2000 SUZUKI SWIFT throttle

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

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.

Main
fuseMain relay
Idle speed
control relay
To TP sensor
Idle speed control actuator
6-86 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0505 IDLE CONTROL SYSTEM MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
DTC will set when A, B or C condition is met.
A: Throttle opening change is small as compared with
electrically live time.
B: Throttle valve opening is not within its target range
with CTP switch ON.
C: Drive voltage exists though ECM (PCM) is not
outputting ISC drive command.
Malajusted accelerater cable

Poor movement of throttle valve

Closed throttle position switch malfunction

Idle speed control actuator malfunction

Idle speed control relay malfunction

“Gr / B”, “Gr / Y”, “Gr”, “Gr / R”, “Gr / G”, “Lg” or “B/Bl”
circuit open or short

Throttle position sensor malfunction

ECM (PCM) malfunction
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Start cold engine.
4) Run it idle for 5 min.
5) Select “DTC” mode on scan tool and check DTC.
NOTE:
If engine speed changes up and down when engine speed is increased by opening throttle valve more
than half but not changing its opening, it is possible that closed throttle position switch is malfunction-
ing.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-87
Fig. 1 for Step 3 Fig. 2 for Step 3 Fig. 3 for Step 3
1. ISCA relay
2. Relay box
DTC P0505
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check Idle Control System.
1) Connect SUZUKI scan tool to DLC with ignition
switch OFF, set parking brake and block drive
wheels.
2) Warm up engine to normal operating
temperature.
3) Clear DTC and select “MISC TEST” mode on
SUZUKI scan tool.
Is it possible to control (increase and reduce)
engine idle speed by using SUZUKI scan tool?Check TP sensor (Go to
DTC P0121 Flow Table)
If TP sensor is OK,
intermittent trouble or
faulty ECM (PCM).
Check for intermittent
referring to “Intermittent
and Poor Connection”
in Section 0A.Go to Step 3.
3Check ISC Relay.
1) Ignition switch OFF and remove ISC relay
(“ISCA”).
2) Check for proper connection to ISC relay at
terminals 3 and 4.
3) Check resistance between each two terminals.
Between terminals 1 and 2: Infinity
Between terminals 3 and 4: 100 – 120 Ω
4) Check that there is continuity between
terminals 1 and 2 when battery is connected to
terminals 3 and 4.
Is ISC relay in good condition?Go to Step 4.Replace ISC relay.
4Check Idle Speed Control Actuator.
1) Check ISC actuator operation by referring to
ISC ACTUATOR INSPECTION in Section 6.
Is it good condition?Check “Gr / B”, “Gr / Y”,
“Gr” and “Gr / R” circuit
for open and short.
If wires and connections
are OK, substitute a
known-good ECM
(PCM) and recheck.Replace throttle lower
body with ISC actuator.

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).

1. Fuel pump
2. Fuel filter
3. Throttle body
4. Fuel injector
5. Fuel pressure regulator6. Special tool
(Fuel pressure gauge &
3-way joint)
7. Fuel feed line
8. Fuel return line
6-100 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
TABLE B-3 FUEL PRESSURE CHECK
INSPECTION
STEPACTIONYESNO
1Check Fuel Pressure (Refer to Section 6E1 for details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge.
3) Check fuel pressure by repeating ignition switch
ON and OFF. See Fig. 1.
Is fuel pressure then 160 – 210 kPa (1.6 – 2.1 kg / cm
2,
22.7 – 29.9 psi)?
Go to Step 2.Go to Step 4.
2Is 90 kPa (0.9 kg / cm2, 12.8 psi) or higher fuel
pressure retained for 1 minute after fuel pump is
stopped at Step 1?Normal fuel pressure.Go to Step 3.
31) Start engine and warm it up to normal operating
temperature.
2) Keep it running at specified idle speed.
Is fuel pressure then within 90 – 140 kPa
(0.9 – 1.4 kg / cm
2, 12.8 – 20.0 psi)?
Normal fuel pressure.
Clogged vacuum
passage for fuel
pressure regulator
or

Faulty fuel pressure
regulator.
4Is there fuel leakage from fuel feed line hose, pipe or
their joint?Fuel leakage from
hose, pipe or joint.Go to Step 10.
5Was fuel pressure higher than specification in Step 1?Go to Step 6.Go to Step 7.
61) Disconnect fuel return hose from throttle body and
connect new return hose to it.
2) Insert the other end of new return hose into
approved gasoline container.
3) Operate fuel pump.
Is specified fuel pressure obtained then?Restricted fuel return
hose or pipe.Faulty fuel pressure
regulator.
7Was no fuel pressure supplied in Step 1?Go to Step 8.Go to Step 9.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-101
Fig. 1 for Step 1
1. Fuel pressure gauge & 3way joint
STEPACTIONYESNO
8With fuel pump operated and fuel return hose
blocked by pinching it, is fuel pressure applied?Faulty fuel pressure
regulator.Shortage of fuel or fuel
pump or its circuit
defective (refer to B-2
FUEL PUMP ANDITS
CIRCUIT CHECK).
91) Operate fuel pump.
2) With fuel return hose blocked by pinching it, check
fuel pressure.
Is it 450 kPa (4.5 kg / cm
2, 63.9 psi) or more?
Faulty fuel pressure
regulator.
Clogged fuel filter,

Restricted fuel feed
hose or pipe,

Faulty fuel pump or

Fuel leakage from
hose connection in
fuel tank.
101) Disconnect fuel return hose from throttle body and
connect new return hose to it.
2) Insert the other end of new return hose into
approved gasoline container.
3) Check again if specified pressure is retained.
While doing so, does fuel come out of return hose?Faulty fuel pressure
regulator.
Fuel leakage from
injector,

Fuel leakage from
between injector
and throttle body,

Faulty fuel pump
(faulty check valve
in fuel pump) or

Fuel leakage from
fuel pressure
regulator
diaphragm.

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