ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-9
PRECAUTION IN DIAGNOSING TROUBLE
Don’t disconnect couplers from ECM (PCM), battery cable from
battery, ECM (PCM) ground wire harness from engine or main
fuse before confirming diagnostic information (DTC, freeze frame
data, etc.) stored in ECM (PCM) memory. Such disconnection will
erase memorized information in ECM (PCM) memory.
Diagnostic information stored in ECM (PCM) memory can be
cleared as well as checked by using SUZUKI scan tool (Tech-1)
or generic scan tool. Before using scan tool, read its Operator’s
(Instruction) Manual carefully to have good understanding as to
what functions are available and how to use it.
Priorities for diagnosing troubles.
If two or more DTCs are stored, proceed to the flow table of the
DTC which has detected earliest in the order and follow the
instruction in that table.
If no instructions are given, troubleshoot diagnostic trouble codes
according to the following priorities.
1. Diagnostic trouble codes (DTCs) other than DTC P0171 /
P0172 (Fuel system too lean / too rich) and DTC P0300 /
P0301 / P0302 / P0303 (Misfire detected)
2. DTC P0171 / P0172 (Fuel system too lean / too rich)
3. DTC P0300 / P0301 / P0302 / P0303 (Misfire detected)
Be sure to read “Precautions for Electrical Circuit Service” in Sec-
tion 0A before inspection and observe what is written there.
ECM (PCM) Replacement
When substituting a known-good ECM (PCM), check for following
conditions. Neglecting this check may cause damage to a known-
good ECM (PCM).
–Resistance value of all relays, actuators is as specified respec-
tively.
–MAP sensor and TP sensor are in good condition and none of
power circuits of these sensors is shorted to ground.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-15
DIAGNOSTIC TROUBLE CODE (DTC) TABLE
DTC
NO.DETECTING ITEMDETECTING CONDITION
(DTC will set when detecting:)MIL
P0105Manifold absolute pressure
circuit malfunction
Low pressure-high vacuum-low voltage
(or MAP sensor circuit shorted to ground)
High pressure-low vacuum-high voltage
(or MAP sensor circuit open)
1 driving cycle
P0110Intake air temp. circuit
malfunctionIntake air temp. circuit low input
Intake air temp. circuit high input1 driving cycle
P0115Engine coolant temp. circuit
malfunctionEngine coolant temp. circuit low input
Engine coolant temp. circuit high input1 driving cycle
P0120Throttle position circuit
malfunctionThrottle position circuit low input
Throttle position circuit high input1 driving cycle
P0121Throttle position circuit
performance problemPoor performance of TP sensor2 driving cycles
P0130HO2S circuit malfunction
(Sensor-1)
Min. output voltage of HO2S-higher than
specification
Max. output voltage of HO2S-lower than
specification
2 driving cycles
P0133HO2S circuit slow response
(Sensor-1)Response time of HO2S-1 output voltage
between rich and lean is longer than
specification.
2 driving cycles
P0135HO2S heater circuit
malfunction (Sensor-1)Terminal voltage is lower than specification
at heater OFF or it is higher at heater ON.2 driving cycles
P0136HO2S circuit malfunction
(Sensor-2)Max. voltage of HO2S-2 is lower than
specification or its min. voltage is higher than
specification
2 driving cycles
P0141HO2S heater circuit
malfunction (Sensor-2)Terminal voltage is lower than specification
at heater OFF or it is higher at heater ON.
(or heater circuit or short)
2 driving cycles
P0171Fuel system too lean
Short term fuel trim or total fuel trim (short
and long terms added) is larger than
specification for specified time or longer.
(fuel trim toward rich side is large.)
2 driving cycles
P0172Fuel system too rich
Short term fuel trim or total fuel trim (short
and long term added) is smaller than
specification for specified time or longer.
(fuel trim toward lean side is large.)
2 driving cycles
P0300
P0301
P0302
Random misfire detected
Cylinder 1 misfire detected
Cylinder 2 misfire detected
Misfire of such level as to cause damage to
three way catalystMIL flashing
during misfire
detection
P0302
P0303
Cylinder 2 misfire detected
Cylinder 3 misfire detectedMisfire of such level as to deteriorate emission
but not to cause damage to three way catalyst2 driving cycles
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-25
ConditionPossible CauseReferring Item
Engine hesitates
(Momentary lack of
response as
accelerator is
depressed.
Can occur at all
vehicle speeds.
Usually most severe
when first trying to
make vehicle move,
as from a stop sign.)Ignition system out of order
Spark plug faulty or plug gap out of adjustment
Leaky high-tension cord
Fuel system out of order
Fuel pressure out of specification
Engine and emission control system out of
order
Poor performance of TP sensor, ECT sensor or
MAP sensor
Faulty fuel injector
Faulty ECM (PCM)
Engine overheating
Low compression
Spark plugs in Section 6F
High-tension cords in Section 6F
Diagnostic Flow Table B-3
Trouble diagnosis in Section 6
TP sensor, ECT sensor or MAP
sensor in Section 6E1
Diagnostic Flow Table B-1
Refer to “Overheating” section
Previously outlined
Surge
(Engine power
variation under
steady throttle or
cruise.
Feels like vehicle
speeds up and down
with no change in
accelerator pedal.)Ignition system out of order
Leaky or loosely connected high-tension cord
Faulty spark plug (excess carbon deposits,
improper gap, and burned electrodes, etc.)
Fuel system out of order
Variable fuel pressure
Kinky or damaged fuel hose and lines
Faulty fuel pump (clogged fuel filter)
Engine and emission control system out of
order
Poor performance of MAP sensor
Faulty fuel injector
Faulty ECM (PCM)
High-tension cords in Section 6F
Spark plugs in Section 6F
Diagnostic Flow Table B-3
MAP sensor in Section 6E1
Diagnostic Flow Table B-1
Excessive
detonation
(Engine makes
continuously
sharp metallic
knocks that change
with throttle opening.
Sounds like pop corn
popping.)Engine overheating
Ignition system out of order
Faulty spark plug
Loose connection of high-tension cord
Fuel system out of order
Clogged fuel filter (faulty fuel pump) or fuel lines
Air inhaling from intake manifold or throttle body
gasket
Engine and emission control system out of
order
Poor performance of ECT sensor or MAP sensor
Faulty fuel injector
Faulty ECM (PCM)
Excessive combustion chamber depositsRefer to “Overheating” section
Spark plugs in Section 6F
High-tension cords in Section 6F
Diagnostic Flow Table B-1 or B-2
Trouble diagnosis in Section 6
ECT sensor or MAP sensor in
Section 6E1
Diagnostic Flow Table B-1
Piston and cylinder head cleaning
in Section 6A
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-55
Fig. 1 for Step 3 Fig. 2 for Step 3
Normal
Fig. 1
HO2S-1
Output
voltage1 cycle time
Response time
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Is there DTC(s) other than HO2S-1
(DTC P0130)?Go to applicable DTC
Diag. Flow Table.Go to Step 3.
31) 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 and 2.
Does HO2S-1 output voltage deflect between
0.3 V and over 0.6 V repeatedly?Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection”
in Section 0A.Check “R” and “G”
wires for open and
short, and connections
for poor connection.
If wires and connections
are OK, replace
HO2S-1.
DTC P0133 HEATED OXYGEN SENSOR (HO2S) CIRCUIT SLOW RESPONSE
(SENSOR-1)
WIRING DIAGRAM / CIRCUIT DESCRIPTION – Refer to DTC P0130 section.
DTC DETECTING CONDITION
POSSIBLE CAUSE
When running at specified idle speed after engine
warmed up and running at specified vehicle speed,
response time (time to change from lean to rich or
from rich to lean) of HO2S-1 output voltage is about
1 sec. at minimum or average time of 1 cycle is 5 sec.
at minimum. See. Fig. 1
2 driving cycle detection logic, Monitoring once / 1
driving.Heated oxygen sensor-1 malfunction
6-88 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Fig. 1 for Step 2 Fig. 2 for Step 3
Lever is apart
from plunger
Lever contacts
with plunger Condition “A”:
throttle lever is in contact
with ISC actuator plunger
Condition “B”:
Throttle lever is apart
from plunger
DTC P0510 CLOSED THROTTLE POSITION (CTP) SWITCH MALFUNCTION
CIRCUIT DESCRIPTION – Refer to DTC P0505 section.
DTC DETECTING CONDITIONPOSSIBLE CAUSE
Even when vehicle is started from stop and
accelerated to specified vehicle speed, CTP switch
does not turn from ON to OFF (or from OFF to ON).
2 driving cycle detection logic, continuous
monitoring“Lg”, “Gr / G” or “B/Bl” circuit open or short
CTP switch malfunction
ECM (PCM) malfunction
NOTE:
When DTC P0105, P0120 and / or P0510 are indicated together, it is possible that “Lg” circuit is open.
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF, clear DTC with ignition switch ON and start engine.
2) Increase vehicle speed to 20 mph, 32 km / h and then stop vehicle.
3) Repeat above step 2) 15 times.
4) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check CTP Switch Operation.
1) Connect SUZUKI scan tool to DLC with ignition
switch OFF.
2) Turn ignition switch ON.
Does CTP switch operate properly under following
conditions respectively?
Condition “A”: ON displayed on scan tool
Condition “B”: OFF displayed on scan tool
Is test result satisfactory?Intermittent trouble.
Check for intermittent
referring to
“Intermittent and
Poor Connection in
Section 0A.Go to Step 3.
3Check CTP switch.
1) Arrange 3 new 1.5 V batteries in series (4.5 V in
total).
2) Connect these batteries to CTP switch terminals
“4” and “5”.
3) Under following each condition, check voltage
between CTP switch terminals “6” and “5”.
Condition “A”: 0 – 1 V
Condition “B”: 3.5 – 5.5 V
Is measured voltage as specified?Check “Lg”, “Gr / G”
and “B/Bl” wires and
connections for open
or short.
If wires and
connections are OK,
substitute a known-
good ECM (PCM) and
recheck.Replace ISC motor
set (throttle lower
body with ISC
actuator).
“IG
COIL
METER”
Main
fuseIgnition
switch
Main
relayTo other circuits
Injector resistor Fuel injector
6-96 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
TABLE B-1 FUEL INJECTOR CIRCUIT CHECK
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Injector Circuit Check
1) Check injector circuit for short.
Is fuel injected from injector at ignition switch ON?“Y/B” wire shorted to
ground or faulty
injector.
If wire and injector is
as specified
respectively and then
substitute known-
good ECM (PCM) and
recheck.Go to Step 3.
3Injector Check
1) Check injector for fuel Injection referring to FUEL
INJECTOR ON-VEHICLE INSPECTION in
Section 6E1.
Is fuel injected from injector at engine cranking?Go to Step 4.Go to Step 5.
4Injector Leakage Check
1) Check injector for leaks referring to FUEL
INJECTOR ON-VEHICLE INSPECTION in
Section 6E1.
Is it in good condition?Injector and its circuit
are in good condition.Faulty fuel injector.
5Check Injector for Operating Sound.
1) Using sound scope, check injector for operating
sound at engine cranking.
Is it detected?Proceed to DIAG.
FLOW TABLE B-2 and
B-3.Go to Step 6.
6-1
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-1
GENERAL INFORMATION6-1- 3 . . . . . . . . . . . . . .
ENGINE DIAGNOSIS6-1- 6 . . . . . . . . . . . . . . . . . . .
General Description 6-1- 6. . . . . . . . . . . . . . . . . . .
On-Board Diagnostic System 6-1- 6. . . . . . . . . .
Precaution in Diagnosing Trouble 6-1- 9. . . . . . .
Engine Diagnostic Flow Table 6-1-10. . . . . . . . . .
Customer Problem Inspection From 6-1-12. . .
Malfunction Indicator Lamp Check 6-1-13. . . .
Diagnostic Trouble Code Check 6-1-13. . . . . .
Diagnostic Trouble Code Clearance 6-1-14. . .
Diagnostic Trouble Code Table 6-1-15. . . . . . .
Fail-safe Table 6-1-18. . . . . . . . . . . . . . . . . . . . .
Visual Inspection 6-1-19. . . . . . . . . . . . . . . . . . .
Engine Basic Inspection 6-1-20. . . . . . . . . . . . .
Engine Diagnosis Table 6-1-22. . . . . . . . . . . . .
Scan Tool Data 6-1-29. . . . . . . . . . . . . . . . . . . . . . .
Inspection of ECM (PCM) and Its
Circuits 6-1-33. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage Check 6-1-33. . . . . . . . . . . . . . . . . . . . .
Resistance Check 6-1-37. . . . . . . . . . . . . . . . . .
Component Location 6-1-38. . . . . . . . . . . . . . . . . .
Table A-1 MIL Circuit Check
(Lamp does not come on) 6-1-39. . . . . . . . . . . . Table A-2 MIL Circuit Check
(Lamp remains ON) 6-1-40. . . . . . . . . . . . . . . . . .
Table A-3 ECM (PCM) Power and
Ground Circuit Check 6-1-41. . . . . . . . . . . . . . . .
DTC P0105 MAP Circuit Malfunction 6-1-43. . . .
DTC P0110 IAT Circuit Malfunction 6-1-46. . . . .
DTC P0115 ECT Circuit Malfunction 6-1-48. . . .
DTC P0120 Throttle Position Circuit
Malfunction 6-1-50. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0121 Throttle Position Circuit
Range / Performance Problem 6-1-52. . . . . . . . .
DTC P0130 HO2S Circuit Malfunction
(Sensor-1) 6-1-54. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0133 HO2S Circuit Slow
Response (Sensor-1) 6-1-56. . . . . . . . . . . . . . . .
DTC P0134 HO2S Circuit No Activity
Detected 6-1-57. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0135 HO2S Heater Circuit
Malfunction (Sensor-1) 6-1-58. . . . . . . . . . . . . . .
DTC P0136 HO2S Circuit Malfunction
(Sensor-2) 6-1-60. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0141 HO2S Heater Circuit
Malfunction (Sensor-2) 6-1-63. . . . . . . . . . . . . . .
DTC P0171 Fuel System Too Lean 6-1-65. . . . .
DTC P0172 Fuel System Too Rich 6-1-65. . . . . .
SECTION 6-1
ENGINE GENERAL INFORMATION
AND DIAGNOSIS
(SFI FOR G13)
WARNING:
For vehicles equipped with Supplemental Restraint (Air Bag) System:
Service on and around the air bag system components or wiring must be performed only by an autho-
rized SUZUKI dealer. Refer to “Air Bag System Components and Wiring Location View” under “Gener-
al Description” in air bag system section in order to confirm whether you are performing service on
or near the air bag system components or wiring. Please observe all WARNINGS and “Service Precau-
tions” under “On-Vehicle Service” in air bag system section before performing service on or around
the air bag system components or wiring. Failure to follow WARNINGS could result in unintentional
activation of the system or could render the system inoperative. Either of these two conditions may
result in severe injury.
Technical service work must be started at least 90 seconds after the ignition switch is turned to the
“LOCK” position and the negative cable is disconnected from the battery. Otherwise, the system may
be activated by reserve energy in the Sensing and Diagnostic Module (SDM).
CONTENTS
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-9
PRECAUTION IN DIAGNOSING TROUBLE
Don’t disconnect couplers from ECM (PCM), battery cable from
battery, ECM (PCM) ground wire harness from engine or main
fuse before confirming diagnostic information (DTC, freeze frame
data, etc.) stored in ECM (PCM) memory. Such disconnection will
erase memorized information in ECM (PCM) memory.
Diagnostic information stored in ECM (PCM) memory can be
cleared as well as checked by using SUZUKI scan tool (Tech-1)
or generic scan tool. Before using scan tool, read its Operator’s
(Instruction) Manual carefully to have good understanding as to
what functions are available and how to use it.
Priorities for diagnosing troubles
If two or more DTCs are stored, proceed to the flow table of the
DTC which was detected earliest in the order and follow the
instruction in that table.
If no instructions are given, troubleshoot DTCs according to the
following priorities.
1. Diagnostic trouble codes (DTCs) other than DTC
P0171 / P0172 (Fuel system too lean / too rich), DTC
P0300 / P0301 / P0302 / P0303 / P0304 (Misfire detected) and
DTC P0400 (EGR flow malfunction)
2. DTC P0171 / P0172 (Fuel system too lean / too rich) and DTC
P0400 (EGR flow malfunction)
3. DTC P0300 / P0301 / P0302 / P0303 / P0304 (Misfire detected)
Be sure to read “Precautions for Electrical Circuit Service” in Sec-
tion 0A before inspection and observe what is written there.
ECM (PCM) Replacement
When substituting a known-good ECM (PCM), check for following
conditions. Neglecting this check may cause damage to a known-
good ECM (PCM).
–Resistance value of all relays, actuators is as specified respec-
tively.
–MAP sensor and TP sensor are in good condition and none of
power circuits of these sensors is shorted to ground.