Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-57
DTC P0121 Throttle Position Circuit Range / Performance Problem
WIRING DIAGRAM
Refer to DTC P0120 section.
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 °C, 158 °F or higher
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.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
After engine warmed up.
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.
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? 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. See Fig. 1.
2) Turn ignition switch ON and check TP sen-
sor output voltage when throttle valve is at
idle position and fully opened. See Fig. 3.
Dose voltage vary within specified value linearly
as shown in figure?Substitute a known-good
ECM and recheck.Go to Step 5.
Downloaded from www.Manualslib.com manuals search engine 6-60 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION
[A] Fig. 1 for Step 3 / [B] Fig. 2 for Step 3Step Action Yes No
1Was “Engine Diag. Flow Table” performed? 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 1) Connect scan tool to DLC with ignition
switch OFF. See Fig. 1.
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. 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 “B/Bl”
wires for open and short,
and connections for poor
connection.
If wires and connections
are OK, replace HO2S-1.
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-61
DTC P0133 Heated Oxygen Sensor (HO2S) Circuit Slow Response (Sensor-1)
WIRING DIAGRAM
Refer to DTC P0130 section.
CIRCUIT DESCRIPTION
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” performed? 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.
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-63
INSPECTION
[A] Fig. 1 for Step 2 / [B] Fig. 2 for Step 3Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Check Heater for Operation.
1) Check voltage at terminal E19-7. 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 E19-7. 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
“B/W” and “P/B” wire terminals.
3) If OK, then check heater resistance. See
Fig. 2.
Is it 5 – 6.4 Ω at 20 °C, 68 °F?“P/B” wire open or
shorted to ground or poor
connection at E19-7. If
wire and connection are
OK, substitute a known-
good ECM and recheck.Replace HO2S-1.
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-67
INSPECTION
Fig. 1 for Step 2Step Action Yes No
1Was “Engine Diag. Flow Table” performed? 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 E18-4. 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 or Sensor-2.
1) Disconnect HO2S-2 coupler with ignition
switch OFF.
2) Check for proper connection to HO2S-2 at
“B/W” and “R/Bl” wire terminals.
3) If OK, then check heater for resistance.
Is it 11.7 – 14.3 Ω at 20 °C, 68 °F?“R/Bl” wire open or
shorted to ground or poor
connection at E18-4. If
wire and connection are
OK, substitute a known-
good ECM and recheck.Replace HO2S-2.
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-69
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” performed? 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. See Fig. 1.
2) Warm up engine to normal operating tempera-
ture 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).
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 6E for
details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge. See Fig. 2.
3) Check fuel pressure.
Fuel pressure specification
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 :
210 – 260 kPa, 2.1 – 2.6 kg/cm
2, 29.8 – 37.0 psi.
Is measured value as specified?Go to Step 5. Go to Diag. Flow Table
B-3 Fuel Pressure
Check.
Downloaded from www.Manualslib.com manuals search engine 6-70 ENGINE GENERAL INFORMATION AND DIAGNOSIS
5 Check Fuel Injectors and Circuit.
1) Using sound scope (4) or such, check operating
sound of each injector (5) when engine is run-
ning. 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 coupler) or injector.
2) Turn ignition switch OFF and disconnect a fuel
injector connector.
3) Check for proper connection to fuel injector at
each terminal.
4) If OK, then check injector resistance.
See Fig. 4.
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 6E. 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 injec-
tor closed.
Fuel leakage
Less than 1 drop / min. (1)
Is check result in step 1) and 3) to 7) satisfactory?Go to Step 6. Check injector circuit or
replace fuel injector(s).
6 Check EVAP Canister Purge Valve.
1) Disconnect purge hose (2) 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. 6.
Is vacuum felt?Check EVAP control
system (See Section
6E).Go to Step 7.
7 Check intake manifold absolute pressure sensor for
performance (See step 4) of 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 6E).
Is it in good condition?Go to Step 9. Replace engine coolant
temp. sensor.
9 Check intake air temp. sensor for performance
(See Section 6E).
Is it in good condition?Go to Step 10. Replace intake air temp.
sensor.
10 Check throttle position sensor for performance
(See step 5) 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 Section 6E).
Is it good condition?Substitute a known-
good ECM and recheck.Replace PCV valve. Step Action Yes No
Downloaded from www.Manualslib.com manuals search engine 6-74 ENGINE GENERAL INFORMATION AND DIAGNOSIS
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 by
referring to Section 6F. (See CAUTION)
2) Disconnect all injector connectors. See Fig. 2.
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 6F).
4 Check Fuel Pressure (Refer to Section 6E for details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge. See Fig. 3.
3) Check fuel pressure.
Fuel pressure specification
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 :
210 – 260 kPa, 2.1 – 2.6 kg/cm
2, 29.8 – 37.0 psi.
Is measured value as specified?Go to Step 5. Go to Diag. Flow
Table B-3 fuel pres-
sure check.
5 Check Fuel Injectors and Circuit.
1) sing 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 4.
If no sound or an unusual sound is heard, check
injector circuit (wire or coupler) 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.
4) If OK, then check injector resistance. See Fig. 5.
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 6E. See Fig. 6.
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 6E).
Is it in good condition?Go to Step 7. Replace PCV
valve. Step Action Yes No