2000 SUZUKI SWIFT stop start

6-46 ENGINE GENERAL INFORMATION AND DIAGNOSIS
TABLE A-1 MALFUNCTION INDICATOR LAMP CIRCUIT CHECK - LAMP DOES
NOT COME “ON” AT IGNITION SWITCH ON (BUT ENGINE AT STOP)
WIRING DIAGRAM
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, ECM causes the main relay to turn ON (close the contact point). Then,
ECM being supplied with the main power, turns ON the malfunction indicator lamp (MIL). When the engine
starts to run and no malfunction is detected in the system, MIL goes OFF but if a malfunction was or is detected,
MIL remains ON even when the engine is running.
INSPECTION
1. BATT fuse 3. IG METER fuse 5. Monitor connector 7. To ignition switch
2. Main fuse box 4. To battery 6. MIL
[A] : Case of TYPE A is shown
(See NOTE)[B] : Case of TYPE B is shown
(See NOTE)
1
12V5V
ECM
23
+BB
DA
C
BLK/WHT
BRN/WHT
BLK/RED
BLK/RED
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
BLK
DN
TS
GNDMON
PPL/WHTC42-27 [A]
C42-16 [A]
PNK/BLUC42-28 [A]
7 4
G02-1 [A]IG1
5
6IG1
WHT/GRN
BLK/WHT
G02-6 [A]
C41-5 C41-6 C41-10 C41-11 [B]C41-14 [B]
C41-15 [B]
C41-8 [B]
G02-9 [B]
PPL/WHT
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
Step Action Yes No
1 MIL Power Supply Check
1) Turn ignition switch ON.
Do other indicator/warning lights in combination
meter comes ON?Go to Step 2.“IG METER” fuse blown,
main fuse blown, ignition
switch malfunction, “BLK/
WHT” circuit between “IG
METER” fuse and combi-
nation meter or poor cou-
pler connection at
combination meter.
2 ECM Power and Ground Circuit Check
Does engine start?Go to Step 3. Go to TABLE A-5 ECM
POWER AND GROUND
CIRCUIT CHECK.
If engine is not cranked,
go to DIAGNOSIS in Sec-
tion 6G.

6-70 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0135 (DTC NO.14) HEATED OXYGEN SENSOR (HO2S) HEATER CIRCUIT
MALFUNCTION (SENSOR-1)
WIRING DIAGRAM / CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON, start engine and keep it at idle for 1 min.
3) Start vehicle and depress accelerator pedal fully for 5 sec. or longer.
4) Stop vehicle.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
ECM
BLK/WHT
RED/BLU
C42-7 IG1
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
DTC DETECTING CONDITION POSSIBLE CAUSE
DTC will set when one of the following conditions is met.
Low voltage at terminal C42-7 when engine is running
at high load.
High voltage at terminal C42-7 when engine is running
under condition other than above.
✱2 driving cycle detection logic, Continuous monitoring.HO2S-1 heater circuit open or shorted to ground
ECM malfunction
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.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-71
INSPECTION
Fig. 1 for Step 2
Fig. 2 for Step 3Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check Heater for operation.
1) Check voltage at terminal C42-7. See Fig.
1.
2) Warm up engine to normal operating tem-
perature.
3) Stop engine.
4) Turn ignition switch ON and Check voltage
at terminal C42-7. See Fig. 1. Voltage
should be over 10 V.
5) Start engine, run it at idle and check voltage
at the same terminal. Voltage should be
below 1.9 V.
Are check results are specified?Intermittent trouble Check
for intermittent referring to
“Intermittent and Poor
Connection” in Section
0A.Go to Step 3.
3 Check Heater of Sensor-1.
1) Disconnect HO2S-1 coupler with ignition
switch OFF.
2) Check for proper connection to HO2S-1 at
“BLK/WHT” and “RED/BLU” wire terminals.
3) If OK, then check heater resistance. See
Fig. 2.
Is it 5.0 – 6.4 Ω at 20°C, 68°F?“RED/BLU” wire open or
shorted to ground or poor
connection at C42-7. If
wire and connection are
OK, substitute a known-
good ECM and recheck.Replace HO2S-1.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-75
INSPECTION
Fig. 1 for Step 2Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check HO2S-2 Heater and Its Circuit.
1) Warm up engine to normal operating tem-
perature.
2) Stop engine.
3) Turn ignition switch ON and check voltage
at terminal C41-4 See Fig. 1. Voltage
should be over 10 V.
4) Start engine, run it at idle and check voltage
at the same terminal after 1 min. from
engine start.
Voltage should be below 1.9 V.
Are check result as specified?Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Go to Step 3.
3 Check Heater of Sensor-2.
1) Disconnect HO2S-2 coupler with ignition
switch OFF.
2) Check for proper connection to HO2S-2 at
“BLK/WHT” and “PNK/BLU” wire terminals.
3) If OK, then check heater resistance.
Is it 12.0 – 14.3 Ω at 20°C, 68°F?“PNK/BLU” wire open or
shorted to ground or poor
connection at C41-4. If
wire and connection are
OK, substitute a known-
good ECM and recheck.Replace HO2S-2.

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.

6-86 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0325 (DTC NO.17) KNOCK SENSOR CIRCUIT MALFUNCTION
WIRING DIAGRAM / CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select “DTC” mode on scan tool and check DTC.
INSPECTION
[A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
ECM
5V
RED
E11
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
C42-12 [A]
C42-25 [B]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
DTC DETECTING CONDITION POSSIBLE CAUSE
Knock sensor voltage is 3.91 V or more
or
Knock sensor voltage is 1.23 V or less“RED” circuit open or shorted to ground
Knock sensor malfunction
ECM malfunction
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check Knock Sensor Signal.
1) With engine running, check voltage from
C42-12 terminal of ECM connector to body
ground. See Fig. 1.
Is voltage about 1.23 – 3.91 V?Knock sensor and its cir-
cuit are in good condition.
Intermittent trouble or
faulty ECM.
Recheck, referring to
Intermittent Trouble in
Section 0A.Go to Step 3.
3 Check Knock Sensor Output.
1) Stop engine.
2) With ignition switch at OFF position, discon-
nect knock sensor connector.
3) With ignition switch at ON position, check
voltage from “RED” terminal of knock sen-
sor connector to body ground. See Fig. 2.
Is it 4 – 5 V?Faulty knock sensor.
Substitute a known-good
knock sensor and
recheck.“RED” wire open, shorted
to ground circuit or poor
C42-12 (Case of TYPE A.
See NOTE) or 42-25
(Case of TYPE B. See
NOTE) connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.

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.

6-108 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P1450 BAROMETRIC PRESSURE SENSOR LOW/HIGH INPUT
DTC P1451 BAROMETRIC PRESSURE SENSOR PERFORMANCE PROBLEM
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Barometric pressure sensor is installed in ECM.
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Turn ignition switch ON for 2 sec., crank engine for 2 sec. and run it at idle for 1 min.
4) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
DTC P1450 :
Substitute a known-good ECM and recheck.
DTC P1451 :
DTC DETECTING CONDITION POSSIBLE CAUSE
DTC P1450 :
Barometric pressure : Sensor voltage is 4.7 V or higher, or
1.6 V or lowerECM (barometric pressure sensor) malfunc-
tion
DTC P1451 :
Vehicle stopped
Engine cranking
Difference between barometric pressure and intake mani-
fold absolute pressure is 26 kPa, 200 mmHg or more
Difference between intake manifold absolute pressure at
engine start and the pressure after engine start is 1.3 kPa,
10 mmHg or less.
✱2 driving cycle detection logic, monitoring once/1 driving.Manifold absolute pressure sensor and its
circuit malfunction
ECM (barometric pressure sensor) malfunc-
tion
NOTE:
Note that atmospheric pressure varies depending on weather conditions as well as altitude.
Take that into consideration when performing these check.
Step Action Yes No
1 Check Barometric Pressure Valve.
1) Connect scan tool to DLC with ignition
switch OFF.
2) Turn ignition switch ON and select “DATA
LIST” mode on scan tool.
3) Check manifold absolute pressure. See Fig.
1.
Is it barometric pressure (approx. 100 kPa, 760
mmHg) at sea level?Substitute a known-good
ECM and recheck.Go to Step 2.