
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-47
TABLE A-2 MALFUNCTION INDICATOR LAMP CIRCUIT CHECK - LAMP
REMAINS “ON” AFTER ENGINE STARTS
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Refer to table A-1.
INSPECTION
3 MIL Circuit Check
1) Turn ignition switch OFF and disconnect
connectors from ECM.
2) Check for proper connection to ECM at ter-
minal G02-1 (Case of TYPE A. See NOTE)
or G02-9 (Case of TYPE B. See NOTE).
3) If OK, then using service wire, ground termi-
nal G02-1 (Case of TYPE A. See NOTE) or
G02-9 (Case of TYPE B. See NOTE) in con-
nector disconnected.
Does MIL turn on at ignition switch ON?Substitute a known-good
ECM and recheck.Bulb burned out or “PPL/
YEL” (Case of TYPE A.
See NOTE) or “PPL/
WHT” (Case of TYPE B.
See NOTE) wire circuit
open.
Test switch terminal cir-
cuit grounded (vehicle
without immobilizer indi-
cator lamp) Step Action Yes No
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
Step Action Yes No
1 Diagnostic 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
1) Start engine and recheck DTC while
engine running.
Is there any DTC(s)?Go to Step 3.
3 MIL Circuit Check
1) Turn OFF ignition switch.
2) Disconnect connectors from ECM.
Does MIL turn ON at ignition switch ON?“PPL/YEL” (Case of TYPE A.
See NOTE) or “PPL/WHT”
(Case of TYPE B. See NOTE)
wire circuit shorted to ground.Substitute a known-good
ECM and recheck.

6-48 ENGINE GENERAL INFORMATION AND DIAGNOSIS
TABLE A-3 MIL CHECK - MIL FLASHES AT IGNITION SWITCH ON (VEHICLE
WITHOUT IMMOBILIZER INDICATOR LAMP)
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Refer to TABLE A-1.
INSPECTION
TABLE A-4 MIL CHECK - MIL DOES NOT FLASH OR JUST REMAINS ON EVEN
WITH GROUNDING DIAGNOSIS SWITCH TERMINAL (VEHICLE WITHOUT
IMMOBILIZER INDICATOR LAMP)
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Refer to TABLE A-1.
INSPECTION
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
Step Action Yes No
1 MIL Flashing Pattern Check
1) Turn ignition switch ON.
Does lamp flashing pattern indicate diag-
nostic trouble code?Go to Step 2. Substitute a known-good ECM
and recheck.
2 Diag. Switch Circuit Check
Is diag. switch terminal connected to
ground via service wire?System is in good condi-
tion.“PPL/WHT” circuit for monitor
connector shorted to ground. If
circuit is OK substitute a known-
good ECM and recheck.
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
Step Action Yes No
1 MIL Circuit Check
1) Turn ignition switch OFF and disconnect connec-
tors from ECM.
Does MIL turn ON at ignition switch ON?“PPL/YEL” (Case of TYPE A.
See NOTE) or “PPL/WHT”
(Case of TYPE B. See NOTE)
circuit shorted to ground.Go to Step 2.
2 ECM/PCM Connection Check
1) Turn ignition switch OFF.
Is connector (C42-27 (Case of TYPE A. See NOTE)
or C41-14 (Case of TYPE B. See NOTE) connection)
connected to ECM/PCM properly?Go to Step 3. Poor connector connec-
tion.
3 Diag. Switch Terminal Circuit Check
1) Connect connectors to ECM.
2) Using service wire, ground C42-27 (Case of
TYPE A. See NOTE) or C41-14 (Case of TYPE
B. See NOTE) connection) terminal with connec-
tors connected to ECM.
3) Turn ignition switch ON.
Does MIL flash?“PPL/WHT” or “BLK” circuit in
monitor connector is open.Substitute a known-good
ECM and recheck.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-49
TABLE A-5 ECM POWER AND GROUND CIRCUIT CHECK - MIL DOESN’T
LIGHT AT IGNITION SWITCH ON AND ENGINE DOESN’T START THOUGH IT IS
CRANKED UP
WIRING DIAGRAM
CIRCUIT DESCRIPTION
When the ignition switch tuned ON, the main relay turns ON (the contact point closes) and the main power is
supplied to ECM.
1. BATT fuse 3. IG METER fuse 5. Monitor connector
2. Main fuse box 4. To battery 6. MIL (if equipped)
[A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
1
12V5V
ECM
23
+BB
DA
C
BLK/WHT
BRN/WHT
BLK/RED
BLK/RED
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
BLK
DN
TS
GNDMON
PPL/WHTC42-27 [A]
C42-16 [A]
PNK/BLUC42-28 [A]
7 4
G02-1 [A]IG1PPL/YEL [A]
5
6IG1
WHT/GRN
BLK/WHT
G02-6 [A]
C41-5 C41-6 C41-10 C41-11 [B]C41-14 [B]
C41-15 [B]
C41-8 [B]
G02-9 [B]PPL/WHT [B]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.

6-50 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION
Step Action Yes No
1 Main Relay Operating Sound Check
Is operating sound of main relay heard at ignition switch
ON?Go to Step 5. Go to Step 2.
2 Main Relay Check
1) Turn OFF ignition switch and remove main relay (1).
2) Check for proper connection to main relay (1).
3) Check resistance between each two terminals. See Fig.
1 and 2.
Between terminals C and D : Infinity
Between terminals A and B : 56 – 146 Ω
4) Check that there is continuity between terminals C and
D when battery is connected to terminals A and B. See
Fig. 3.
Is main relay in good condition?Go to Step 3. Replace main relay.
3 Fuse Check
Is main fuse in good condition? See Fig. 4.Go to Step 4. Check for short in
circuits connected
to this fuse.
4 ECM Power Circuit Check
1) Turn OFF ignition switch, disconnect connectors from
ECM and install main relay.
2) Check for proper connection to ECM at terminals G02-6
(Case of TYPE A. See NOTE) or C41-11 (Case of TYPE
B. See NOTE), C41-10, C41-5 and C41-6.
3) If OK, then measure voltage between terminal G02-6
(Case of TYPE A. See NOTE) or C41-11 (Case of TYPE
B. See NOTE) and ground, C41-10 and ground with igni-
tion switch ON.
Is each voltage 10 – 14 V?Go to Step 5.“BLK/WHT”, “BLK/
YEL” or “BRN/
WHT” circuit open.
5 ECM Power Circuit Check
1) Using service wire, ground terminal C41-10 and mea-
sure voltage between terminal C41-5 and ground at igni-
tion switch ON.
Is it 10 – 14 V?Check ground cir-
cuits “BRN/WHT”
and “BLK/YEL” for
open.
If OK, then substi-
tute a known-good
ECM and recheck.Go to Step 6.
6 Is operating sound of main relay heard in Step 1? Go to Step 7.“BLK/YEL” or “BLK/
RED” wire open.
7 Main relay check
1) Check main relay according to procedure in Step 2.
Is main relay in good condition?“BLK/YEL” or “BLK/
RED” wire open.Replace main relay.

6-60 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0120 (DTC NO.13) THROTTLE POSITION CIRCUIT MALFUNCTION
WIRING DIAGRAM / CIRCUIT DESCRIPTION
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.
[A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
DTC DETECTING CONDITION POSSIBLE CAUSE
Signal voltage high
or
Signal voltage low“ORN” circuit open
“GRY/BLU” circuit open or shorted to ground
“GRY/RED” circuit open or shorted to power or ground
TP sensor malfunction
ECM malfunction
C42-10
C42-22
5V5V
ECM
GRY/RED
GRY/BLU
ORN
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
C42-16 [B] C41-3 [A]
NOTE:
For TYPE A and TYOE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
When DTC P0105 (No.11), P0110 (No.18), P0115 (No.19) and P0120 (No.13) are indicated together, it
is possible that “ORN” or “GRY/RED” circuit is open.
When this DTC and P1700 are stored together, also clear DTC stored in TCM after completion of
repair.
When this DTC and DTC P0105 (No.11) are indicated together, it is possible that “GRY/RED” circuit
is open.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-61
INSPECTION
Fig. 1 for Step 2Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check 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 throt-
tle valve from idle position to full open posi-
tion. 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 0 A.
3 Check Wire Harness.
1) Disconnect connector from TP sensor with
ignition switch OFF.
2) Check for proper connection to TP sensor at
“GRY/RED”, “GRY/BLU” and “ORN” wire
terminals.
3) If OK, then with ignition switch ON, check
voltage between each of “GRY/RED” or
“GRY/BLU” wire terminals and body
ground. See Fig. 2.
Is voltage about 4 – 6 V at each terminal?Go to Step 4.“GRY/RED” wire open,
“GRY/RED” wire shorted
to ground circuit or power
circuit or “GRY/BLU” wire,
“ORN” wire open or
shorted to ground circuit
or poor C42-22 or C41-3
(For TYPE A, See NOTE)
or C42-16 (For TYPE B,
See NOTE) connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
4 Check 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 : 100 Ω – 20 kΩ
varying according to throttle valve opening
Are measured values within specifications?“ORN” wire open or poor
C42-10 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.Replace TP sensor.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-63
DTC P0121 THROTTLE POSITION CIRCUIT RANGE/PERFORMANCE PROB-
LEM
WIRING DIAGRAM / CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF. Clear DTC with ignition switch ON, check vehicle and environmental condition for :
–Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 158°F or lower
–Engine coolant temp. : 70 – 110°C, 158 – 230°F
2) Warm up engine to normal operating temperature.
3) Increase vehicle speed to 30 – 40 mph, 50 – 60 km/h in 3rd gear or “D” range and hold throttle valve at that
opening position for 1 min.
4) Stop vehicle.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
[A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
C42-10
C42-22
5V5V
ECM
GRY/RED
GRY/BLU
ORN
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
C42-16 [B]C41-3 [A]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
DTC DETECTING CONDITION POSSIBLE CAUSE
DTC will set when the following conditions are detected.
After engine warmed up.
While vehicle running at specified engine speed.
No change in intake manifold pressure (constant throttle opening)
Difference between actual throttle opening (detected from TP sensor)
and opening calculated by ECM (Obtained on the basis of engine
speed and intake manifold pressure) in larger than specified value.
✱2 driving cycle detection logic, continuous monitoringTP sensor malfunction
High resistance in the circuit
ECM malfunction
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent 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, on a level road.

6-64 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION
Fig. 1 for Step 3Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Is SUZUKI scan tool available? Go to Step 3. Go to Step 4.
3 Check TP Sensor and its Circuit.
1) Turn ignition switch OFF and connect
SUZUKI scan tool to DLC.
2) Turn ignition switch ON and check TP sen-
sor output voltage when throttle valve is at
idle position and fully opened. See Fig. 1
and 3.
Dose voltage vary within specified value linearly
as shown in figure?If voltmeter was used,
check terminal C41-3 (For
TYPE A, See NOTE) or
C42-16 (For TYPE B, See
NOTE) for poor connec-
tion.
If OK, substitute a known-
good ECM and recheck.Go to Step 5.
4 Check TP Sensor and Its Circuit.
1) Turn ignition switch ON.
2) Check voltage at terminal C41-3 (For TYPE
A, See NOTE) or C42-16 (For TYPE B, See
NOTE) of ECM 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 C41-3 (For
TYPE A, See NOTE) or
C42-16 (For TYPE B, See
NOTE) for poor connec-
tion.
If OK, substitute a known-
good ECM and recheck.Go to Step 5.
5 Check 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 : 4.0 – 6.0 kΩ
Between 1 and 3 : 0.02 – 6.0 kΩ, varying
according to throttle valve opening.
Are measured values as specified?High resistance in “GRY/
RED”, “GRY/BLU” or
“ORN” circuit.
If wire and connection are
OK, substitute a known-
good ECM and recheck.Replace TP sensor.
[A] : When using SUZUKI scan tool:
[ A]