2000 SUZUKI SWIFT ECM

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-81
Fig. 1 for Step 2 Fig. 2 for Step 3
1. Radiator fan relay
2. Relay box
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check Radiator Cooling Fan Relay and Its Circuit.
1) Turn ignition switch ON.
2) Check for voltage at terminal C02-20 of ECM
(PCM) connector connected, under following
condition. See Fig. 1.
When engine coolant temp. is lower than
96C, 205F and A / C switch turns OFF:
10 – 14 V
Is voltage as specified?Intermittent trouble or
faulty ECM (PCM).
Check for intermittent
referring to “Intermittent
and Poor Connection”
in Section 0A.Go to Step 3.
3Check Radiator Fan Control Relay.
1) Turn ignition switch OFF and remove radiator
fan relay.
2) Check for proper connection to the relay at
“B/W” and “Bl” wire terminals.
3) If OK, then measure resistance between
terminals a and b. See Fig. 2.
Is it 100 – 120 Ω?“B/W” or “Bl” circuit
open or short.
If wires and connections
are OK, substitute a
known-good ECM (PCM)
and recheck.Replace radiator fan
relay.

6-82 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Vehicle speed
sensor in
combination meterC03-2
C03-2
DTC P0500 VEHICLE SPEED SENSOR (VSS) MALFUNCTION (M / T)
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

VSS signal not inputted while vehicle running in “D”
range or during fuel cut at deceleration.
2 driving cycle detection logic, continuous monitoring
“B/Bl” circuit open

“Y/G” circuit open or short

VSS malfunction

ECM malfunction

Speedometer cable 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.
1) Clear DTC and warm up engine to normal operating temperature.
2) Increase vehicle speed to 50 mph, 80 km / h in 3rd gear or “2” range while observing vehicle speed displayed
on scan tool.
3) Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) for 4 sec.
or more.
4) Check pending DTC and DTC.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-83
Fig. 1 for Step 3 Fig. 2 for Step 4
C03-2
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Does speedometer indicate vehicle speed?Go to Step 3.Speedometer cable
disconnected or
broken.
3Check VSS and Its Circuit.
1) Disconnect ECM connector with ignition
switch OFF.
2) Check for proper connection to ECM at
terminal C03-2.
3) If OK, then connect ohmmeter between
terminal C03-2 of ECM connector and body
ground. See Fig. 1.
4) Hoist front end of vehicle and lock front right
tire.
5) Turn front left tire slowly.
Does ohmmeter indicator deflect between
0 and ∞ a few times while tire is turned one
revolution?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection”
in Section 0A.Go to Step 4.
4Check VSS.
1) Remove combination meter.
2) Connect ohmmeter between “VSS” terminal
(No.10) and “GND” (No.4) terminal of
combination meter and turn cable joint of
speedometer with a screwdriver. Ohmmeter
indicator should move back and forth between
0 (zero) and ∞ (infinity) 4 times while cable joint
is turned one full revolution. See Fig. 2.
Is it in good condition?“Y / G” or “B / Bl” wire
open or short, or poor
connector connection.Replace VSS.

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.