ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-29
Excessive detona-
tion
(Engine makes con-
tinuously sharp
metallic knocks that
change with throttle
opening. Sounds
like pop corn pop-
ping.)Faulty spark plug Spark plugs in Section 6F1.
Loose connection of high-tension cord High-tension cords in Section 6F1.
Engine overheating Refer to “Overheating” section.
Clogged fuel filter (faulty fuel pump) or fuel
linesDiagnostic Flow Table B-1 or B-2.
Air inhaling from intake manifold or throttle
body gasket
Malfunctioning EGR valve (if equipped) EGR system in Section 6E1.
Poor performance of knock sensor, ECT sen-
sor or MAP sensorKnock sensor in Section 6, ECT sensor
or MAP sensor in Section 6E1.
Faulty fuel injector(s) Diagnostic Flow Table B-1.
Faulty ECM
Excessive combustion chamber deposits Piston and cylinder head cleaning in
Section 6A1.
Engine has no
powerFaulty spark plug Spark plugs in Section 6F1.
Faulty ignition coil with ignitor Ignition coil in Section 6F1.
Leaks, loose connection or disconnection of
high-tension cordHigh-tension cords in Section 6F1.
Faulty knock sensor Knock sensor malfunction in this sec-
tion.
Clogged fuel hose or pipe Diagnostic Flow Table B-3.
Malfunctioning fuel pump Diagnostic Flow Table B-2.
Air inhaling from intake manifold gasket or
throttle body gasket
Engine overheating Refer to “Overheating” section.
Engine has no
powerMalfunctioning EGR valve (if equipped) EGR system inspection in Section 6E1.
Maladjusted accelerator cable play Accelerator cable play in Section 6E1.
Poor performance of TP sensor, ECT sensor
or MAP sensorTP sensor, ECT sensor or MAP sensor
in Section 6E1.
Faulty fuel injector(s) Diagnostic Flow Table B-1.
Faulty ECM
Dragging brakes Trouble diagnosis in Section 5.
Slipping clutch Trouble diagnosis in Section 7C.
Low compression Previously outlined. Condition Possible Cause Correction
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-31
SCAN TOOL DATA
As the data values given below are standard values estimated on the basis of values obtained from the normally
operating vehicles by using a scan tool, use them as reference values. Even when the vehicle is in good condi-
tion, there may be cases where the checked value does not fall within each specified data range. Therefore,
judgment as abnormal should not be made by checking with these data alone.
Also, conditions in the below table that can be checked by the scan tool are those detected by ECM and output
from ECM as commands and there may be cases where the engine or actuator is not operating (in the condi-
tion) as indicated by the scan tool. Be sure to use the timing light to check the ignition timing.
NOTE:
With the generic scan tool, only star (
✱) marked data in the table below can be read.
The triangle (
∆) marked data in the table below can not be read for vehicle without immobilizer indi-
cator lamp.
When checking the data with the engine running at idle or racing, be sure to shift M/T gear to the
neutral gear position and A/T gear to the “Park” position and pull the parking brake fully. Also, if
nothing or “no load” is indicated, turn OFF A/C, all electric loads, P/S and all the other necessary
switches.
SCAN TOOL DATA VEHICLE CONDITION NORMAL CONDITION/
REFERENCE VALUES
✱FUEL SYSTEM B1
(FUEL SYSTEM STATUS)At specified idle speed after warming up CLOSED (closed loop)
✱CALC LOAD
(CALCULATED LOAD
VALUE)At specified idle speed with no load after
warming up3 – 9%
At 2500 r/min with no load after warming up 12 – 17%
✱COOLANT TEMP.
(ENGINE COOLANT
TEMP.)At specified idle speed after warming up 80 – 100°C, 176 – 212°F
✱SHORT FT B1
(SHORT TERM FUEL
TRIM)At specified idle speed after warming up– 20 – +20%
✱LONG FT B1
(LONG TERM FUEL TRIM)At specified idle speed after warming up– 15 – +15%
✱MAP
(INTAKE MANIFOLD
ABSOLUTE PRESSURE)At specified idle speed with no load after
warming up30 – 37 kPa,
220 – 280 mmHg
✱ENGINE SPEED At idling with no load after warming up Desired idle speed
±50 r/min
✱VEHICLE SPEED At stop 0 km/h, 0 MPH
✱IGNITION ADVANCE
(IGNITION TIMING
ADVANCE FOR NO.1 CYL-
INDER)At specified idle speed with no load after
warming up6 – 16° BTDC
✱INTAKE AIR TEMP. At specified idle speed after warming up Ambient temp. :
+15°C (59°F)
–5°C (23°F)
✱MAF
(MASS AIR FLOW RATE)At specified idle speed with no load after
warming up1 – 4 gm/sec
At 2500 r/min with no load after warming up 4 – 9 gm/sec
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-33
SCAN TOOL DATA DEFINITIONS :
FUEL SYSTEM (FUEL SYSTEM STATUS)
Air/fuel ratio feedback loop status displayed as either open or closed loop. Open indicates that ECM ignores
feedback from the exhaust oxygen sensor.
Closed indicates final injection duration is corrected for oxygen sensor feedback.
CALC LOAD (CALCULATED LOAD VALUE, %)
Engine load displayed as a percentage of maximum possible load. Value is calculated mathematically using the
formula : actual (current) intake air volume ÷ maximum possible intake air volume x 100%.
COOLANT TEMP. (ENGINE COOLANT TEMPERATURE, °C, °F)
It is detected by engine coolant temp. sensor
SHORT FT B1 (SHORT TERM FUEL TRIM, %)
Short term fuel trim value represents short term corrections to the air/fuel mixture computation. A value of 0 indi-
cates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies an
enleanment correction.
LONG FT B1 (LONG TERM FUEL TRIM, %)
Long term fuel trim Value represents long term corrections to the air/fuel mixture computation. A value of 0 indi-
cates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies an
enleanment correction.
MAP (INTAKE MANIFOLD ABSOLUTE PRESSURE, kPa, inHg)
It is detected by manifold absolute pressure sensor and used (among other things) to compute engine load.
ENGINE SPEED (rpm)
It is computed by reference pulses from crankshaft position sensor.
VEHICLE SPEED (km/h, MPH)
It is computed based on pulse signals from vehicle speed sensor.PNP SIGNAL (PARK/NEU-
TRAL POSITION SIGNAL)
A/T onlyIgnition switch
ONSelector lever in “P” or “N”
positionP/N Range
Selector lever in “R”, “D”,
“2” or “L” positionD Range
EGR VALVE At specified idle speed after warming up 0%
∆FUEL TANK LEVEL–0 – 100%
BAROMETRIC PRESS–Display the barometric pres-
sure
FUEL PUMP Within 3 seconds after ignition switch ON or
engine runningON
Engine stop at ignition switch ON. OFF
BRAKE SW Ignition switch
ONBrake pedal is depressing ON
Brake pedal is releasing OFF
BLOWER FAN Ignition switch
ONBlower fan switch ON ON
Blower fan switch OFF OFF
A/C MAG CLUTCH Ignition switch
ONA/C switch ON ON
A/C switch OFF OFF SCAN TOOL DATA VEHICLE CONDITION NORMAL CONDITION/
REFERENCE VALUES
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-73
6) Repeat above steps 5) 4 times.
7) Increase vehicle speed to about 50 mph (80 km/h) in 3rd gear or 2 range.
8) Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) for
10sec. or more.
9) Stop vehicle (don’t turn ignition switch OFF) and run engine at idle for 2 min.
After this step 9), if “Oxygen Sensor Monitoring TEST COMPLETED” is displayed in “READINESS TESTS”
mode and DTC is not displayed in “DTC” mode, confirmation test is completed.
If “TEST NOT COMPLTD” is still being displayed, proceed to next step 10).
10) Drive vehicle under usual driving condition for 10 min. (or vehicle is at a stop and run engine at idle for 10
min. or longer)
11) Stop vehicle (don’t turn ignition switch OFF). Confirm test results according to “Test Result Confirmation
Flow Table” in “DTC CONFIRMATION PROCEDURE” of DTC P0420.
INSPECTION
Usual driving : Driving at 30 – 40 mph, 50 – 60 km/h including short stop according to traffic signal. (under driving condition other than high-load, high-engine
speed, rapid accelerating and decelerating)
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check Exhaust System for leakage, loose con-
nection and damage.
Is it good condition?Go to Step 3. Repair or replace.
3 Check HO2S-2 and Its Circuit.
Was HO2S-2 output voltage indicated on scan
tool in step 3) of DTC confirmation test less
than 1.275 V?Go to Step 4.“BRN”, “YEL” or “ORN”
circuit short to power sup-
ply circuit or HO2S-2 mal-
function.
4 Check Short Term Fuel Trim.
Did short term fuel trim very within – 20 – + 20%
range in step 3) of DTC confirmation test?Check “BRN”, “YEL” or
“ORN” wire for open and
short, and connection for
poor connection. If wire
and connection are OK,
replace HO2S-2.Check fuel system. Go to
DTC P0171/P0172 Diag.
Flow Table.
6-106 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 Idle Air Control System.
1) Connect SUZUKI scan tool to DLC with igni-
tion switch OFF, set parking brake and
block drive wheels.
2) Warm up engine to normal operating tem-
perature.
3) Clear DTC and select “MISC TEST” mode
on SUZUKI scan tool. See Fig. 1.
Is it possible to control (increase and reduce)
engine idle speed by using SUZUKI scan tool? Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Go to Step 5.
4 Check Idle Air Control System.
1) Remove IAC valve from throttle body refer-
ring to “IAC Valve Removal” in Section 6E1.
2) Check IAC valve for operation referring to
“IAC Valve Inspection” in Section 6E1. See
Fig. 2.
Is check result satisfactory?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Go to Step 5.
5 Check Wire Harness for open and short.
1) Turn ignition switch OFF.
2) Disconnect IAC valve connector.
3) Check for proper connection to IAC valve at
each terminals.
4) If OK, disconnect ECM connector.
5) Check for proper connection to ECM at
C42-6 terminal.
6) If OK, check “BLK/RED”, “GRN/RED” and
“BLK” circuit for open and short.
Are they in good condition?Replace IAC valve and
recheck.Repair or replace.
[A] : When using SUZUKI scan tool:[ A]
6B-4 ENGINE COOLING
DIAGNOSIS
DIAGNOSIS TABLE
Condition Possible Cause Correction
Engine overheats
(It is in case that radia-
tor fan operates)Loose or broken water pump belt Adjust or replace.
Not enough coolant Check coolant level and add as
necessary.
Faulty thermostat Replace.
Faulty water pump Replace.
Dirty or bent radiator fins Clean or remedy.
Coolant leakage on cooling system Repair.
Clogged radiator Check and replace radiator as nec-
essary.
Faulty radiator cap Replace.
Improper ignition timing Adjust.
Dragging brakes Adjust brake.
Slipping clutch Adjust or replace.
Poor charge battery Check and replace as necessary.
Poor generation generator Check and repair.
ECT sensor faulty Check and replace as necessary.
Radiator cooling fan relay No.2 and/or No.3
faultyCheck and replace as necessary.
ECM faulty Check and replace as necessary.
Wiring or grounding faulty Repair and necessary.
Equipped with too much electric load part Dismount.
Radiator cooling fan motor faulty Check and replace as necessary.
Engine overheats
(It is in case that radia-
tor fan won’t operates)Fuse blown Check “RADTR fan” fuse and
check for short circuit to ground.
Radiator cooling fan relay No.1 Check and replace as necessary.
ECT sensor faulty Check and replace as necessary.
Radiator cooling fan motor faulty Check and replace as necessary.
Wiring or grounding faulty Repair as necessary
ECM faulty Check and replace as necessary.
ENGINE AND EMISSION CONTROL SYSTEM 6E1-13
ECM TERMINAL ARRANGEMENT TABLE
For TYPE A (Refer to NOTE in page “ECM INPUT/OUTPUT CIRCUIT DIAGRAM” for applicable model.)
CONNEC-
TORTERMINAL WIRE COLOR CIRCUITCONNEC-
TORTERMINAL WIRE COLOR CIRCUIT
C421 BLK/ORN Ground for ECM
C4112––
2 BLK Ground for drive circuit 13–Heated oxygen sensor-2
3 BLK/ORN Ground for drive circuit 14 LT BLU“D”, “2”, “L”-range ID-UP signal
4 BLU/BLK Canister purge valve 15 RED“R”-range signal
5 WHT/BLK Coolant temp. signal output 16 YEL/GRN A/C SW signal
6 GRN/RED IAC valve 17 BRN/YEL EGR valve (stepper motor coil 4)
7 RED/BLU Heater of HO2S-1 18 BLU Radiator fan relay 1
8 BLU/ORN No.4 fuel injector 19 PNK Fuel pump relay
9 BLU/YEL No.1 fuel injector 20––
10 ORN Ground for sensor circuit 21 PPL Throttle opening signal output for A/T
11 RED/YEL CMP sensor 22 YEL/RED Fuel level gauge
12 RED Knock sensor (if equipped) 23 BLK/WHT TCM serial data line
13 WHTHeated oxygen sensor-1
(if equipped)
24––
CO adjusting resistor
(if equipped)
14 LT GRN Coolant temp. sensor
15 LT GRN/BLK Intake air temp. sensor
G021 PPL/WHT Malfunction indicator lamp
16 WHT/GRN Test switch terminal (if equipped) 2 PPL Vehicle speed sensor
17 RED/BLK Electric load (+) 3 PPL/YEL Radiator fan relay 2
18 PNK/GRN A/C switch 4––
19 GRN/WHTIG coil assembly for No.2 and 3 spark
plugs5 BLU Data link connector
20 GRN/YELIG coil assembly for No.1 and 4 spark
plugs6 BLK/WHT Ignition switch signal
21 BLU/WHT No.2 fuel injector 7 YEL Data link connector
22 GRY/RED Power supply for sensor 8––
23 YEL/BLK CKP sensor (+) 9 GRN/WHTStop lamp switch (Brake pedal
switch)
24––10 ORN GND for sensor
25–Ground for sensor shield wire 11––
26 RED/WHT MAP sensor 12 PNKImmobilizer indicator lamp
(if equipped)
27 PPL/WHTDiagnosis switch terminal
(if equipped)13 PNK/BLU Electrical load (-)
28 PNK/BLU Duty output terminal (if equipped) 14 WHT/BLK A/C evaporator temp. sensor
29 BRN Heater of HO2S-2 15––
30 GRN/BLK Heated oxygen sensor-2 16 BRN Tachometer signal
31 BLU/RED No.3 fuel injector 17 WHT/RED Backup power source
C411 PNK/BLK A/C compressor clutch
2 GRN EGR valve (stepper motor coil 1)
3 GRY/BLU Throttle position (TP) sensor
4–Heater of HO2S-2
5 BLK/RED Power source
6 BLK/RED Power source
7 BLK/YEL Engine start signal
8 WHT/RED EGR valve (stepper motor coil 3)
9 GRN/ORN EGR valve (stepper motor coil 2)
10 BRN/WHT Ground for main relay
11––
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
NOTE:
For abbreviation of wire color, refer to Section 0A.
6E1-14 ENGINE AND EMISSION CONTROL SYSTEM
For TYPE B (Refer to NOTE in page “ECM INPUT/OUTPUT CIRCUIT DIAGRAM” for applicable model.)
CONNEC-
TORTERMINAL WIRE COLOR CIRCUITCONNEC-
TORTERMINAL WIRE COLOR CIRCUIT
C421 BLK/ORN Ground for ECM
C4112––
2 BLK Ground for drive circuit 13––
3 BLK/ORN Ground for drive circuit 14 PPL/WHT Diagnosis switch terminal
4 BLU/BLK Canister purge valve 15 WHT/GRN Test switch terminal
5––16 YEL/GRN A/C SW signal
6 GRN/RED IAC valve 17 RED/YEL
Electric load (+)
7 RED/BLU Heater of HO2S-1 18 BLU Radiator fan relay 1
8 BLU/ORN No.4 fuel injector 19 PNK Fuel pump relay
9 BLU/YEL No.1 fuel injector 20 BLK/YEL
Cranking signal
10 ORN Ground for sensor circuit 21 GRN/WHTStop lamp switch (Brake pedal
switch)
11 RED/YEL CMP sensor 22 PPL Vehicle speed sensor
12 Or Grand for shield wire 23––
13 WHTHeated oxygen sensor-1
(if equipped)
24––
CO adjusting resistor
(if equipped)
14 LT GRN Coolant temp. sensor
15 LT GRN/BLK Intake air temp. sensor
G021 WHT/BLK A/C evaporator temp. sensor
16 GRY/BLU Throttle position (TP) sensor 2 RED“R” range signal
17 WHT/RED EGR valve (stepper motor coil 3) 3––
18 GRY EGR valve (stepper motor coil 1) 4––
19 GRN/WHTIG coil assembly for No.2 and 3 spark
plugs5 WHT/BLK Engine coolant temp. signals output
20 GRN/YELIG coil assembly for No.1 and 4 spark
plugs6 GRN/RED“D”, “2”, “L” range ID-UP signal
21 BLU/WHT No.2 fuel injector 7 YEL Data link connector
22 GRY/RED Power supply for sensor 8––
23 YEL/BLK CKP sensor (+) 9 PPL/WHT Malfunction indicator lamp
24––10––
25 RED Knock sensor (if equipped) 11 BLU
Data link connector
26 RED/WHT MAP sensor 12––
27––13 PNK/BLU Electrical load (-)
28 BRN/YEL EGR valve (stepper motor coil 4) 14 ORN Ground for sensor
29 GRN/ORNEGR valve (stepper motor coil 2)
15 PPL
Throttle opening signal output for
A/T
30 PNK/GRN A/C switch 16 BRN Tachometer signal
31 BLU/RED No.3 fuel injector 17––
C411 PNK/BLK A/C compressor clutch
2––
3––
4––
5 BLK/RED Power source for drive circuit
6 BLK/RED Power source for main circuit
7 WHT/RED Power source for memory circuit
8 PNK/BLU Duty signal output terminal
9 GRN/RED Radiator fan drive relay No.2
10 BRN/WHT Ground for main relay
11 BLK/WHT
Ignition switch signal
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
NOTE:
For abbreviation of wire color, refer to Section 0A.