check engine SUZUKI SWIFT 2000 1.G SF310 Service Owner's Guide

6-34 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
1. ECM (PCM)
2. ECM (PCM) couplers
(Viewed from harness side)
1. ECM (PCM)
2. Couplers
3. Body ground
4. Service wire
16
C03 C02 C01
1
2
1 2 3
4 5 6
7 8 9 10 11 1 2
3 4 5 6 7 8 1 2
3 4 5 6 7 8 9 10 11 12 13
12
13 14 15
16 17 18 19
20 21 22 9 10
11 12 13 14 15 14 15
16 17 18 19 20 21 22 23 24
25 26
INSPECTION OF ECM (PCM) AND ITS
CIRCUITS
ECM (PCM) and its circuits can be checked at ECM (PCM) wiring
couplers by measuring voltage and resistance.
CAUTION:
ECM (PCM) cannot be checked by itself. It is strictly prohib-
ited to connect voltmeter or ohmmeter to ECM (PCM) with
coupler disconnected from it.
Voltage Check
1) Remove ECM (PCM) (1) from body referring to Section 6E.
2) Check voltage at each terminal of couplers (2) connected.
NOTE:
As each terminal voltage is affected by the battery voltage,
confirm that it is 11 V or more when ignition switch is ON.

6-38 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
1 2
1. ECM (PCM)
coupler disconnected
2. Ohmmeter
RESISTANCE CHECK
1) Disconnect ECM (PCM) couplers from ECM (PCM) with ignition
switch OFF.
CAUTION:
Never touch terminals of ECM (PCM) itself or connect
voltmeter or ohmmeter.
2) Check resistance between each terminal of couplers discon-
nected.
CAUTION:

Be sure to connect ohmmeter probe from wire harness
side of coupler.

Be sure to turn OFF ignition switch for this check.

Resistance in table below represents that when parts
temperature is 20C (68F).
TERMINALSCIRCUITSTANDARD RESISTANCE
C01-8 to C03-20H02S-1 heater11.7 – 14.3 Ω
C02-19 to C03-20H02S-2 heater11.7 – 14.3 Ω
C02-12 to C02-2 / 15Fuel injector2.4 – 3.6 Ω
C02-7 to C02-2 / 15EVAP canister purge valve30 – 34 Ω
C02-21 to C03-20Fuel pump relay100 – 120 Ω
C02-16 to C02-2 / 15ISC actuator relay100 – 120 Ω
C02-25 to C02-2 / 15EFE heater relay100 – 120 Ω
C02-8 to Body groundShift solenoid-B8 – 20 Ω
C02-9 to Body groundShift solenoid-A8 – 20 Ω
C02-20 to C02-2 / 15Radiator fan control relay100 – 120 Ω
C02-22 to C02-14Main relay100 – 120 Ω
C02-1 to Body groundGroundContinuity
C02-13 to Body groundGroundContinuity
C02-26 to Body groundGroundContinuity

6-40 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
“IG COIL METER”Main relay
Ignition switch
In fuseMalfunction indicator lamp in combination meter
TABLE A-1 MALFUNCTION INDICATOR LAMP CIRCUIT CHECK – LAMP DOES
NOT COME “ON” AT IGNITION SWITCH ON (BUT ENGINE AT STOP)
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, ECM (PCM) causes the main relay to turn ON (close the contact point).
Then, ECM (PCM) being supplied with the main power, turns ON the malfunction indicator lamp (MIL). When the
engine starts to run and no malfunction is detected in the system, MIL goes OFF but if a malfunction was or is de-
tected, MIL remains ON even when the engine is running.
INSPECTION
STEPACTIONYESNO
1MIL Power Supply Check
1) Turn ignition switch ON.
Do other indicator / warning lights in
combination meter comes ON?Go to Step 2.“IG COIL METER” fuse blown,
main fuse blown, ignition
switch malfunction, “B/W”
circuit between “IG COIL
METER” fuse and
combination meter or poor
coupler connection at
combination meter.
2ECM (PCM) Power and Ground Circuit
Check
Does engine start?Go to Step 3.Go to TABLE A-3 ECM (PCM)
POWER AND GROUND
CIRCUIT CHECK.
If engine is not cranked, go to
DIAGNOSIS in SECTION 8A.
3MIL Circuit Check
1) Turn ignition switch OFF and disconnect
connectors from ECM (PCM).
2) Check for proper connection to ECM
(PCM) at terminal C02-17.
3) If OK, then using service wire, ground
terminal C02-17 in connector
disconnected.
Does MIL turn on at ignition switch ON?Substitute a known-
good ECM (PCM) and
recheck.Bulb burned out or “V/Y” wire
circuit open.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-41
TABLE A-2 MALFUNCTION INDICATOR LAMP CIRCUIT CHECK – LAMP
REMAINS “ON” AFTER ENGINE STARTS
WIRING DIAGRAM / CIRCUIT DESCRIPTION – Refer to table A-1.
INSPECTION
STEPACTIONYESNO
1Diagnostic Trouble Code (DTC) check
1) Check DTC referring to DTC CHECK section.
Is there any DTC(s)?Go to Step 2 of ENGINE
DIAG. FLOW TABLE.Go to Step 2.
2DTC check
Start engine and recheck DTC while engine
running.
Is there any DTC(s)?Go to Step 3.
3MIL Circuit check
1) Turn OFF ignition switch.
2) Disconnect connectors from ECM (PCM).
Does MIL turn ON at ignition switch ON?“V/Y” wire circuit
shorted to ground.Substitute a known-good
ECM (PCM) and
recheck.

Main fuse Ignition switch
Main fuseMalfunction indicator lamp in combination meter
Relay box“IG COIL METER”
6-42 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
TABLE A-3 ECM (PCM) POWER AND GROUND CIRCUIT CHECK – MIL
DOESN’T LIGHT AT IGNITION SWITCH ON AND ENGINE DOESN’T
START THOUGH IT IS CRANKED UP
CIRCUIT DESCRIPTION
When the ignition switch tuned ON, the main relay turns ON (the contact point closes) and the main power is sup-
plied to ECM (PCM).
INSPECTION
STEPACTIONYESNO
1Main Relay Operating Sound Check
Is operating sound of main relay heard at ignition switch ON?Go to Step 5.Go to Step 2.
2Main Relay Check
1) Turn OFF ignition switch and remove main relay (1).
2) Check for proper connection to main relay (1) at terminal
3 and 4.
3) Check resistance between each two terminals. See Fig. 1
and 2.
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. 3.
Is main relay in good condition?Go to Step 3.Replace main
relay.
3Fuse Check
Is main “FI” fuse in good condition?Go to Step 4.Check for short in
circuits connected
to this fuse.
4ECM (PCM) Power Circuit Check
1) Turn OFF ignition switch, disconnect connectors from ECM
(PCM) and install main relay.
2) Check for proper connection to ECM (PCM) at terminals
C03-20, C02-2, C02-15 and C02-22.
3) If OK, then measure voltage between terminal C03-20 and
ground, C02-22 and ground with ignition switch ON.
Is each voltage 10 – 14 V?Go to Step 5.“B/W”, “W/R” or
“Bl / B” circuit
open.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-43
Fig. 1 for Step 2 Fig. 2 for Step 2 Fig. 3 for Step 2
1. Main relay
2. Relay box
STEPACTIONYESNO
5ECM (PCM) Power Circuit Check
1) Using service wire, ground terminal C02-22 and
measure voltage between terminal C02-2 and
ground at ignition switch ON.
Is it 10 – 14 V?Check ground circuits
“Bl / B” and “W / Bl” for
open.
If OK, then substitute a
known-good ECM
(PCM) and recheck.Go to Step 6.
6Is operating sound of main relay heard in Step 1?Go to Step 7.“W / R” or “W / Bl” wire
open.
7Main Relay Check
1) Check main relay according to procedure in
Step 2.
Is main relay in good condition?“W / R” or “W / Bl” wire
open.Replace main relay.

MAP sensorTo TP sensor
To other sensors
6-44 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0105 MANIFOLD ABSOLUTE PRESSURE (MAP) CIRCUIT
MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

MAP: 5 kPa, 37.5 mmHg or less
(Low pressure – High vacuums – Low voltage)
or

MAP: 130 kPa, 975 mmHg or more
(High pressure – Low vacuums – High voltage)
“G” circuit open

“Lg” circuit open or shorted to ground

“Lg / R” circuit open or shorted to ground

MAP sensor malfunction

ECM (PCM) malfunction
NOTE:

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

When DTC P0105, P0110, P0115 and / or P0120 are indicated together, it is possible that “G” 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) 6-45
Fig. 1 for Step 2 Fig. 2 for Step 3
Scan tool
DLC
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE”
performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check MAP Sensor and Its Circuit.
1) Connect scan tool to DLC with ignition
switch OFF.
2) Turn ignition switch ON.
3) Check intake manifold pressure.
See Fig. 1.
Is it 130 kPa or more or 5 kPa or less?Go to Step 3.Intermittent trouble.
Check for intermittent
referring to
“INTERMITTENT AND
POOR CONNECTION” in
Section 0A.
3Check Wire Harness.
1) Disconnect MAP sensor connector with
ignition switch OFF.
2) Check for proper connection of MAP
sensor at “Lg / R” and “G” wire
terminals.
3) If OK, then with ignition switch ON, check
voltage at each of “Lg” and “Lg / R” wire
terminals. See Fig. 2.
Is voltage about 4 – 6 V at each terminal?Go to Step 4.“Lg” wire open or
shorted to ground circuit or
shorted to power circuit,
“Lg / R” wire open or
shorted to ground, poor
C01-5 connection or
C01-1 connection.
If wire and connection are
OK, confirm that MAP
sensor is normal and then
substitute a known-good
ECM (PCM) and recheck.
NOTE: When battery
voltage is applied to
“Lg” wire, it is possible
that MAP sensor is also
faulty.
4Check MAP sensor according to “MAP
Sensor Individual Check” in Section 6E1.
Is it in good condition?“Lg” wire shorted to
“Lg / R” wire, “G” wire
open, poor C01-9
connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace MAP sensor.

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.