GENERAL INFORMATION 0A-9
Always be careful not to handle electrical parts (computer,
relay, etc.) in a rough manner or drop them.
PRECAUTIONS FOR CATALYTIC CONVERTER
For vehicles equipped with a catalytic converter, use only un-
leaded gasoline and be careful not to let a large amount of un-
burned gasoline enter the converter or it can be damaged.
–Conduct a spark jump test only when necessary, make it as
short as possible, and do not open the throttle.
–Conduct engine compression checks within the shortest
possible time.
–Avoid situations which can result in engine misfire (e.g.
starting the engine when the fuel tank is nearly empty.).
PRECAUTIONS FOR ELECTRICAL CIRCUIT
SERVICE
When replacing a fuse, make sure to use a fuse of the speci-
fied capacity. Use of a fuse with a larger capacity will cause
a damage to the electrical parts and a fire.
When disconnecting and connecting coupler, make sure to
turn ignition switch OFF, or electronic parts may get dam-
aged.
1. Check contact tension by inserting and removing just once
2. Check each terminal for bend and proper alignment
GENERAL INFORMATION 0A-15
INTERMITTENT AND POOR CONNECTION
Most intermittent are caused by faulty electrical connections or wir-
ing, although a sticking relay or solenoid can occasionally be at
fault. When checking it for proper connection, perform careful
check of suspect circuits for:
Poor mating of connector halves, or terminals not fully seated in
the connector body (backed out).
Dirt or corrosion on the terminals. The terminals must be clean
and free of any foreign material which could impede proper termi-
nal contact. However, cleaning the terminal with a sand paper or
the like is prohibited.
Damaged connector body, exposing the terminals to moisture
and dirt, as well as not maintaining proper terminal orientation
with the component or mating connector.
Improperly formed or damaged terminals.
Check each connector terminal in problem circuits carefully to en-
sure good contact tension by using the corresponding mating ter-
minal.
If contact tension is not enough, reform it to increase contact ten-
sion or replace.
Poor terminal-to-wire connection.
Check each wire harness in problem circuits for poor connection
by shaking it by hand lightly. If any abnormal condition is found,
repair or replace.
Wire insulation which is rubbed through, causing an intermittent
short as the bare area touches other wiring or parts of the vehicle.
Wiring broken inside the insulation. This condition could cause
continuity check to show a good circuit, but if only 1 or 2 strands
of a multi-strand-type wire are intact, resistance could be far too
high.
If any abnormality is found, repair or replace.
HOSE CONNECTION
Clamp securely at a position 3 to
7mm (0.12–0.27 in.) from hose end. With short pipe, fit hose as far as it reaches pipe joint as
shown.
Hose
Pipe
ClampClamps securely at a position
3 to 7 mm (0.12–0.27 in.)
from hose end.
With following type pipe, fit hose as far as its peripheral
projection as shown.
Clamp securely at a position
3 to 7 mm (0.12–0.27 in.)
from hose end.
With bent pipe, fit hose as its bent part as shown or till pipe
is about 20 to 30 mm (0.79–1.18 in.) into the hose.
Clamp securely at a
position 3 to 7 mm
(0.12–0.27 in.) from hose
end.
With straight pipe, fit hose till pipe is, about 20 to 30 mm
(0.79–1.18 in.) into the hose.
Hose
20 to 30 mm
(0.79–1.18 in.)
Clamp
6-4 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
PRECAUTION ON FUEL SYSTEM SERVICE
Work must be done with no smoking, in a well-ventilated area and
away from any open flames.
As fuel feed line (between fuel pump and fuel delivery pipe) is still
under high fuel pressure even after engine was stopped, loosen-
ing or disconnecting fuel feed line directly may cause dangerous
spout of fuel to occur where loosened or disconnected.
Before loosening or disconnecting fuel feed line, make sure to re-
lease fuel pressure according to “FUEL PRESSURE RELIEF
PROCEDURE”. A small amount of fuel may be released after the
fuel line is disconnected. In order to reduce the chance of person-
al injury, cover the fitting to be disconnected with a shop cloth. Put
that cloth in an approved container when disconnection is com-
pleted.
Never run engine with fuel pump relay disconnected when engine
and exhaust system are hot.
Fuel or fuel vapor hose connection varies with each type of pipe.
When reconnecting fuel or fuel vapor hose, be sure to connect
and clamp each hose correctly referring to left figure Hose Con-
nection.
After connecting, make sure that it has no twist or kink.
When installing injector or fuel delivery pipe, lubricate its O-ring
with spindle oil or gasoline.
When connecting fuel pipe flare nut, first tighten flare nut by hand
and then tighten it to specified torque.
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.
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
6-30 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
SCAN TOOL DATACONDITIONNORMAL CONDITION /
REFERENCE VALUES
DESIRED IDLEAt idling with no load after warming up, M / T850 r / min(DESIRED IDLE SPEED)
gg,
at neutral, A / T at “P” range850 r / min
TP SENSOR VOLT
(THROTTLE POSITIONIgnition switch
ON / engine
Throttle valve fully closedMore than 0.2 V(
SENSOR OUTPUT
VOLTAGE)ON / engine
stoppedThrottle valve fully openLess than 4.8 V
INJ PULSE WIDTH
(FUEL INJECTIONAt specified idle speed with no load after
warming up0.8 – 2.3 msec.(
PULSE WIDTH)At 2500 r / min with no load after warming up0.8 – 2.3 msec.
IAC FLOW DUTY (IDLE
AIR CONTROL FLOW
DUTY)
At idling with no load after warming up20 – 40%
TOTAL FUEL TRIMAt specified idle speed after warming up–35 – +35%
BATTERY VOLTAGEIgnition switch ON / engine stop10 – 14 V
CANIST PRG DUTY
(EVAP CANISTER
PURGE FLOW DUTY)
At specified idle speed after warming up0 – 100%
CLOSED THROT POS
(CLOSED THROTTLEThrottle valve at idle positionON(CLOSED THROTTLE
POSITION)Throttle valve opens larger than idle positionOFF
FUEL CUTWhen engine is at fuel cut conditionONFUEL CUTOther than fuel cut conditionOFF
RAD FAN
(RADIATOR FANIgnition switch
ON
Engine coolant temp.:
Lower than 92.5C
(199F)
OFF
(
CONTROL RELAY)ONEngine coolant temp.:
97.5C (208F) or higherON
ELECTRIC LOAD
Ignition switch ON / Headlight, small light,
heater fan and rear window defogger all
turned OFF
OFF
ELECTRIC LOADIgnition switch ON / Headlight, small light,
heater fan or rear window defogger turned
ON
ON
A / C SWITCH
Engine running after warming up, A / C not
operatingOFF
A/C SWITCHEngine running after warming up, A / C
operatingON
PSP SWITCH
Engine running at idle speed and steering wheel
at straight-ahead position.OFF
(if equipped).Engine running at idle speed and steering wheel
turned to the right or left as far as it stops.ON
FUEL TANK LEVEL––––––––––––0 – 100%
BAROMETRIC PRESS––––––––––––Display the barometric pressure
FUEL PUMP
Within 3 seconds after ignition switch ON or
engine runningON
Engine stop at ignition switch ON.OFF
6-32 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
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 (PCM)
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 us-
ing 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 val-
ue of 0 indicates 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 correc-
tions to the air / fuel mixture computation. A value of 0
indicates no correction, a value greater than 0 means
an enrichment correction, and a value less than 0 im-
plies 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.
IGNITION ADVANCE
(IGNITION TIMING ADVANCE FOR NO.1
CYLINDER, )
Ignition timing of NO.1 cylinder is commanded by
ECM (PCM). The actual ignition timing should be
checked by using the timing light.
INTAKE AIR TEMP. (C, F)
It is detected by intake air temp. sensor and used to
determine the amount of air passing into the intake
manifold as air density varies with temperature.
MAF (MASS AIR FLOW RATE, gm / s, lb / min)
It represents total mass of air entering intake manifold
which is computed based on signals from MAP sen-
sor, IAT sensor, TP sensor, etc.
THROTTLE POS
(ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is fully closed position,
throttle opening is indicated as 0% and 100% full open
position.
OXYGEN SENSOR B1 S1
(HEATED OXYGEN SENSOR-1, V)
It indicates output voltage of HO2S-1 installed on ex-
haust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2
(HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on ex-
haust pipe (post-catalyst). It is used to detect catalyst
deterioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM (PCM) internal pa-
rameter which indicates the ECM (PCM) requested
idle. If the engine is not running, this number is not valid.
TP SENSOR VOLT (THROTTLE POSITION
SENSOR OUTPUT VOLTAGE, V)
The Throttle Position Sensor reading provides throttle
valve opening information in the form of voltage.
INJ PULSE WIDTH
(FUEL INJECTION PULSE WIDTH, msec.)
This parameter indicates time of the injector drive
(valve opening) pulse which is output from ECM
(PCM) (but injector drive time of NO.1 cylinder for
multiport fuel injection).
IAC FLOW DUTY (IDLE AIR (SPEED) CONTROL
DUTY, %)
This parameter indicates opening of the throttle valve
in terms of percentage to opening controllable by the
ISC actuator.
TOTAL FUEL TRIM (%)
The value of Total Fuel Trim is obtained by putting val-
ues of short Term Fuel Trim and Long Term Fuel Trim
together. This value indicates how much correction is
necessary to keep the air / fuel mixture stoichiomet-
rical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage in-
putted from main relay to ECM (PCM).