Page 184 of 557

6-1-28 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
ConditionPossible CauseReferring Item
Excessive
hydrocarbon (HC)
emission or carbon
monoxide (CO)Ignition system out of order
Faulty spark plug
Leaky or disconnected high-tension cord
Faulty ignition coil with ignitor
Low compression
Engine and emission control system out of
order
Lead contamination of three way catalytic
converter
Faulty evaporative emission control system
Fuel pressure out of specification
Closed loop system (A / F feed back
compensation) fails
–Faulty TP sensor
–Poor performance of ECT sensor or MAP
sensor
Faulty injector(s)
Faulty ECM (PCM)
Others
Engine not at normal operating temperature
Clogged air cleaner
Vacuum leaks
Spark plugs in Section 6F1
High-tension cords in Section 6F1
Ignition coil assembly in Section
6F1
Refer to “Low compression”
section
Check for absence of filler neck
restrictor
EVAP control system in Section
6E2
Diagnostic Flow Table B-3
TP sensor in Section 6E2
ECT sensor or MAP sensor in
Section 6E2
Diagnostic Flow Table B-1
Excessive nitrogen
oxides (NOx)
emissionIgnition system out of order
Improper ignition timing
Engine and emission control system out of
order
Lead contamination of catalytic converter
Faulty EGR system
Fuel pressure out of specification
Closed loop system (A / F feed back
compensation) fails
–Faulty TP sensor
–Poor performance of ECT sensor or MAP
sensor
Faulty injector(s)
Faulty ECM (PCM)
See section 6F1
Check for absence of filler neck
restrictor.
EGR system in Section 6E2
Diagnostic Flow Table B-3
TP sensor in Section 6E2
ECT sensor or MAP sensor in
Section 6E2
Diagnostic Flow Table B-1
Page 225 of 557

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.
Page 237 of 557

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-81
Oscilloscope WaveformsHeated
oxygen
sensor-1To other sensor
Heated oxygen
sensor-2
Warm up three way
catalytic converterThree way catalytic converter
Engine running at
Closed loop conditionFuel
CutIdle after fuel cut 0.5 V / Div
2 sec. / Div
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
Page 239 of 557
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-83
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 “R” and “G” wires
for open and short, and
connections for poor
connection.
If wires and connections
are OK, replace
HO2S-2.
Page 392 of 557

ENGINE AND EMISSION CONTROL SYSTEM (TBI FOR G10) 6E1-1
GENERAL DESCRIPTION6E1- 2 . . . . . . . . . . . . . .
AIR AND FUEL DELIVERY SYSTEM 6E1- 4. . . . .
ELECTRONIC CONTROL SYSTEM 6E1- 5. . . . . .
ON-VEHICLE SERVICE6E1- 8 . . . . . . . . . . . . . . . .
General 6E1- 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accelerator Cable Adjustment 6E1- 8. . . . . . . . . .
Idle Speed Inspection 6E1- 8. . . . . . . . . . . . . . . . .
AIR AND FUEL DELIVERY SYSTEM 6E1- 9. . . . .
Fuel Pressure 6E1- 9. . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump 6E1-11. . . . . . . . . . . . . . . . . . . . . . . . . . .
Throttle Body 6E1-12. . . . . . . . . . . . . . . . . . . . . . . .
Fuel injector 6E1-15. . . . . . . . . . . . . . . . . . . . . . . . .
ELECTRONIC CONTROL SYSTEM 6E1-17. . . . . .
ECM 6E1-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAP Sensor 6E1-18. . . . . . . . . . . . . . . . . . . . . . . . .
TP Sensor 6E1-19. . . . . . . . . . . . . . . . . . . . . . . . . . .
IAT Sensor 6E1-20. . . . . . . . . . . . . . . . . . . . . . . . . .
ECT Sensor 6E1-21. . . . . . . . . . . . . . . . . . . . . . . . .
Heated Oxygen Sensor -1 and -2 6E1-23. . . . . . .
Vehicle Speed Sensor 6E1-24. . . . . . . . . . . . . . . . .
Fuel Level Sensor (Gauge) 6E1-24. . . . . . . . . . . . Crankshaft Position Sensor 6E1-25. . . . . . . . . . . .
Main Relay 6E1-25. . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump Relay 6E1-26. . . . . . . . . . . . . . . . . . . . .
Fuel Injector Resistor 6E1-26. . . . . . . . . . . . . . . . .
Fuel Cut Operation 6E1-26. . . . . . . . . . . . . . . . . . .
ISC System 6E1-26. . . . . . . . . . . . . . . . . . . . . . . . . .
ISC Actuator 6E1-27. . . . . . . . . . . . . . . . . . . . . . . . .
CTP Switch 6E1-28. . . . . . . . . . . . . . . . . . . . . . . . . .
ISC Actuator Relay 6E1-29. . . . . . . . . . . . . . . . . . .
EFE Heater Control System 6E1-29. . . . . . . . . . . .
EFE Heater 6E1-29. . . . . . . . . . . . . . . . . . . . . . . . . .
EFE Heater Relay 6E1-30. . . . . . . . . . . . . . . . . . . .
Radiator Fan Control System 6E1-30. . . . . . . . . .
Radiator Fan Control Relay 6E1-31. . . . . . . . . . . .
Radiator Fan 6E1-31. . . . . . . . . . . . . . . . . . . . . . . . .
EMISSION CONTROL SYSTEM 6E1-32. . . . . . . . .
EVAP Control System 6E1-32. . . . . . . . . . . . . . . . .
PCV System 6E1-34. . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS6E1-36 . . . . . . . . . . . . . . . . . . . . . .
TIGHTENING TORQUE
SPECIFICATIONS6E1-36 . . . . . . . . . . . . . . . . . . . .
SECTION 6E1
ENGINE AND EMISSION CONTROL SYSTEM
(TBI FOR G10)
WARNING:
For vehicles equipped with a Supplemental Inflatable Restraint Air Bag System:
Service on or around Air Bag System Components or Wiring must be performed only by an authorized
Suzuki dealer. Please observe all WARNINGS and SERVICE PRECAUTIONS in Section 9J under “On-
Vehicle Service” and the Air Bag System Component and Wiring Location view in Section 9J before
performing service on or around Air Bag System Components or Wiring. Failure to follow WARNINGS
could result in unintended air bag deployment or could render the air bag inoperative. Either of these
two conditions may result in severe injury.
SDM can maintain sufficient voltage to cause a deployment of air bags for up to 15 seconds after igni-
tion switch is turned to “LOCK” position, battery is disconnected or fuse powering SDM is removed.
Work must be started after 15 seconds from the time.
NOTE:
For the descriptions for vehicle without warm up three way catalytic converter (WU TWC), refer to the same
section of the Service Manual mentioned in the FOREWORD of this manual.
CONTENTS