
1) Disconnect sensor connector.
2) Using ohmmeter, measure resistance between terminals
“V
B” and “GND” of sensor connector.
If found faulty, replace oxygen sensor.
Resistance of oxygen sensor heater
HO2S-1 : 5.0 – 6.4
Ω at 20°C (68°F)
HO2S-2 : 11.7 – 14.3
Ω at 20°C (68°F)
3) Connect sensor connector securely.
REMOVAL
1) Disconnect negative cable at battery.
2) For HO2S-1, disconnect connector of heated oxygen sensor
and release its wire harness from clamps, then remove front
bumper and heat insulator panel.
3) For HO2S-2, disconnect connector of heated oxygen sensor
and release its wire harness from clamp and hoist vehicle.
4) Remove heated oxygen sensor (1) from exhaust manifold or
exhaust pipe.
INSTALLATION
Reverse removal procedure noting the following.
Tighten heated oxygen sensor (1) to specified torque.
Tightening torque
Heated oxygen sensor (a) : 45 N·m (4.5 kg-m, 32.5 lb-ft)
Connect connector of heated oxygen sensor (1) and clamp
wire harness securely.
After installing heated oxygen sensor (1), start engine and
check that no exhaust gas leakage exists. NOTE:
Temperature of sensor affects resistance value largely.
Make sure that sensor heater is at correct temperature.
1. Viewed from terminal side
WARNING:
To avoid danger of being burned, do not touch exhaust
system when system is hot. Oxygen sensor removal
should be performed when system is cool.
[A] : HO2S-1
[B] : HO2S-2

6E1-32 ENGINE AND EMISSION CONTROL SYSTEM
CAMSHAFT POSITION SENSOR
INSPECTION
Check camshaft position sensor referring to DTC P0340 (No.15)
Diag. Flow Table in Section 6. If malfunction is found, replace.
REMOVAL
1) Disconnect negative cable at battery.
2) Disconnect connector from camshaft position sensor.
3) Remove camshaft position sensor from cylinder head.
INSTALLATION
1) Check that O-ring is free from damage.
2) Check that camshaft position sensor and signal rotor teeth
are free from any metal particles and damage.
3) Install camshaft position sensor to cylinder head.
Tightening torque
Camshaft position sensor bolt
(a) : 10 N·m (1.0 kg-m, 7.5 lb-ft)
4) Connect connector to it securely.
5) Connect negative cable to battery.
CRANKSHAFT POSITION SENSOR
INSPECTION
Check crankshaft position sensor referring to step 1 and 2 of DTC
P0335 (No.23) Flow Table. If malfunction is found, replace.
REMOVAL
1) Disconnect negative cable at battery.
2) Remove generator drive belt, loosen pivot bolt and move
generator outward.
3) Disconnect connector from crankshaft position sensor.
4) Remove crankshaft position sensor (1) from cylinder block.
INSTALLATION
1) Check to make sure that crankshaft position sensor and pul-
ley teeth are free from any metal particles and damage.
2) Install crankshaft position sensor to cylinder block.
3) Connect connector to it securely.
4) Adjust generator belt tension, refer to Section 6B.
5) Connect negative cable to battery.

IGNITION SYSTEM (ELECTRONIC IGNITION SYSTEM 6F1-3
SYSTEM WIRING DIAGRAM
DIAGNOSIS
1. Ignition switch 7. No.1 spark plug
2. Main relay 8. No.2 spark plug
3. Ignition coil assembly for No.1 and No.4 spark plugs 9. No.3 spark plug
4. Ignition coil assembly for No.2 and No.3 spark plugs 10. No.4 spark plug
5. CMP sensor 11. Sensed information (MAP sensor, ECT sensor, IAT sensor, TP sensor, Knock sensor (if
equipped), VSS, Park/Neutral position signal, Electric load signal, Engine start signal, Test switch
terminal (Vehicle without immobilizer indicator lamp))
6. CKP sensor
Condition Possible Cause Correction
Engine cranks, but will
not start or hard to
start (No spark)Blown fuse for ignition coil Replace.
Loose connection or disconnection of lead wire
or high-tension cord(s)Connect securely.
Faulty high-tension cord(s) Replace.
Faulty spark plug(s) Adjust, clean or replace.
Faulty ignition coil Replace ignition coil assembly.
Faulty CKP sensor or CKP sensor plate Clean, tighten or replace.
Faulty ECM Replace.
Poor fuel economy or
engine performanceIncorrect ignition timing Check related sensors and CKP
sensor plate.
Faulty spark plug(s) or high-tension cord(s) Adjust, clean or replace.
Faulty ignition coil assembly Replace.
Faulty CKP sensor or CKP sensor plate Clean, tighten or replace.
Faulty ECM Replace.

6F1-4 IGNITION SYSTEM (ELECTRONIC IGNITION SYSTEM)
IGNITION SYSTEM DIAGNOSTIC FLOW TABLE
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” in Section 6 per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE” in Sec-
tion 6.
2Ignition Spark Test
1) Check all spark plugs for condition and type refer-
ring to “Spark Plugs” section.
2) If OK, perform ignition spark test, referring to “Igni-
tion Spark Test” in this section.
Is spark emitted from all spark plugs?Go to Step 11. Go to Step 3.
3Diagnostic Trouble Code (DTC) Check Is DTC stored
in ECM?Go to applicable DTC
Diag. Flow Table in
Section 6.Go to Step 4.
4Electrical Connection Check
1) Check ignition coil assemblies and high-tension
cords for electrical connection.
Are they connected securely?Go to Step 5. Connect securely.
5High-tension Cords Check
1) Check high-tension cord for resistance referring to
“High-Tension Cords” in this section.
Is check result satisfactory?Go to Step 6. Replace high-tension
cord(s).
6Ignition Coil Assembly Power Supply and Ground Cir-
cuit Check
1) Check ignition coil assembly power supply and
ground circuits for open and short.
Are circuits in good condition?Go to Step 7. Repair or replace.
7Ignition Coil Assembly Check
1) Check ignition coil for resistance referring to “Igni-
tion Coil Assembly” in this section.
Is check result satisfactory?Go to Step 8. Replace ignition coil
assembly.
8Crankshaft Position (CKP) Sensor Check
1) Check crankshaft position sensor referring to Step
3 and 4 of “DTC P0335 (No.23) Diag. Flow Table”
in Section 6.
Is check result satisfactory?Go to Step 9. Tighten CKP sensor
bolt, replace CKP sen-
sor or CKP sensor
plate.
9Ignition Trigger Signal Circuit Check
1) Check ignition trigger signal wire for open, short
and poor connection.
Is circuit in good condition?Go to Step 10. Repair or replace.
10A Known-good Ignition Coil Assembly Substitution
1) Substitute a known-good ignition coil assembly
and then repeat Step 2.
Is check result of Step 2 satisfactory?Go to Step 11. Substitute a known-
good ECM and then
repeat Step 2.
11Ignition Timing Check
1) Check initial ignition timing and ignition timing
advance referring to “Ignition Timing” in this sec-
tion.
Is check result satisfactory?System is in good con-
dition.Check CKP sensor,
CKP sensor plate and
input signals related to
this system.

IGNITION SYSTEM (ELECTRONIC IGNITION SYSTEM 6F1-7
6) Install spark plugs and torque them to specification.
Tightening torque
Spark plug : 25 N·m (2.5 kg-m, 18.0 lb-ft)
7) Install ignition coil assemblies referring to IGNITION COIL
ASSEMBLY in this section.
8) Install high-tension cords securely by gripping their caps.
9) Install cylinder head upper cover and air intake pipe.
IGNITION COIL ASSEMBLY
(INCLUDING IGNITOR)
Inspection
1) Disconnect negative cable at battery.
2) Remove air intake pipe and cylinder head upper cover.
3) Disconnect ignition coil coupler.
4) Disconnect high-tension cord (3) from ignition coil assembly
(2).
5) Remove ignition coil bolts (1) and then pull out ignition coil
assembly.
6) Measure secondary coil for resistance.
If resistance is out of specification, replace ignition coil
assembly.
Secondary coil resistance
: 7.6 - 10.2 k
Ω at 20°C, 68°F
7) Install ignition coil assembly.
8) Tighten ignition coil bolts, and then connect ignition coil cou-
pler.
9) Install high-tension cord to ignition coil assembly while grip-
ping its cap.
10) Install cylinder head upper cover and air intake pipe.
CRANKSHAFT POSITION SENSOR
(CKP SENSOR)
Refer to Section 6E1 for removal, inspection and installation.

6H-2 CHARGING SYSTEM
GENERAL DESCRIPTION
BATTERY
The battery has three major functions in the electrical system.
It is a source of electrical energy for cranking the engine.
It acts as a voltage stabilizer for the electrical system.
It can, for a limited time, provide energy when the electrical load exceeds the output of the generator.
CARRIER AND HOLD-DOWN
The battery carrier should be in good condition so that it will support the battery securely and keep it level.
Before installing the battery, the battery carrier and hold-down clamp should be clean and free from corrosion
and make certain there are no parts in carrier.
To prevent the battery from shaking in its carrier, the hold-down bolts should be tight enough but not over-tight-
ened.
ELECTROLYTE FREEZING
The freezing point of electrolyte depends on its specific gravity. Since freezing may ruin a battery, it should be
protected against freezing by keeping it in a fully charged condition. If a battery is frozen accidentally, it should
not be charged until it is warmed.
SULFATION
If the battery is allowed to stand for a long period in discharged condition, the lead sulfate becomes converted
into a hard, crystalline substance, which will not easily turn back to the active material again during the subse-
quent recharging. “Sulfation” means the result as well as the process of that reaction. Such a battery can be
revived by very slow charging and may be restored to usable condition but its capacity is lower than before.
BUILT-IN INDICATOR (IF EQUIPPED)
The battery has a built-in temperature compensated indicator in the top of the battery. This indicator is to be
used with the following diagnostic procedure. When checking the indicator, make sure that the battery has a
clean top. A light may be needed in some poorly-lit areas.
Three types of indication available under normal operation are as
follows.
Green Dot
Battery is sufficiently charged for testing.
Dark
Battery must be charged before testing.
If there is a cranking complaint, battery should be tested as
described in Diagnosis section. Charging and electrical sys-
tems should also be checked at this time.
Clear or Light Yellow
This means that fluid level is below the bottom of hydrome-
ter. Its possible cause is excessive or prolonged charging, a
broken case, excessive tipping or normal battery deteriora-
tion. When the battery is found in such condition, it is possi-
ble that high charging voltage is caused by the faulty
charging system and therefore, charging and electrical sys-
tems need to be checked. If there is a trouble in cranking
and its cause lies in the battery, it should be replaced.