Page 189 of 557
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-33
1. ECM (PCM)
2. ECM (PCM) couplers
(Viewed from harness side)
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 6E2.
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.
Page 194 of 557
INFORMATION SENSORS
-1. MAP sensor
-2. TP sensor
-3. IAT sensor
-4. ECT sensor
-5. Heated oxygen sensor-1
5-1. Heated oxygen sensor-2
-6. VSS (A / T)
-7. Transmission range switch (A / T)
-8. Battery
-9. CMP sensor
-10. CKP sensor
-11. Fuel level sensor (gauge) (in fuel tank)
-12. PSP switch
-13. A / C control module (if equipped)
-14. VSS (speedometer) (M / T)OTHERS
A: ECM (PCM)
B: Main relay
C: EVAP canister
D: Data link connector CONTROL DEVICES
a: Fuel injector
b: EVAP canister purge valve
c: Fuel pump relay
d: EGR valve (step motor)
e: Malfunction indicator lamp
f: Ignition coil assembly
g: Radiator fan control relay
h: IAC valve
6-1-38 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
COMPONENT LOCATION
Page 197 of 557

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.
Page 201 of 557

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.
Page 253 of 557

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-97
Fuse box Main
fuse
DOME
RADIO
“LAMP”
DTC P1510 ECM (PCM) BACK-UP POWER SUPPLY MALFUNCTION
CIRCUIT DESCRIPTION
Battery voltage is supplied so that diagnostic trouble code memory, values for engine control learned by ECM
(PCM), etc. are kept in ECM (PCM) even when the ignition switch is turned OFF.
DTC DETECTING CONDITION
POSSIBLE CAUSE
Low voltage at terminal C02-7 after starting engine.“W” circuit open
ECM (PCM) malfunction
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and run it at idle for 1 min.
2) Select “DTC” mode on scan tool and check DTC.
INSPECTION
STEPACTIONYESNO
1Check for voltage at terminal C02-7 of ECM
(PCM)connector connected, under each
condition, ignition switch OFF and engine
running.
Is it 10 – 14 V at each condition?Poor C02-7 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.“W” circuit open.
Page 255 of 557

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-99
Main
fuseIgnition
switch
Main relay
Fuel pump relay Main relay
Fuel pump
CAUTION: Check to make sure that connection is
made between correct terminals. Wrong connection
can cause damage to ECM (PCM), wire harness, etc.
TABLE B-2 FUEL PUMP AND ITS CIRCUIT CHECK
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE
DIAG. FLOW
TABLE”.
2Check Fuel Pump Control System for Operation. See Fig. 1.
Is fuel pump heard to operate for 2 sec. after ignition switch
ON?Fuel pump circuit
is in good
condition.Go to Step 3.
3Check Fuel Pump for Operation.
1) Remove fuel pump relay from relay box with ignition
switch OFF.
2) Check for proper connection to relay at each terminals.
3) If OK, using service wire, connect terminals C44-3 and
C44-4 of relay connector. See Fig. 2.
Is fuel pump heard to operate at ignition switch ON?Go to Step 4.“P”, “B” or “R/B”
circuit open or fuel
pump malfunction.
4Check Fuel Pump Relay for Operation.
1) Check resistance between each two terminals of fuel
pump relay. See Fig.3.
Between terminals “c” and “d”: Infinity
Between terminals “a” and “b”: 100 – 150 Ω
2) Check that there is continuity between terminals “c” and
“d” when battery is connected to terminals “a” and “b”. See
Fig. 3.
Is fuel pump relay in good condition?“Y/Bl” circuit open
or poor C02-19
connection.
If wire and
connection are
OK, substitute a
known-good ECM
(PCM) and
recheck.Replace fuel pump
relay.
Page 262 of 557

6-1-106 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
Radiator cooling fan relay
To
ECM
Main
relay
Relay
box
“RDTR”
(Radiator fan)Radiator cooling
Fan motor
TABLE B-7 RADIATOR COOLING FAN CONTROL SYSTEM CHECK
INSPECTION
STEPACTIONYESNO
1Check Fan Control System.
1) Connect scan tool to DLC with ignition switch OFF.
2) Start engine and select “DATA LIST” mode on scan tool.
3) Warm up engine until coolant temp. is 97.5C, 208F or
higher and A / C switch turn OFF. (If engine coolant temp.
does not rise, check engine cooling system or ECT sensor.)
See Fig. 1.
Is radiator cooling fan started when engine coolant temp.
reached above temp.?Radiator cooling
fan control
system is in good
condition.Go to Step 2.
2Check Radiator Cooling Fan Relay and Its Circuit.
1) Check DTC and pending DTC with scan tool.
Is DTC P0480 displayed?Go to DTC
P0480 Diag.
Flow Table.Go to Step 3.
3Check Radiator Cooling Fan Relay.
1) Turn ignition switch OFF and remove radiator cooling fan
relay.
2) Check for proper connection to relay at terminals “c” and “d”.
3) If OK, check that there is continuity between “c” and “d” when
battery is connected to terminals “a” and “b”. See Fig. 2.
Is check result satisfactory?Go to Step 4.Replace radiator
fan relay.
4Check Radiator Cooling Fan.
1) Turn ignition switch OFF.
2) Disconnect cooling fan motor connector.
3) Check for proper connection to motor at “Bl / R” and “B”
terminals.
4) If OK, connect battery to motor and check for operation.
See Fig. 3.
Is it in good condition?“Bl / W”, “Bl / R” or
“B” circuit open.Replace radiator
cooling fan
motor.
Page 263 of 557
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-107
Fig. 1 for Step 1 Fig. 2 for Step 3
Fig. 3 for Step 4When using SUZUKI scan tool:
1. Radiator cooling fan relay
1. Battery
2. Radiator fan motor coupler