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DTC P0120 (DTC No.13) Throttle Position Circuit Malfunction
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. DTC DETECTING CONDITION POSSIBLE CAUSE
Signal voltage high
Signal voltage low“B/Bl” circuit open
“Lg” circuit open or shorted to ground
“B/Bl” circuit open or shorted to power or ground
TP sensor malfunction
ECM malfunction
NOTE:
When DTC P0105 (No.11), P0110 (No.18), P0115 (No.19), P0120 (No.13) and/or P0460 are indicated
together, it is possible that “B/Bl” or “Lg/R” circuit is open.
When this DTC and P1700 are stored together, also clear DTC stored in TCM after completion of
repair.
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INSPECTION
[A] Fig. 1 for Step 2 / [B] Fig. 2 for Step 3 / [C] Fig. 3 for Step 4Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Check TP Sensor and Its Circuit.
1) Connect scan tool to DLC with ignition
switch OFF and then turn ignition switch ON.
See Fig. 1.
2) Check throttle valve opening percentage dis-
played on scan tool.
Is it displayed 0% or 100%?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.
3 Check Wire Harness.
1) Disconnect connector from TP sensor with
ignition switch OFF.
2) Check for proper connection to TP sensor at
“Lg/R”, “Lg” and “B/Bl” wire terminal.
3) If OK, then with ignition switch ON, check
voltage at each of “Lg/R” and “Lg” wire ter-
minals and body ground. See Fig. 2.
Is voltage about 4 – 6 V at each terminal?Go to Step 4.“Lg/R” wire open, “Lg/R”
wire shorted to ground cir-
cuit or power circuit or
“B/Bl” wire, “Lg” wire open
or shorted to ground cir-
cuit or poor E19-22 or
E19-16 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
4 Check TP Sensor.
1) Check resistance between terminals of TP
sensor. See Fig. 3.
TP sensor resistance
Between 1 and 3 : 4.0 – 6.0 k
Ω
ΩΩ Ω
Between 2 and 3 : Varying according to
throttle valve opening (0.02 – 6.0 k
Ω
ΩΩ Ω)
Are measured values within specifications?“B/Bl” wire open or poor
E19-10 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.Replace TP sensor.
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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.
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[A] Fig. 1 for Step 3 / [B] Fig. 2 for Step 4 / [C] Fig. 3 for Step 3 and 4
Fig. 4 for Step 54 Check TP Sensor and its Circuit.
1) Turn ignition switch ON.
2) Check voltage at terminal E19-16 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 E19-16 for
poor connection.
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.
TP sensor resistance
Between 1 and 2 : 4.0 – 6.0 k
Ω
ΩΩ Ω
Between 1 and 3 : 0.02 – 6.0 k
Ω
ΩΩ Ω, varying
according to throttle valve opening.
Are measured values as specified?High resistance in “Lg/R”,
“Lg” or “B/Bl” circuit.
If wire and connection are
OK, substitute a known-
good ECM and recheck.Replace TP sensor. Step Action Yes No
[A] : When using SUZUKI scan tool.
[B] : When not using SUZUKI scan tool.
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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 ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-73
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.
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine
Diag. Flow Table”.
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.
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DTC P0400 Exhaust Gas Recirculation Flow Malfunction
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
1. EGR valve
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 absolute
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.
Downloaded from www.Manualslib.com manuals search engine 6-86 ENGINE GENERAL INFORMATION AND DIAGNOSIS
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.
7) Stop vehicle (don’t turn ignition switch OFF) and confirm test results according to following “Test Result Con-
firmation Flow Table.”
Test Result Confirmation Flow Table
INSPECTION
Step Action Yes No
1 Check DTC in “DTC” mode and pending DTC in
“ON BOARD TEST”.
Is DTC or pending DTC displayed?Proceed to applicable
DTC 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.
(Confirmation test is com-
pleted)Repeat DTC confirmation
procedure.
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 1) Turn ignition switch ON.
2) Does EGR stepper motor operation for 0.6
second after ignition switch OFF?Go to Step 3. Go to Step 6.
3 With ignition switch at OFF, check voltage
between E19-28, 17, 29, 18 terminals of ECM
and body ground. See Fig. 2.
Is voltage about 0 V?Go to Step 4. Go to Step 8.