2000 SUZUKI SWIFT fuel pressure

6-76 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0171 FUEL SYSTEM TOO LEAN
DTC P0172 FUEL SYSTEM TOO RICH
WIRING DIAGRAM / CIRCUIT DESCRIPTION
1. Injector [a] : Signal to decrease amount of fuel injection [f] : A/F mixture becomes leaner
2. HO2S-1 [b] : Signal to increase amount of fuel injection [g] : Oxygen concentration decreases
3. WU-TWC (Warm up-three way catalytic convec-
tor)[c] : High voltage [h] : Oxygen concentration increases
4. Sensed information [d] : Low voltage
5. ECM [e] : A/F mixture becomes richer
[a]
[b]
[f] [e] [g][d]
[h][c]
1
2 5
1
2
2
3
54
+BECM
C42-9
C42-21
C42-8 C42-31
C42-1
BLU/YEL
BLU/WHT
BLU/RED
BLK/ORN
C42-3
BLK/ORN BLU/ORN
WHT
ORNC42-10C42-13
E111
DTC DETECTING CONDITION POSSIBLE CAUSE
When one of the following conditions occurs while
engine running under closed loop condition.
Air/fuel ratio too lean
(Total fuel trim (short and long terms added) is more
than 30%)
Air/fuel ratio too rich
(Total fuel trim is less than – 30%)
✱2 driving cycle detection logic, continuous monitoring.Vacuum leaks (air drawn in).
Exhaust gas leakage.
Heated oxygen sensor-1 circuit malfunction.
Fuel pressure out of specification.
Fuel injector malfunction (clogged or leakage).
MAP sensor poor performance.
ECT sensor poor performance.
IAT sensor poor performance.
TP sensor poor performance.
EVAP control system malfunction.
PCV valve malfunction.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-77
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Check vehicle and environmental condition for :
–Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 158°F or lower
4) Start engine and drive vehicle under usual driving condition (described in DTC confirmation procedure of
DTC P0136) for 5 min. or longer and until engine is warmed up to normal operating temperature.
5) Keep vehicle speed at 30 – 40 mph, 50 – 60 km/h in 5th gear or “D” range for 5 min. or more.
6) Stop vehicle (do not turn ignition switch OFF).
7) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester, on a level road.
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Is there DTC(s) other than fuel system (DTC
P0171/P0172)?Go to applicable DTC
Diag. Flow Table.Go to Step 3.
3 Check HO2S-1 Output Voltage.
1) Connect scan tool to DLC with ignition
switch OFF.
2) Warm up engine to normal operating tem-
perature 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.
Does HO2S-1 output voltage deflect between
below 0.3 V and over 0.6 V repeatedly?Go to Step 4. Go to DTC P0130 Diag.
Flow Table (HO2S-1 cir-
cuit check).
4 Check 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. See Fig. 2. With fuel
pump operating and engine at stop :
270 – 310 kPa, 2.7 – 3.1 kg/cm
2, 38.4 –
44.0 psi.
At specified idle speed :
270 – 310 kPa, 2.7 – 3.1 kg/cm
2, 38.4 –
44.0 psi.
Is measured value as specified?Go to Step 5. Go to Diag. Flow Table B-
3 Fuel Pressure Check.

6-78 ENGINE GENERAL INFORMATION AND DIAGNOSIS
5 Check Fuel Injectors and Circuit.
1) Using sound scope (1) or such, check oper-
ating sound of each injector (2) when
engine is running. Cycle of operating sound
should vary according to engine speed. See
Fig. 3. If no sound or an unusual sound is
heard, check injector circuit (wire or cou-
pler) or injector.
2) Turn ignition switch OFF and disconnect a
fuel injector connector.
3) Check for proper connection to fuel injector
at each terminal. See Fig. 4.
4) If OK, then check injector resistance.
Injector Resistance : 11.3 – 13.8 ohm at
20°C (68°F)
5) Carry out steps 1) and 3) on each injector.
6) Check each injector for injected fuel volume
(1) referring to Section 6E1. See Fig. 5.
Injected Fuel Volume : 43 – 47 cc/15 sec
1.45/1.51 – 1.58/1.65 US/Imp.oz/15 sec)
7) Check each injector for fuel leakage after
injector closed. Fuel Leakage : Less than 1
drop/min.
Is check result in step 1) and 3) to 7) satisfac-
tory?Go to Step 6. Check injector circuit or
replace fuel injector(s).
6 Check EVAP Canister Purge Valve.
1) Disconnect purge hose from EVAP canister
purge valve.
2) Place finger against the end of EVAP canis-
ter purge valve.
3) Check that vacuum is not felt there when
engine is cool and running at idle. See Fig.
6.
Is vacuum felt?Check EVAP control sys-
tem (See Section 6E1).Go to Step 7.
7 Check Intake manifold absolute pressure sen-
sor for performance (See DTC P0105 (No.11)
Diag. Flow Table).
Is it in good condition?Go to Step 8. Repair or replace.
8 Check Engine Coolant Temp. Sensor for perfor-
mance (See Section 6E1).
Is it in good condition?Go to Step 9. Replace engine coolant
temp. sensor.
9 Check Intake Air Temp. Sensor for perfor-
mance (See Section 6E1).
Is it in good condition?Go to Step 10. Replace intake air temp.
sensor.
10 Check Throttle Position Sensor for performance
(See Step 4 of DTC P0121 Diag. Flow Table).
Is it in good condition?Go to Step 11. Replace throttle position
sensor.
11 Check PCV Valve for valve clogging (See Sec-
tion 6E1).
Is it good condition?Substitute a known-good
ECM and recheck.Replace PCV valve. Step Action Yes No

6-82 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Check vehicle and environmental condition for :
–Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 158°F or lower
–Engine coolant temp. : – 10 – 110°C, 14 – 230°F
4) Start engine and keep it at idle for 2 min. or more.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
6) If DTC is not detected at idle, consult usual driving based on information obtained in “Customer complaint
analysis” and “Freeze frame data check”.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
Engine under other than high revolution condition
Not on rough road
Engine speed changing rate (Below specified value)
Manifold absolute pressure changing rate (Below
specified value)
Throttle opening changing rate (Below specified
value)
Misfire rate per 200 or 1000 engine revolutions (how
much and how often crankshaft revolution speed
changes) is higher than specified valueEngine overheating
Vacuum leaks (air inhaling) from air intake system
Ignition system malfunction (spark plug(s), high-
tension cord(s), ignition coil assembly)
Fuel pressure out of specification
Fuel injector malfunction (clogged or leakage)
Engine compression out of specification
Valve lash (clearance) out of specification
Manifold absolute pressure sensor malfunction
Engine coolant temp. sensor malfunction
PCV valve malfunction
EVAP control system malfunction
EGR system malfunction
NOTE:
Among different types of random misfire, if misfire occurs at cylinders 1 and 4 or cylinders 3 and 2
simultaneously, it may not possible to reconfirm DTC by using the following DTC confirmation proce-
dure. When diagnosing the trouble of DTC P0300 (Random misfire detected) of the engine which is
apparently misfiring, even if DTC P0300 cannot be reconfirmed by using the following DTC confirma-
tion procedure, proceed to the following Diag. Flow Table.
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester.
CAUTION:
For iridium spark plugs, do not adjust air gap or clean.
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE
DIAG. FLOW
TABLE”.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-83
2 Is there DTC other than Fuel system (DTC P0171/
P0172) and misfire (DTC P0300-P0304)?Go to applicable DTC
Diag. Flow Table.Go to Step 3.
3 Check Ignition System.
1) Remove spark plugs and check them for;
Air gap : 1.0 – 1.1 mm (0.040 – 0.043 in.) See Fig. 1.
Carbon deposits/Insulator damage/Plug type
If abnormality is found, adjust, clean or replace.
2) Disconnect all injector connectors.
3) Connect spark plugs to high tension cords and then
ground spark plugs.
4) Crank engine and check that each spark plug sparks.
Are above check results satisfactory?Go to Step 4. Check ignition sys-
tem parts (Refer to
Section 6F1)
4 Check Fuel Pressure (Refer to Section 6E1 for details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge. See Fig. 2.
3) Check fuel pressure.
With fuel pump operating and engine at stop : 270 –
310 kPa, 2.7 – 3.1 kg/cm
2, 38.4 – 44.0 psi.
At specified idle speed : 270 – 310 kPa, 2.7 – 3.1 kg/
cm
2, 38.4 – 44.0 psi.
Is measured value as specified?Go to Step 5. Go to Diag. Flow
Table B-3 fuel
pressure check.
5 Check Fuel Injectors and Circuit.
1) Using sound scope (1) or such, check operating
sound of each injector (2) when engine is running.
Cycle of operating sound should very according to
engine speed. See Fig 3.
If no sound or an unusual sound is heard, check
injector circuit (wire or connector) or injector.
2) Turn ignition switch OFF and disconnect a fuel injec-
tor connector.
3) Check for proper connection to fuel injector at each
terminal. See Fig. 4.
4) If OK, then check injector resistance.
Injector Resistance : 11.3 – 13.8 ohm at 20°C (68°F)
5) Carry out steps 1) and 3) on each injector.
6) Check each injector for injected fuel volume referring
to Section 6E1. See Fig. 5.
Injected Fuel Volume : 43 – 47 cc/15 sec (1.45/1.51 –
1.58/1.65 US/Imp. oz/15 sec)
7) Check each injector for fuel leakage after injector
closed.
Fuel Leakage : Less than 1 drop/min.
Is check result in step 1) and 3) to 7) satisfactory?Go to Step 6. Check injector cir-
cuit or replace fuel
injector(s).
6 Check PCV Valve for clogging (See Section 6E1).
Is it in good condition?Go to Step 7. Replace PCV
valve. Step Action Yes No

6-84 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Fig. 1 for Step 3
Fig. 2 for Step 47 Check EVAP Canister Purge Valve for Closing.
1) Disconnect purge hose from EVAP canister purge
valve.
2) Place finger against the end of EVAP canister purge
valve.
3) Check that vacuum is not felt there, when engine is
cool and running at idle. See Fig. 6.
Is vacuum felt?Check EVAP control
system (See Section
6E1).Go to Step 8.
8 Check MAP Sensor for performance (See DTC P0105
Diag. Flow Table).
Is it in good condition?Go to Step 9. Repair or replace.
9 Check ECT Sensor for performance (See Section 6E1).
Is it in good condition?Go to Step 10. Replace engine
coolant temp. sen-
sor.
10 Check Parts or System which can cause engine rough
idle or poor performance.
Engine compression (See Section 6A1).
Valve lash (See Section 6A1).
Valve timing (Timing belt installation. See Section
6A1).
Are they in good condition?Check wire harness
and connection of
ECM ground, ignition
system and fuel injec-
tor for intermittent
open and short.Repair or replace. Step Action Yes No
1. Fuel pressure gauge & 3 way joint
2. Fuel feed hose
1
2
1

6-94 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0400 EXHAUST GAS RECIRCULATION FLOW MALFUNCTION
WIRING DIAGRAM / CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
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. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 122°F or lower
2) Start engine and warm it up to normal operating temperature (70 – 110°C, 158 – 230°F) and run it at idle for
5 min.
3) Increase vehicle speed to 50 – 55 mph, 80 – 88 km/h in 5th gear or in “D” range.
4) Hold throttle valve at that opening position for 2 min. or longer.
5) Increase engine speed to 4000 r/min. in 3rd gear or in “2” range.
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) till
engine speed reaches 1500 r/min.
1. EGR valve [A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
+BECM
C42-18
C42-29
C42-28 C42-17
C42-1
GRY
GRN/ORN
WHT/RED
C42-3 BRN/YEL
BLK/ORN
BLK/ORN BLK/RED1
3
1 2
4
6 5
+BECM
C41-2
C41-9
C41-17 C41-8
C42-1
GRN
GRN/ORN
WHT/RED
C42-3 BRN/YEL
BLK/ORN
BLK/ORN BLK/RED1
3
1 2
4
6 5
[A][B]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
DTC DETECTING CONDITION POSSIBLE CAUSE
While running at specified vehicle speed after engine warm-up
During deceleration (engine speed high with closed throttle position
ON) in which fuel cut is involved, difference in intake manifold abso-
lute pressure between when EGR valve is opened at specified value
and when it is closed is larger or smaller than specified value.
✱2 driving cycle detection logic, monitoring once/1 drivingEGR valve or its circuit
EGR passage
ECM
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester, on a level road.

6-98 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC CONFIRMATION PROCEDURE
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. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 158°F or lower
–Engine coolant temp. : 70 – 110°C, 158 – 230°F
2) Start engine and drive vehicle at 35 – 45 mph, 55 – 65 km/h for 8 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 COMPLETE” is still being displayed, continue test driving.
3) Decrease vehicle speed at 30 – 40 mph, 50 – 60 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
Confirmation Flow Table”.
TEST RESULT CONFIRMATION FLOW TABLE
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent 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.
Step Action Yes No
1 Check 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.
2 Set scan tool to “READINESS TESTS” mode
and check if testing has been completed.
Is test completed?No DTC is detected (con-
firmation test is com-
pleted).Repeat DTC confirmation
procedure.