Downloaded from www.Manualslib.com manuals search engine 6-72 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0300 Random Misfire Detected (Misfire Detected at 2 or More Cylinders)
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
CIRCUIT DESCRIPTION
ECM monitors crankshaft revolution speed and engine speed via the crankshaft position sensor and cylinder No.
via the camshaft position sensor. Then it calculates the change in the crankshaft revolution speed and from how
many times such change occurred in every 200 or 1000 engine revolutions, it detects occurrence of misfire.
When ECM detects a misfire (misfire rate per 200 revolutions) which can cause overheat and damage to the
three way catalytic converter, it makes the malfunction indicator lamp (MIL) flash as long as misfire occurs at
that rate.
After that, however, when the misfire rate drops, MIL remains ON until it has been judged as normal 3 times
under the same driving conditions.
Also, when ECM detects a misfire (misfire rate per 1000 revolutions) which will not cause damage to three way
catalytic converter but can cause exhaust emission to be deteriorated, it makes MIL light according to the 2 driv-
ing cycle detection logic.
1. Ignition coil assembly (for No.1 and No.4 cylinder)
2. Ignition coil assembly (for No.2 and No.3 cylinder)
3. Fuel injector
4. CKP sensor
5. CMP sensor
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-73
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) 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. : – 10 – 110 °C, 14 – 230 °F
4) Start engine and keep it at idle for 2 min. or more.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
6) If DTC is not detected at idle, consult usual driving based on information obtained in “Customer complaint
analysis” and “Freeze frame data check”.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
Engine under other than high revolution condition
Not on rough road
Engine speed changing rate (below specified value)
Manifold absolute pressure changing rate (below
specified value)
Throttle opening changing rate (below specified
value)
Misfire rate per 200 or 1000 engine revolutions (how
much and how often crankshaft revolution speed
changes) is higher than specified valueEngine overheating
Vacuum leaks (air inhaling) from air intake system
Ignition system malfunction (spark plug(s), high-
tension cord(s), ignition coil assembly)
Fuel pressure out of specification
Fuel injector malfunction (clogged or leakage)
Engine compression out of specification
Valve lash (clearance) out of specification
Manifold absolute pressure sensor malfunction
Engine coolant temp. sensor malfunction
PCV valve malfunction
EVAP control system malfunction
EGR system malfunction
NOTE:
Among different types of random misfire, if misfire occurs at cylinders 1 and 4 or cylinders 3 and 2
simultaneously, it may not possible to reconfirm DTC by using the following DTC confirmation proce-
dure. When diagnosing the trouble of DTC P0300 (Random misfire detected) of the engine which is
apparently misfiring, even if DTC P0300 cannot be reconfirmed by using the following DTC confirma-
tion procedure, proceed to the following Diag. Flow Table.
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.
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine
Diag. Flow Table”.
2 Is there DTC other than Fuel system (DTC P0171/
P0172) and misfire (DTC P0300 – P0304)?Go to applicable DTC
Diag. Flow Table.Go to Step 3.
Downloaded from www.Manualslib.com manuals search engine 6-74 ENGINE GENERAL INFORMATION AND DIAGNOSIS
3 Check Ignition System.
1) Remove spark plugs and check them for;
Air gap : 1.0 – 1.1 mm (0.040 – 0.043 in.) See Fig. 1.
Carbon deposits / Insulator damage / Plug type
If abnormality is found, adjust, clean or replace by
referring to Section 6F. (See CAUTION)
2) Disconnect all injector connectors. See Fig. 2.
3) Connect spark plugs to high tension cords and then
ground spark plugs.
4) Crank engine and check that each spark plug sparks.
Are above check results satisfactory?Go to Step 4. Check ignition sys-
tem parts (Refer to
Section 6F).
4 Check Fuel Pressure (Refer to Section 6E for details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge. See Fig. 3.
3) Check fuel pressure.
Fuel pressure specification
With fuel pump operating and engine at stop :
270 – 310 kPa, 2.7 – 3.1 kg/cm
2, 38.4 – 44.0 psi.
At specified idle speed :
210 – 260 kPa, 2.1 – 2.6 kg/cm
2, 29.8 – 37.0 psi.
Is measured value as specified?Go to Step 5. Go to Diag. Flow
Table B-3 fuel pres-
sure check.
5 Check Fuel Injectors and Circuit.
1) sing sound scope (1) or such, check operating sound
of each injector (2) when engine is running. Cycle of
operating sound should very according to engine
speed. See Fig 4.
If no sound or an unusual sound is heard, check
injector circuit (wire or coupler) or injector.
2) Turn ignition switch OFF and disconnect a fuel injec-
tor connector.
3) Check for proper connection to fuel injector at each
terminal.
4) If OK, then check injector resistance. See Fig. 5.
Injector resistance
11.3 – 13.8 ohm at 20 °C (68 °F)
5) Carry out steps 1) and 3) on each injector.
6) Check each injector for injected fuel volume referring
to Section 6E. See Fig. 6.
Injected fuel volume
43 – 47 cc/15 sec (1.45/1.51 – 1.58/1.65 US/Imp. oz/
15 sec)
7) Check each injector for fuel leakage after injector
closed.
Fuel leakage
Less than 1 drop/min.
Is check result in step 1) and 3) to 7) satisfactory?Go to Step 6. Check injector cir-
cuit or replace fuel
injector(s).
6 Check PCV valve for clogging (See Section 6E).
Is it in good condition?Go to Step 7. Replace PCV
valve. Step Action Yes No
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-109
[D] Table 1 for Step 3 and 4
Table B-1 Fuel Injector Circuit Check
INSPECTION
Scan tool voltmeter
SUZUKI SCAN TOOL
DISPLAYVOLTAGE AT E17-6
Selector lever
position“P” and “N” range P/N range 10 – 14V
“R”, “D”, “2” and “L” range D range 0 – 1V
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Check Injector for Operating Sound.
Using sound scope, check each injector for
operating sound at engine cranking.
Do all 4 injector make operating sound?Fuel injector circuit is in
good condition.Go to Step 3.
3 Dose none of 4 injectors make operating sound
at Step 2?Go to Step 4. Check coupler connec-
tion and wire harness of
injector not making oper-
ating sound and injector
itself (Refer to Section
6E).
4 Check power circuit of injectors for open and
short.
Is it normal?Check all 4 injectors for
resistance respectively.
If resistance is OK, substi-
tute a known-good ECM
and recheck.Power circuit open or
short.
Downloaded from www.Manualslib.com manuals search engine 6-112 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Table B-3 Fuel Pressure Check
INSPECTION
1. Injector 3. Fuel pump (B) : Hose
2. Delivery pipe (A) : Fuel pressure gauge (C) : Attachment
Step Action Yes No
1 Check Fuel Pressure (Refer to Section 6E for
details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge. See Fig.1.
3) Check fuel pressure by repeating ignition
switch ON and OFF.
Is fuel pressure then 270 – 310 kPa
(2.7 - 3.1 kg/cm
2, 38.4 – 44.0 psi)?Go to Step 2. Go to Step 4.
2
Is 250 kPa (2.5 kg/cm
2, 35.6 psi) or higher fuel
pressure retained for 1 minute after fuel pump is
stopped at Step 1?Normal fuel pressure. Go to Step 3.
3 Is there fuel leakage from fuel feed line hose,
pipe or their joint?Fuel leakage from hose,
pipe or joint.Faulty fuel pressure regu-
lator.
4 Was fuel pressure higher than spec. in Step 1? Faulty fuel pressure regu-
lator.Clogged fuel filter,
Restricted fuel feed hose
or pipe, Faulty fuel pump
or Fuel leakage from hose
connection in fuel tank.
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-123
Special Tool
09912-58441 09912-58431 09912-58490 09912-58421
Pressure gauge Pressure hose 3-way joint & hose Checking tool set
(See NOTE “A”.)
09912-57610 09917-47010 09930-88530 09931-76011
Checking tool plate Vacuum pump gauge Injector test lead SUZUKI scan tool (Tech
1A) kit (See NOTE “B”.)
09931-76030
Mass storage cartridge 16 / 14 pin DLC cable Tech 2 kit (SUZUKI scan
tool) (See NOTE “C”.)
NOTE:
“A” : This kit includes the following items.
1. Tool body & washer, 2. Body plug, 3. Body attachment, 4. Holder, 5. Return hose & clamp,
6. Body attachment-2 & washer, 7. Hose attachment-1, 8. Hose attachment-2
“B” : This kit includes the following items and substitutes for the Tech 2 kit.
1. Storage case, 2. Operator’s manual, 3. Tech 1A, 4. DLC cable, 5. Test lead / probe,
6. Power source cable, 7. DLC cable adaptor, 8. Self–test adaptor
“C” : This kit includes the following items and substitutes for the Tech 1A kit.
1. Tech 2, 2. PCMCIA card, 3. DLC cable, 4. SAE 16/19 adapter, 5. Cigarette cable,
6. DLC loopback adapter, 7. Battery power cable, 8. RS232 cable, 9. RS232 adapter,
10. RS232 loopback connector, 11. Storage case, 12. Power supply
Downloaded from www.Manualslib.com manuals search engine 6A1-4 ENGINE MECHANICAL (M13 ENGINE)
Diagnosis
Diagnosis Table
Refer to “Engine Diagnosis Table” in Section 6.
Compression Check
Check compression pressure on all 4 cylinders as follows:
1) Warm up engine.
2) Stop engine after warming up.
3) Disconnect accelerator cable (1) from clamp (2) (For left
hand steering vehicle only).
4) Remove cylinder head upper cover (3).
5) Disconnect ignition coil couplers (1).
6) Remove ignition coil assemblies (2) with high-tension cord
(3).
7) Remove all spark plugs.
8) Disconnect fuel injector wires (4) at the coupler.
9) Install special tools (Compression gauge) into spark plug
hole.
Special tool
(A) : 09915-64510-001
(B) : 09915-64510-002
(C) : 09915-64530
(D) : 09915-67010 NOTE:
After warming up engine, place transmission gear shift
lever in “Neutral” (shift selector lever to “P” range for A/T
model), and set parking brake and block drive wheels.
Downloaded from www.Manualslib.com manuals search engine ENGINE MECHANICAL (M13 ENGINE) 6A1-5
10) Disengage clutch (1) (to lighten starting load on engine) for
M/T vehicle, and depress accelerator pedal (2) all the way to
make throttle fully open.
11) Crank engine with fully charged battery, and read the highest
pressure on compression gauge.
Compression pressure specification
12) Carry out Steps 9) through 11) on each cylinder to obtain 4
readings.
13) After checking, install spark plugs and ignition coil assem-
blies (1) with high-tension cord (2).
14) Connect ignition coil couplers (3).
15) Connect fuel injector wires (4) at the coupler.
16) Check cylinder head upper cover gasket for deterioration and
then install it into groove of cylinder head upper cover (1)
securely.
17) Install cylinder head upper cover with gasket on to cylinder
head cover.
18) Connect accelerator cable (2) to clamp (3) (For left hand
steering vehicle only).
NOTE:
For measuring compression pressure, crank engine at
least 250 rpm by using fully charged battery.
If check results are below the limit valve, check instal-
lation condition for special tool.
Standard1400 kPa
(14.0 kg/cm
2, 199.0 psi)
Limit1100 kPa
(11.0 kg/cm
2, 156.0 psi)
Max. difference between
any two cylinders100 kPa
(1.0 kg/cm
2, 14.2 psi)