ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-5
FUEL PRESSURE RELIEF PROCEDURE
CAUTION:
This work must not be done when engine is hot. If done so,
it may cause adverse effect to catalyst.
After making sure that engine is cold, release fuel pressure as fol-
lows.
1) Place transmission gear shift lever in “Neutral” (Shift selector le-
ver to “P” range for A / T model), set parking brake, and block
drive wheels.
2) Remove relay box cover.
3) Disconnect fuel pump relay (1) from relay box (2).
4) Remove fuel filler cap to release fuel vapor pressure in fuel tank
and then reinstall it.
5) Start engine and run it till it stops for lack of fuel. Repeat cranking
engine 2-3 times for about 3 seconds each time to dissipate fuel
pressure in lines. Fuel connections are now safe for servicing.
6) Upon completion of servicing, connect fuel pump relay to relay
box and install relay box cover.
FUEL LEAKAGE CHECK PROCEDURE
After performing any service on fuel system, check to make sure
that there are no fuel leakages as follows.
1) Turn ON ignition switch for 2 seconds (to operate fuel pump) and
then turn it OFF.
Repeat this (ON and OFF) 3 or 4 times and apply fuel pressure
to fuel line. (till fuel pressure is felt by hand placed on fuel feed
hose.)
2) In this state, check to see that there are no fuel leakages from
any part of fuel system.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-9
PRECAUTION IN DIAGNOSING TROUBLE
Don’t disconnect couplers from ECM (PCM), battery cable from
battery, ECM (PCM) ground wire harness from engine or main
fuse before confirming diagnostic information (DTC, freeze frame
data, etc.) stored in ECM (PCM) memory. Such disconnection will
erase memorized information in ECM (PCM) memory.
Diagnostic information stored in ECM (PCM) memory can be
cleared as well as checked by using SUZUKI scan tool (Tech-1)
or generic scan tool. Before using scan tool, read its Operator’s
(Instruction) Manual carefully to have good understanding as to
what functions are available and how to use it.
Priorities for diagnosing troubles.
If two or more DTCs are stored, proceed to the flow table of the
DTC which has detected earliest in the order and follow the
instruction in that table.
If no instructions are given, troubleshoot diagnostic trouble codes
according to the following priorities.
1. Diagnostic trouble codes (DTCs) other than DTC P0171 /
P0172 (Fuel system too lean / too rich) and DTC P0300 /
P0301 / P0302 / P0303 (Misfire detected)
2. DTC P0171 / P0172 (Fuel system too lean / too rich)
3. DTC P0300 / P0301 / P0302 / P0303 (Misfire detected)
Be sure to read “Precautions for Electrical Circuit Service” in Sec-
tion 0A before inspection and observe what is written there.
ECM (PCM) Replacement
When substituting a known-good ECM (PCM), check for following
conditions. Neglecting this check may cause damage to a known-
good ECM (PCM).
–Resistance value of all relays, actuators is as specified respec-
tively.
–MAP sensor and TP sensor are in good condition and none of
power circuits of these sensors is shorted to ground.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-13
MALFUNCTION INDICATOR LAMP (MIL)
CHECK
1) Turn ON ignition switch (but the engine at stop) and check that
MIL lights.
If MIL does not light up (or MIL dims), go to “Diagnostic Flow
Table A-1” for troubleshooting.
2) Start engine and check that MIL turns OFF.
If MIL remains ON and no DTC is stored in ECM (PCM), go to
“Diagnostic Flow Table A-2” for troubleshooting.
DIAGNOSTIC TROUBLE CODE (DTC) CHECK
1) Prepare SUZUKI scan tool (Tech-1) or generic scan tool.
2) With ignition switch OFF, connect it to data link connector (DLC)
(1) located on underside of instrument panel at driver’s seat side.
Special Tool:
(A): SUZUKI scan tool
(B): Mass storage cartridge
(C): 16 / 14 pin DLC cable
3) Turn ignition switch ON and confirm that MIL lights.
4) Read DTC, pending DTC and freeze frame data according to
instructions displayed on scan tool and print it or write it down.
Refer to scan tool operator’s manual for further details.
If communication between scan tool and ECM (PCM) is not pos-
sible, check if scan tool is communicable by connecting it to
ECM (PCM) in another vehicle. If communication is possible in
this case, scan tool is in good condition. Then check data link
connector and serial data line (circuit) in the vehicle with which
communication was not possible.
5) After completing the check, turn ignition switch off and discon-
nect scan tool from data link connector.
6-14 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DIAGNOSTIC TROUBLE CODE (DTC)
CLEARANCE
1) Connect SUZUKI scan tool (Tech-1) or generic scan tool to data
link connector in the same manner as when making this connec-
tion for DTC check.
2) Turn ignition switch ON.
3) Erase DTC and pending DTC according to instructions dis-
played on scan tool. Refer to scan tool operator’s manual for fur-
ther details.
4) After completing the clearance, turn ignition switch off and dis-
connect scan tool from data link connector.
NOTE:
DTC and freeze frame data stored in ECM (PCM) memory
are also cleared in following cases. Be careful not to clear
them before keeping their record.
When power to ECM (PCM) is cut off (by disconnecting
battery cable, removing fuse or disconnecting ECM
(PCM) connectors for 30 sec. or longer)
When the same malfunction (DTC) is not detected again
during 40 engine warm-up cycles.
6-16 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC
NO.DETECTING ITEMDETECTING CONDITION
(DTC will set when detecting:)MIL
P0335Crankshaft position sensor
circuit malfunctionNo signal during engine running1 driving cycle
P0340Camshaft position sensor
circuit malfunctionNo signal for 2 sec. during engine cranking1 driving cycle
P0420Catalyst system efficiency
below threshold
Output waveforms of HO2S-1 and HO2S-2
are similar.
(Time from output voltage change of HO2S-1
to that of HO2S-2 is shorter than
specification.)
2 driving cycles
P0443EVAP Purge control valve
circuit malfunctionPurge control valve circuit is open or shorted
to ground2 driving cycles
P0480Radiator fan control circuit
malfunctionRadiator cooling fan relay terminal voltage is
low when cooling temp. is lower than
specification
2 driving cycles
P0500Vehicle speed sensor
malfunctionNo signal while running in “D” range or during
fuel cut at decelerating2 driving cycles
P0505Idle control system malfunction
Throttle opening change is small as compared
with electrically live time. Throttle valve opening
is not within its target range with CTP switch ON
or drive voltage exists though ECM (PCM) is not
outputting ISC drive command.
1 driving cycle
P0510Closed throttle position switch
malfunctionSwitch does not change from ON to OFF
(or from OFF to ON) even when vehicle speed
reaches over (or below) specification.
2 driving cycle
P1250Early Fuel Evaporation Heater
Circuit MalfunctionHeater monitor terminal voltage is higher than
specified value when EFE OFF or it is lower
than specified value when EFE ON.
2 driving cycles
P1450Barometric pressure sensor
circuit malfunctionBarometric pressure is lower or higher than
specification. (or sensor malfunction)1 driving cycle
P1451Barometric pressure sensor
performance problem
Difference between manifold absolute
pressure (MAP sensor value) and
barometric pressure (barometric pressure
sensor value) is larger than specification
during cranking.
2 driving cycles
P1500Starter signal circuit
malfunctionStarter signal is not inputted from engine
cranking till its start and after or it is always
inputted
2 driving cycles
P1510ECM (PCM) backup power
source malfunctionNo backup power after starting engine1 driving cycle
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-19
Operation
VISUAL INSPECTION
Visually check following parts and systems.
INSPECTION ITEM
REFERRING SECTION
Engine oil ––––– level, leakage
Engine coolant ––––– level, leakage
Fuel ––––– level, leakage
A / T fluid ––––– level, leakage
Air cleaner element ––––– dirt, clogging
Battery ––––– fluid level, corrosion of terminal
Water pump belt ––––– tension, damage
Throttle cable ––––– play, installation
Vacuum hoses of air intake system ––––– disconnection,
looseness, deterioration, bend
Connectors of electric wire harness ––––– disconnection, friction
Fuses ––––– burning
Parts ––––– installation, bolt ––––– looseness
Parts ––––– deformation
Other parts that can be checked visually
Also check following items at engine start, if possible
Malfunction indicator lamp
Charge warning lamp
Engine oil pressure warning lamp
Engine coolant temp. meter
Fuel level meter
Tachometer, if equipped
Abnormal air being inhaled from air intake system
Exhaust system ––––– leakage of exhaust gas, noise
Other parts that can be checked visuallySection 0B
Section 0B
Section 0B
Section 0B
Section 0B
Section 0B
Section 6E1
Section 8
Section 6
Section 6H
Section 8 (section 6 for pressure check)
Section 8
Section 8
6-20 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
ENGINE BASIC INSPECTION
This check is very important for troubleshooting when ECM (PCM) has detected no DTC and no abnormality has
been found in visual inspection.
Follow the flow table carefully.
STEP
ACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check battery voltage.
Is it 11 V or more?Go to Step 3.Charge or replace
battery.
3Is engine cranked?Go to Step 4.Go to “DIAGNOSIS”
in Section 6G.
4Does engine start?Go to Step 5.Go to Step 7.
5Check idle speed as follows.
1) Warm up engine to normal operating temp.
2) Shift transmission to neutral position for M / T
(“P” position for A / T).
3) All of electrical loads are switched off.
4) Check engine idle speed with scan tool.
See Fig. 1.
Is it 800 – 900 r / min.?Go to Step 6.Go to “ENGINE
DIAGNOSIS TABLE”.
6Check ignition timing as follows.
1) Select “MISC” mode on SUZUKI scan tool and
fix ignition timing to initial one. See Fig. 2.
2) Using timing light (1), check initial ignition timing.
See Fig. 3.
Is it 5 ± 3 BTDC at specified idle speed?Go to “ENGINE
DIAGNOSIS TABLE”.Check ignition control
related parts referring
to Section 6F.
7Check immobilizer system malfunction as follows.
1) Check immobilizer indicator lamp for flashing.
Is it flashing when ignition switch is turned to ON
position?Go to “DIAGNOSIS” in
Section 8A.Go to Step 8.
8Check fuel supply as follows.
1) Check to make sure that enough fuel is filled in fuel
tank.
2) Turn ON ignition switch for 2 seconds and then
OFF. See Fig. 4.
Is fuel return pressure (returning sounds) felt from fuel
feed hose (1) when ignition switch is turned ON?Go to Step 10.Go to Step 9.
9Check fuel pump for operating.
1) Was fuel pump operating sound heard from fuel
filler for about 2 seconds after ignition switch ON
and stop?Go to “DIAG. FLOW
TABLE B-3”.Go to “DIAG. FLOW
TABLE B-2”.
10Check ignition spark as follows.
1) Disconnect injector coupler.
2) Remove spark plugs and connect them to high
tension cords.
3) Ground spark plugs.
4) Crank engine and check if each spark plug sparks.
Is it in good condition?Go to Step 11.Go to “DIAGNOSIS”
in Section 6F.
11Check fuel injector for operation as follows.
1) Install spark plugs and connect injector
connectors.
2) Check that fuel is injected out in conical shape
from fuel injector when cranking.
Is it in good condition?Go to “ENGINE
DIAGNOSIS TABLE”.Go to “DIAG. FLOW
TABLE B-1”.
Select “DATA
LIST” modeSELECT MENU
F4: MISC TEST
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-21
Fig. 1 for Step 5 Fig. 2 for Step 6 Fig. 3 for Step 6
Fig. 4 for Step 8 Fig. 5 for Step 11