2000 SUZUKI SWIFT SF310 Service Workshop Manual

To other sensors IAT sensor
6-46 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0110 INTAKE AIR TEMP. (IAT) CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

Low intake air temperature (High voltage-High resistance)
or

High intake air temperature (Low voltage-Low resistance)
“Gr” circuit open or shorted to power

“G” circuit open

IAT sensor malfunction

ECM (PCM) malfunction
NOTE:

When DTC P0105, P0110, P0115 and P0120 are indicated together, it is possible that “G” circuit is open.

Before inspecting, be sure to check that ambient temperature is higher than –40C (–40F).
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select “DTC” mode no scan tool and check DTC.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-47
Fig. 1 for Step 2 Fig. 2 for Step 3 Fig. 3 for Step 4
Scan tool
DLC
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check IAT Sensor and Its Circuit.
1) Connect scan tool to DLC with ignition switch
OFF.
2) Turn ignition switch ON.
3) Check intake air temp. displayed on scan tool.
See Fig. 1.
Is –40C (–40F) or 119C (246F) indicated?Go to Step 3.Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection”
in Section 0A.
3Check Wire Harness.
1) Disconnect IAT sensor connector with ignition
switch OFF.
2) Check for proper connection to IAT sensor at
“Gr” and “G” wire terminals.
3) If OK, then with ignition switch ON, is voltage
applied to “Gr” wire terminal about 4 – 6 V? See
Fig. 2.Go to Step 5.“Gr” wire open or
shorted to power, or
poor C01-14
connection.
If wire and connection
are OK, substitute a
known-good ECM
(PCM) and recheck.
4Does scan tool indicate –40C (–40F) at Step 2.Go to Step 6.Go to Step 5.
5Check Wire Harness.
1) Check intake air temp. displayed on scan tool
with ignition switch ON.
Is –40C (–40F) indicated?Replace IAT sensor.“Gr” wire shorted to
ground.
If wire is OK, substitute
a known-good ECM
(PCM) and recheck.
6Check Wire Harness.
1) Using service wire, connect IAT sensor
connector terminals.
2) Check intake air temp. displayed on scan tool
with ignition switch ON. See Fig. 3.
Is 119C (246F) indicated?Replace IAT sensor.“Gr” wire open or poor
C01-9 connection.
If wire and connection
are OK, substitute a
known-good ECM
(PCM) and recheck.

ECT sensor
To combination
(ECT) meterTo other sensors
6-48 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0115 ENGINE COOLANT TEMPERATURE (ECT) CIRCUIT
MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

Low engine coolant temperature (High voltage-High resistance)
or

High engine coolant temperature (Low voltage-Low resistance)
“Gr / W” circuit open or shorted to power

“G” circuit open

ECT sensor malfunction

ECM (PCM) malfunction
NOTE:
Before inspecting, be sure to check that coolant temp. meter in combination meter indicates normal oper-
ating temperature (Engine is not overheating).
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.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-49
Fig. 1 for Step 2 Fig. 2 for Step 3 Fig. 3 for Step 4
Scan tool
DLC
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check ECT Sensor and Its Circuit.
1) Connect scan tool with ignition switch OFF.
2) Turn ignition switch ON.
3) Check engine coolant temp. displayed on scan
tool. See Fig. 1.
Is –40C (–40F) or 119C (246F) indicated?Go to Step 3.Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection”
in Section 0 A.
3Check Wire Harness.
1) Disconnect ECT sensor connector.
2) Check engine coolant temp. displayed on scan
tool.
Is –40C (–40F) indicated?Replace ECT sensor.“Gr / W” wire shorted to
ground.
If wire is OK, substitute
a known-good ECM
(PCM) and recheck.
4Does scan tool indicate –40C (–40F) at Step 2.Go to Step 6.Go to Step 5.
5Check Wire Harness.
1) Disconnect ECT sensor connector with
ignition switch OFF.
2) Check for proper connection to ECT sensor at
“G” and “Gr / W” wire terminals.
3) If OK, then with ignition switch ON, is voltage
applied to “G” wire terminal about 4 – 6 V?
See Fig. 2.Go to Step 4.“Gr / W” wire open or
shorted to power, or
poor C01-7 connection.
If wire and connection
are OK, substitute a
known-good ECM
(PCM) and recheck.
6Check Wire Harness.
1) Using service wire, connect ECT sensor
connector terminals. See Fig. 3.
2) Turn ignition switch ON and check engine
coolant temp. displayed on scan tool.
Is 119C (246F) indicated?Replace ECT sensor.“G” wire open or
poor C01-9 connection.
If wire and connection
are OK, substitute a
known-good ECM
(PCM) and recheck.

To other sensors Throttle
position
sensorTo other sensors
6-50 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0120 THROTTLE POSITION CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

Signal voltage high
or

Signal voltage low
“G” circuit open

“Lg / W” circuit open or shorted to ground

“Lg” circuit open or shorted to power or ground

TP sensor malfunction

ECM (PCM) malfunction
NOTE:

When DTC P0105, P0110, P0115 and / or P0120 are indicated together, it is possible that “G” circuit is
open.

When DTC P0105, P0120 and / or P0510 are indicated together it is possible that “Lg” circuit is open.
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.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-51
Fig. 1 for Step 2 Fig. 2 for Step 3 Fig. 3 for Step 4
Scan tool
“Lg” “Lg/W”
“3”“4”
“1”
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE”
performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check TP Sensor and Its Circuit.
1) Connect scan tool to DLC with ignition
switch OFF and then turn ignition switch
ON.
2) Check throttle valve opening percentage
displayed on scan tool. See Fig. 1.
Is it displayed 2% or less?
3) Check throttle valve opening percentage
displayed on scan tool while opening
throttle valve from idle position to full open
position. See Fig. 1.
Is it displayed 96% or higher?Go to Step 3.Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0 A.
3Check Wire Harness.
1) Disconnect connector from TP sensor
with ignition switch OFF.
2) Check for proper connection to TP sensor
at “Lg”, “Lg/W” and “G” wire terminal.
3) If OK, then with ignition switch ON, check
voltage at each of “Lg” and “Lg / W” wire
terminals. See Fig. 2.
Is voltage about 4 – 6 V at each terminal?Go to Step 4.“Lg” wire open, “Lg”
wire shorted to ground
circuit or power circuit or
“G” wire, “Lg / W” wire
open or shorted to ground
circuit or poor C01-1 or
C01-6 connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.
4Check TP Sensor.
1) Check resistance between terminals of
TP sensor. See Fig. 3.
Between 1 and 4: 2.87 – 5.33 kΩ
Between 1 and 3: 100 Ω – 20 kΩ, varying
according to throttle valve opening.
Are measured values within specifications?“G” wire open or poor
C01–9 connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace TP sensor.

To other sensors Throttle
position
sensorTo other sensors
6-52 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0121 THROTTLE POSITION CIRCUIT RANGE / PERFORMANCE
PROBLEM
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

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 (PCM) (Obtained on the basis of
engine speed and intake manifold pressure) in larger than specified
value.
2 driving cycle detection logic, continuous monitoring
TP sensor malfunction

High resistance in the circuit

ECM (PCM) malfunction
DTC CONFIRMATION PROCEDURE
WARNING:

When performing a road test, select a place where there is no traffic or possibility of a traffic accident
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.
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.: –10C, 14F or higher
–Intake air temp.: 70C, 158F or lower
–Engine coolant temp.: 70 – 11 0C, 158 – 230F
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.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-53
Fig. 1 for Step 2 Fig. 2 for Step 2
Fig. 3 for Step 3
Closed
(condition “A”)Fully open
Throttle Opening
Condition “A”
Clearance between throttle lever and
throttle stop screw is less than 0.35 mm
(0.014 in.).
clearance
“1”“3”“4”
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE
DIAG. FLOW
TABLE”.
2Check 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 sensor output
voltage when throttle valve is at idle position and fully
opened. See Fig. 1 and 2.
Dose voltage vary within specified value linearly as shown in
figure?If voltmeter was
used, check
terminal C01-6 for
poor connection.
If OK, substitute a
known-good ECM
(PCM) and
recheck.Go to Step 3.
3Check 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. 3.
Between 1 and 4: 2.87 – 5.33 kΩ
Between 1 and 3: 100 Ω – 20 kΩ, varying according to
throttle valve opening.
Are measured values as specified?High resistance in
“Lg”, “Lg / W” or
“G” circuit.
If wire and
connection are
OK, substitute a
known-good ECM
(PCM) and
recheck.Replace TP
sensor.