Main
fuseIgnition
switch
Main
relay Malfunction indicator lamp in combination meter
Relay
box
Fuse box
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-41
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 – 150 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
C03-6, C02-10, C02-5 and C02-6.
3) If OK, then measure voltage between terminal C03-6 and
ground, C02-10 and ground with ignition switch ON.
Is each voltage 10 – 14 V?Go to Step 5.“B/W”, “W/R” or
“Gr” circuit open.
6-1-44 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
MAP Sensor Individual Check
1) Disconnect coupler from MAP sensor (1).
2) Remove MAP sensor (1).
3) Arrange 3 new 1.5 V batteries (2) in series (check that total volt-
age is 4.5 – 5.0 V) and connect its positive terminal to “Vin” termi-
nal of sensor and negative terminal to “Ground” terminal. Then
check voltage between “Vout” and “Ground”.
Also, check if voltage reduces when vacuum is applied up to 400
mmHg by using vacuum pump (3).
Output voltage (Vin voltage 4.5 – 5.5 V, ambient temp. 20 –
30C, 68 – 86F)
ALTITUDE
BAROMETRICOUTPUT
(Reference)PRESSUREVOLTAGE
(ft)(m)(mmHg)(kPa)(V)
0
0
760
100
3343
2 000
610
707
94
3.3 – 4.3
2 001
611
Under 70794
3041
5 000
1 524over 634
85
3.0 – 4.1
5 001
1 525
Under 63485
2737
8 000
2 438over 567
76
2.7 – 3.7
8 001
2 439
Under 56776
25–33
10 000
3 048over 526
70
2.5 – 3.3
If check result is not satisfactory, replace MAP sensor (1).
4) Install MAP sensor (1) securely.
5) Connect MAP sensor (1) coupler securely.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-45
Fig. 1 for Step 2 Fig. 2 for Step 3
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 114.7 kPa or more or 4.9 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 “Gr” and “G” wire terminals.
3) If OK, then with ignition switch ON, check
voltage at each of “P” and “Gr” wire
terminals. See Fig. 2.
Is voltage about 4 – 6 V at each terminal?Go to Step 4.“P” wire open or shorted to
ground circuit or shorted to
power circuit, “Gr” wire
open or shorted to ground,
poor C03-5 connection or
C01-22 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
“P” wire, it is possible
that MAP sensor is also
faulty.
4Check MAP sensor according to “MAP
Sensor Individual Check” below.
Is it in good condition?“P” wire shorted to “Gr”
wire, “G” wire open,
poor C01-10 connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace MAP sensor.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-47
Fig. 1 for Step 2 Fig. 2 for Step 3 Fig. 3 for Step 4
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 / R” and “G” wire terminals.
3) If OK, then with ignition switch ON, is voltage
applied to “Gr / R” wire terminal about 4 – 6 V?
See Fig. 2.Go to Step 5.“Gr / R” wire open or
shorted to power, or
poor C01-15
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 / R” 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 / R” wire open or
poor C01-10
connection.
If wire and connection
are OK, substitute a
known-good ECM
(PCM) and recheck.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-49
Fig. 1 for Step 2 Fig. 2 for Step 5 Fig. 3 for Step 6
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.“Lg / R” 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 “Lg / R” 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.“Lg / R” 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.
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
C01-10 connection.
If wire and connection
are OK, substitute a
known-good ECM
(PCM) and recheck.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-51
Fig. 1 for Step 2 Fig. 2 for Step 3 Fig. 3 for Step 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) 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 0A.
3Check Wire Harness.
1) Disconnect connector from TP sensor
with ignition switch OFF.
2) Check for proper connection to TP sensor
at “P”, “Gr” and “G” wire terminal.
3) If OK, then with ignition switch ON, check
voltage at each of “P” and “Gr” wire
terminals. See Fig. 2.
Is voltage about 4 – 6 V at each terminal?Go to Step 4.“P” wire open, “P” wire
shorted to ground circuit or
power circuit or “G” wire,
“Gr” wire open or shorted
to ground circuit or poor
C01-22 or C03-5
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 2: 2.5 – 6.0 kΩ
Between 1 and 3: 170 Ω – 15.5 kΩ
Are measured values within specifications?“G” wire open or poor
C01-10 connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace TP sensor.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-53
Fig. 1 for Step 2 Fig. 2 for Step 2 Fig. 3 for Step 2
Fig. 4 for Step 3
Closed
(condition “A”)Fully open
Throttle Opening When using SUZUKI scan tool:
When not using SUZUKI scan tool:
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE
DIAG. FLOW
TABLE”.
2Check TP Sensor and Its Circuit.
When using SUZUKI scan tool:
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 3.
When not using SUZUKI scan tool:
1) Turn ignition switch ON.
2) Check voltage at terminal C03-5 of ECM (PCM) 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 C03-5 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. 4.
Between 1 and 2: 2.5 – 6.0 kΩ
Between 1 and 3: 170 Ω – 15.5 kΩ, varying according to
throttle valve opening.
Are measured values as specified?High resistance in
“P”, “Gr” or “G”
circuit.
If wire and
connection are
OK, substitute a
known-good ECM
(PCM) and
recheck.Replace TP
sensor.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-59
Fig. 1 for Step 2 Fig. 2 for Step 3
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go t o“ENGINE DIAG.
FLOW TABLE”.
2Check Heater for Operation.
1) Check voltage at terminal C01-7. See Fig. 1.
2) Warm up engine to normal operating temperature.
3) Stop engine.
4) Turn ignition switch ON and Check voltage atIntermittent trouble
Check for intermittent
referring to
“Intermittent and
Poor Connection”Go to Step 3.
terminal C01-7. See Fig. 1. Voltage should be
over 10 V.
5) Start engine, run it at idle and check voltage at the
same terminal. Voltage should be below 1.9 V.
Are check results are specified?in Section 0A.
3Check Heater of Sensor-1.
1) Disconnect HO2S-1 coupler with ignition switch
OFF.
2) Check for proper connection to HO2S-1 at “B/W”
and “Bl” wire terminals.
3) If OK, then check heater resistance. See Fig. 2.
Is it 11.7 – 14.3 Ω at 20C, 68F?“Bl” wire open or
shorted to ground or
poor connection at
C01-7. If wire and
connection are OK,
substitute a
known-good ECM
(PCM) and recheck.Replace HO2S-1.