2000 SUZUKI SWIFT SF310 Service Workshop Manual

Main
fuseMain relay
Idle speed
control relay
To TP sensor
Idle speed control actuator
6-86 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0505 IDLE CONTROL SYSTEM MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
DTC will set when A, B or C condition is met.
A: Throttle opening change is small as compared with
electrically live time.
B: Throttle valve opening is not within its target range
with CTP switch ON.
C: Drive voltage exists though ECM (PCM) is not
outputting ISC drive command.
Malajusted accelerater cable

Poor movement of throttle valve

Closed throttle position switch malfunction

Idle speed control actuator malfunction

Idle speed control relay malfunction

“Gr / B”, “Gr / Y”, “Gr”, “Gr / R”, “Gr / G”, “Lg” or “B/Bl”
circuit open or short

Throttle position sensor malfunction

ECM (PCM) malfunction
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Start cold engine.
4) Run it idle for 5 min.
5) Select “DTC” mode on scan tool and check DTC.
NOTE:
If engine speed changes up and down when engine speed is increased by opening throttle valve more
than half but not changing its opening, it is possible that closed throttle position switch is malfunction-
ing.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-87
Fig. 1 for Step 3 Fig. 2 for Step 3 Fig. 3 for Step 3
1. ISCA relay
2. Relay box
DTC P0505
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check Idle Control System.
1) Connect SUZUKI scan tool to DLC with ignition
switch OFF, set parking brake and block drive
wheels.
2) Warm up engine to normal operating
temperature.
3) Clear DTC and select “MISC TEST” mode on
SUZUKI scan tool.
Is it possible to control (increase and reduce)
engine idle speed by using SUZUKI scan tool?Check TP sensor (Go to
DTC P0121 Flow Table)
If TP sensor is OK,
intermittent trouble or
faulty ECM (PCM).
Check for intermittent
referring to “Intermittent
and Poor Connection”
in Section 0A.Go to Step 3.
3Check ISC Relay.
1) Ignition switch OFF and remove ISC relay
(“ISCA”).
2) Check for proper connection to ISC relay at
terminals 3 and 4.
3) Check resistance between each two terminals.
Between terminals 1 and 2: Infinity
Between terminals 3 and 4: 100 – 120 Ω
4) Check that there is continuity between
terminals 1 and 2 when battery is connected to
terminals 3 and 4.
Is ISC relay in good condition?Go to Step 4.Replace ISC relay.
4Check Idle Speed Control Actuator.
1) Check ISC actuator operation by referring to
ISC ACTUATOR INSPECTION in Section 6.
Is it good condition?Check “Gr / B”, “Gr / Y”,
“Gr” and “Gr / R” circuit
for open and short.
If wires and connections
are OK, substitute a
known-good ECM
(PCM) and recheck.Replace throttle lower
body with ISC actuator.

6-88 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Fig. 1 for Step 2 Fig. 2 for Step 3
Lever is apart
from plunger
Lever contacts
with plunger Condition “A”:
throttle lever is in contact
with ISC actuator plunger
Condition “B”:
Throttle lever is apart
from plunger
DTC P0510 CLOSED THROTTLE POSITION (CTP) SWITCH MALFUNCTION
CIRCUIT DESCRIPTION – Refer to DTC P0505 section.
DTC DETECTING CONDITIONPOSSIBLE CAUSE

Even when vehicle is started from stop and
accelerated to specified vehicle speed, CTP switch
does not turn from ON to OFF (or from OFF to ON).
2 driving cycle detection logic, continuous
monitoring
“Lg”, “Gr / G” or “B/Bl” circuit open or short

CTP switch malfunction

ECM (PCM) malfunction
NOTE:
When DTC P0105, P0120 and / or P0510 are indicated together, it is possible that “Lg” circuit is open.
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF, clear DTC with ignition switch ON and start engine.
2) Increase vehicle speed to 20 mph, 32 km / h and then stop vehicle.
3) Repeat above step 2) 15 times.
4) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check CTP Switch Operation.
1) Connect SUZUKI scan tool to DLC with ignition
switch OFF.
2) Turn ignition switch ON.
Does CTP switch operate properly under following
conditions respectively?
Condition “A”: ON displayed on scan tool
Condition “B”: OFF displayed on scan tool
Is test result satisfactory?Intermittent trouble.
Check for intermittent
referring to
“Intermittent and
Poor Connection in
Section 0A.Go to Step 3.
3Check CTP switch.
1) Arrange 3 new 1.5 V batteries in series (4.5 V in
total).
2) Connect these batteries to CTP switch terminals
“4” and “5”.
3) Under following each condition, check voltage
between CTP switch terminals “6” and “5”.
Condition “A”: 0 – 1 V
Condition “B”: 3.5 – 5.5 V
Is measured voltage as specified?Check “Lg”, “Gr / G”
and “B/Bl” wires and
connections for open
or short.
If wires and
connections are OK,
substitute a known-
good ECM (PCM) and
recheck.Replace ISC motor
set (throttle lower
body with ISC
actuator).

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-89
DTC P0601 INTERNAL CONTROL MODULE MEMORY CHECK SUM ERROR
DTC DETECTING CONDITIONPOSSIBLE CAUSE
DTC P0601: Data write error (or check sum error)
when written into ECM (PCM)
2 driving cycle detection logic, continuous monitoring.ECM (PCM)
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON and then turn ignition switch OFF.
3) Start engine and run it at idle if possible.
4) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
Substitute a known-good ECM (PCM) and recheck.

Main
fuseMain relay
EFE heater EFE heater relay
6-90 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P1250 EARLY FUEL EVAPORATION (EFE) HEATER CIRCUIT
MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

Voltage low at terminal C01-12 during engine
warming up
or

Voltage high at terminal C01-12 after engine
warming up
2 driving cycle detection logic, continuous
monitoring
“Y/R”, “W” or “W/B” circuit open or short

EFE heater relay malfunction

EFE heater malfunction

ECM (PCM) malfunction
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: –10C, 14F or higher
–Intake air temp: 70C, 158F or lower
4) Start cool engine and warm it up to normal operating temperature.
5) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-91
1. Relay box
2.“PTC”
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check EFE Heater and Its Circuit.
Check for voltage at terminal C01-12 of ECM (PCM)
connector connected, under following each
condition.
During engine warming up (Coolant temp.:
Below 80C, 176F, Engine speed: Over 750 r / min):
Over 1.0 V
After warming up: Below 1.0 V
Is each voltage as specified?Intermittent trouble.
Check for intermittent
referring to
“Intermittent and Poor
Connection” in
Section 0A.Go to Step 3.
3Check EFE Heater Relay.
1) Turn OFF ignition switch and remove EFE heater
relay (“PTC”). See Fig. 2.
2) Check for proper connection to relay at terminal
3 and 4. See Fig. 3.
3) Check resistance between each two terminals.
Between terminals 1 and 2: Infinity
Between terminals 3 and 4: 100 – 120 Ω
4) Check that there is continuity between terminals
1 and 2 when battery is connected to terminals
3 and 4. See Fig. 4.
Is EFE heater relay in good condition?Go to Step 4.Replace EFE heater
relay.
4Check EFE Heater and Its Circuit.
1) Turn ignition switch OFF and disconnect ECM
(PCM) connectors.
2) Check for proper connection to ECM (PCM) at
terminals C02-25 and C01-12.
3) If OK, then measure resistance between terminal
C01-12 and ground.
Is it 0.5 – 30 Ω at 20C (68F)?“W”, “Y/R” or “W/B”
circuit open or short.
If wire and
connections are OK,
substitute a known-
good ECM (PCM) and
recheck.“W/B” circuit open or
short.
If wire and
connections are OK,
replace EFE heater.
Fig 1. for Step 4 Fig. 2 for Step 3 Fig. 3 for Step 3
Fig. 4 for Step 3

6-92 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Fig. 1 for Step 1
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 (PCM).
DTC DETECTING CONDITION
POSSIBLE CAUSE
DTC P1450:

Barometric pressure: 136 kPa 1025 mmHg or higher, or
33 kPa 250 mmHg or lower
ECM (PCM) (barometric pressure sensor)
malfunction
DTC P1451:

Vehicle stopped.

Engine cranking.

Difference between barometric pressure and intake
manifold absolute pressure is 26 kPa, 200 mmHg or more.
2 driving cycle detection logic, monitoring once / 1 driving.
Manifold absolute pressure sensor and its
circuit malfunction

ECM (PCM) (barometric pressure sensor)
malfunction
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 (PCM) and recheck.
DTC P1451:
NOTE:
Note that atmospheric pressure varies depending on weather conditions as well as altitude.
Take that into consideration when performing these check.
STEP
ACTIONYESNO
11) 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 (PCM) and
recheck.Check intake manifold
pressure sensor and its
circuit.
Go to P0105 DIAG.
FLOW TABLE.

Main
fuse
M / T vehicle
Ignition
switch
(starter
switch)Starter
A / T vehicle
Main
fuse
Ignition
switch
(starter
switch)Transmission
range sensor (switch)
StarterPCM
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-93
DTC P1500 ENGINE STARTER SIGNAL CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

High voltage at terminal C01-16 for 3 min. after engine
start.

Low voltage at terminal C01-16 during starting engine.
2 driving cycle detection logic, continuous monitoring.
“B/Y” circuit open

ECM (PCM) malfunction
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON, crank engine and run it at idle for 3 min.
3) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check for voltage at terminal C01-16 of ECM
(PCM) connector connected, under following
condition.
While engine cranking : 6 – 10 V
After starting engine : 0 V
Is voltage as specified?Poor C01-16
connection or
intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection”
in Section 0A.
If wire and connections
are OK, substitute a
known-good ECM (PCM)
and recheck.“B/Y” circuit open.