SUZUKI SWIFT 2000 1.G RG413 Service Workshop Manual

6-62 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Fig. 2 for Step 3
Fig. 3 for Step 4

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-63
DTC P0121 THROTTLE POSITION CIRCUIT RANGE/PERFORMANCE PROB-
LEM
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, 158°F or lower
–Engine coolant temp. : 70 – 110°C, 158 – 230°F
2) Warm up engine to normal operating temperature.
3) Increase vehicle speed to 30 – 40 mph, 50 – 60 km/h in 3rd gear or “D” range and hold throttle valve at that
opening position for 1 min.
4) Stop vehicle.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
[A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
C42-10
C42-22
5V5V
ECM
GRY/RED
GRY/BLU
ORN
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
C42-16 [B]C41-3 [A]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
DTC DETECTING CONDITION POSSIBLE CAUSE
DTC will set when the following conditions are detected.
After engine warmed up.
While vehicle running at specified engine speed.
No change in intake manifold pressure (constant throttle opening)
Difference between actual throttle opening (detected from TP sensor)
and opening calculated by ECM (Obtained on the basis of engine
speed and intake manifold pressure) in larger than specified value.
✱2 driving cycle detection logic, continuous monitoringTP sensor malfunction
High resistance in the circuit
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, on a level road.

6-64 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION
Fig. 1 for Step 3Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Is SUZUKI scan tool available? Go to Step 3. Go to Step 4.
3 Check TP Sensor and its Circuit.
1) Turn ignition switch OFF and connect
SUZUKI scan tool to DLC.
2) Turn ignition switch ON and check TP sen-
sor output voltage when throttle valve is at
idle position and fully opened. See Fig. 1
and 3.
Dose voltage vary within specified value linearly
as shown in figure?If voltmeter was used,
check terminal C41-3 (For
TYPE A, See NOTE) or
C42-16 (For TYPE B, See
NOTE) for poor connec-
tion.
If OK, substitute a known-
good ECM and recheck.Go to Step 5.
4 Check TP Sensor and Its Circuit.
1) Turn ignition switch ON.
2) Check voltage at terminal C41-3 (For TYPE
A, See NOTE) or C42-16 (For TYPE B, See
NOTE) of ECM connector connected, when
throttle valve is at idle position and fully
opened. See Fig. 2 and 3.
Dose voltage vary within specified value linearly
as shown in figure?If voltmeter was used,
check terminal C41-3 (For
TYPE A, See NOTE) or
C42-16 (For TYPE B, See
NOTE) for poor connec-
tion.
If OK, substitute a known-
good ECM and recheck.Go to Step 5.
5 Check TP Sensor.
1) Turn ignition switch OFF.
2) Disconnect TP sensor connector.
3) Check for proper connection to TP sensor
at each terminal.
4) If OK, then measure resistance between
terminals and check if each measured value
is as specified below.
See Fig. 4.
Between 1 and 2 : 4.0 – 6.0 kΩ
Between 1 and 3 : 0.02 – 6.0 kΩ, varying
according to throttle valve opening.
Are measured values as specified?High resistance in “GRY/
RED”, “GRY/BLU” or
“ORN” circuit.
If wire and connection are
OK, substitute a known-
good ECM and recheck.Replace TP sensor.
[A] : When using SUZUKI scan tool:
[ A]

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-65
Fig. 2 for Step 4
Fig. 3 for Step 3 and 4
Fig. 4 for Step 5
[A] : When not using SUZUKI scan tool:
[a] : Case of TYPE A is shown (See NOTE)
[b] : Case of TYPE B is shown (See NOTE)

6-66 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0130 (DTC NO.14) HEATED OXYGEN SENSOR (HO2S) CIRCUIT MAL-
FUNCTION (SENSOR-1)
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, 158°F or lower
2) Warm up engine to normal operating temperature.
3) Drive vehicle at 30 – 40 mph, 50 – 60 km/h for 2 min.
4) Stop vehicle and run engine at idle for 2 min.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
ECM
WHT
ORNC42-10 C42-13
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
DTC DETECTING CONDITION POSSIBLE CAUSE
When running at idle speed after engine warmed up and
running at specified vehicle speed, HO2S-1 output volt-
age does not go below 0.3 V or over 0.6 V.
✱2 driving cycle detection logic, Monitoring once/1 driving.Heated oxygen sensor-1 malfunction
“WHT” or “ORN” circuit open (poor connection)
or short
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 6-67
INSPECTION
Fig. 1 for Step 3
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 Is there DTC(s) other than HO2S-1 (DTC
P0130)?Go to applicable DTC
Diag. Flow Table.Go to Step 3.
3 Check HO2S-1 signal.
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 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 “WHT” and “ORN”
wires for open and short,
and connections for poor
connection.
If wires and connections
are OK, replace HO2S-1.

6-68 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0133 HEATED OXYGEN SENSOR (HO2S) CIRCUIT SLOW RESPONSE
(SENSOR-1)
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Refer to DTC P0130 section.
Fig. 1
DTC CONFIRMATION PROCEDURE
Refer to DTC P0130 section.
INSPECTION
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
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 HO2S-1 (DTC
P0133)?Go to applicable DTC
Diag. Flow Table.Replace HO2S-1.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-69
DTC P0134 HEATED OXYGEN SENSOR (HO2S) CIRCUIT NO ACTIVITY
DETECTED (SENSOR-1)
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Refer to DTC P0130 section.
DTC CONFIRMATION PROCEDURE
Refer to DTC P0131 section.
INSPECTION
Fig. 1 for Step 3DTC DETECTING CONDITION POSSIBLE CAUSE
Engine warmed up.
While running under other than high load and high engine speed
conditions or at specified idle speed (engine is in closed loop con-
dition), HO2S-1 output voltage is high or low continuously.
✱2 driving cycle detection logic, Continuous monitoring.“WHT” or “ORN” circuit open or short
Heated oxygen sensor malfunction
Fuel system malfunction
Exhaust gas leakage
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) and HO2S-1 (DTC
P0134)?Go to applicable DTC
Diag. Flow Table.Go to Step 3.
3 Check HO2S-1 and Its Circuit.
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
0.3V and over 0.6V repeatedly?Go to DTC P0171 and
P0172 Diag. Flow Table
(Fuel System Check).Check “WHT” and “ORN”
wires for open and short,
and connections for poor
connection. If wires and
connections are OK,
replace HO2S-1.

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.