ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-5
Fuel Pressure Relief Procedure
After making sure that engine is cold, relief fuel pressure as fol-
lows.
1) Place transmission gear shift lever in “Neutral” (shift selector
lever to “P” range for A/T vehicle), set parking brake, and
block drive wheels.
2) Remove fuel pump relay (1) from its connector.
3) Remove fuel filler cap to release fuel vapor pressure in fuel
tank and then reinstall it.
4) Start engine and run it till it stops for lack of fuel. Repeat
cranking engine 2 – 3 times of about 3 seconds each time to
dissipate fuel pressure in lines. Fuel connections are now
safe for servicing.
5) Upon completion of servicing, install fuel pump relay to relay
box.
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 3 seconds (to operate fuel pump)
and then turn it OFF.
Repeat this (ON and OFF) 3 or 4 times and apply fuel pres-
sure to fuel line (till fuel pressure is felt by hand placed on
fuel return hose).
2) In this state, check to see that there are no fuel leakages
from any part of fuel system. CAUTION:
This work must not be done when engine is hot. If done
so, it may cause adverse effect to catalyst.
[A] : Left hand steering vehicle
[B] : Right hand steering vehicle
2. Fuse box
6-1-6 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Engine Diagnosis
General Description
This vehicle is equipped with an engine and emission control system which are under control of ECM (PCM).
The engine and emission control system in this vehicle are controlled by ECM (PCM). ECM (PCM) has an On-
Board Diagnostic system which detects a malfunction in this system and abnormality of those parts that influ-
ence the engine exhaust emission. When diagnosing engine troubles, be sure to have full understanding of the
outline of “ON-BOARD DIAGNOSTIC SYSTEM” and each item in “PRECAUTION IN DIAGNOSING TROUBLE”
and execute diagnosis according to “ENGINE DIAGNOSTIC FLOW TABLE” in this section.
There is a close relationship between the engine mechanical, engine cooling system, ignition system, exhaust
system, etc. and the engine and emission control system in their structure and operation. In case of an engine
trouble, even when the malfunction indicator lamp (MIL) doesn’t turn ON, it should be diagnosed according to
“ENGINE DIAGNOSTIC FLOW TABLE” in this section.
On-Board Diagnostic System (Vehicle without
Monitor Connector)
ECM (PCM) in this vehicle has following functions.
When the ignition switch is turned ON with the engine at a
stop, malfunction indicator lamp (MIL) (1) turns ON to check
the bulb of the malfunction indicator lamp (1).
When ECM detects a malfunction which gives an adverse
effect to vehicle emission while the engine is running, it
makes the malfunction indicator lamp (1) in the meter cluster
of the instrument panel turn ON or flash (flashing only when
detecting a misfire which can cause damage to the catalyst)
and stores the malfunction area in its memory.
(If it detects that continuously 3 driving cycles are normal
after detecting a malfunction, however, it makes MIL (1) turn
OFF although DTC stored in its memory will remain.)
As a condition for detecting a malfunction in some areas in
the system being monitored by ECM (PCM) and turning ON
the malfunction indicator lamp (1) due to that malfunction, 2
driving cycle detection logic is adopted to prevent erroneous
detection.
When a malfunction is detected, engine and driving condi-
tions then are stored in ECM (PCM) memory as freeze frame
data. (For the details, refer to description on Freeze frame
data.)
It is possible to communicate by using not only SUZUKI scan
tool (2) but also generic scan tool. (Diagnostic information
can be accessed by using a scan tool.)
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-9
On-Board Diagnostic System (Vehicle with
Monitor Connector)
ECM diagnosis troubles which may occur in the area including the
following parts when the ignition switch is ON and the engine is
running, and indicates the result by turning on of flashing mal-
function indicator lamp (1).
• Heated oxygen sensor (if equipped)
•ECT sensor
•TP sensor
• IAT sensor
• CMP sensor
•MAF sensor
• Knock sensor
• EGR (if equipped)
•VSS
• CPU (Central Processing Unit) of ECM
ECM and malfunction indicator lamp (1) operate as follows.
• Malfunction indicator lamp (1) light when the ignition switch
is turned ON (but the engine at stop) with the diagnosis
switch terminal ungrounded regardless of the condition of
Engine and Emission control system. This is only to check
the malfunction indicator lamp (1) bulb and its circuit.
• If the above areas of Engine and Emission control system is
free from any trouble after the engine start (while engine is
running), malfunction indicator lamp (1) turns OFF.
• When ECM detects a trouble which has occurred in the
above areas, it makes malfunction indicator lamp (1) turn ON
while the engine is running to warn the driver of such occur-
rence of trouble and at the same time it stores the trouble
area in ECM back-up memory. (The memory is kept as it is
even if the trouble was only temporary and disappeared
immediately. And it is not erased unless the power to ECM is
shut off for specified time.)
ECM also indicates trouble area in memory by means of
flashing of malfunction indicator lamp (1) at the time of
inspection. (i.e. when diagnosis switch terminal (2) is con-
nected to ground terminal (3) with a service wire and ignition
switch is turned ON.)
NOTE:
When a trouble occurs in the above areas and disappears
soon while the diagnosis switch terminal is ungrounded
and the engine is running, malfunction indicator lamp (1)
lights and remains ON as the trouble exists but it turns
OFF when the normal condition is restored.
6-1-14 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
STEP 6. AND 7. RECHECKING AND RECORD OF DTC
Refer to “DTC Check” in this section for checking procedure.
STEP 8. ENGINE BASIC INSPECTION AND ENGINE DIAGNOSIS TABLE
Perform basic engine check according to the “ENGINE BASIC INSPECTION FLOW TABLE” first. When the end
of the flow table has been reached, check the parts of the system suspected as a possible cause referring to
“ENGINE DIAGNOSIS TABLE” and based on symptoms appearing on the vehicle (symptoms obtained through
steps of customer complaint analysis, trouble symptom confirmation and/or basic engine check) and repair or
replace faulty parts, if any.
Engine Basic Inspection Flow Table
Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE” in this
section.
2 Check battery voltage.
Is it 11 V or more?Go to Step 3. Charge or replace battery.
3 Is engine cranked? Go to Step 4. Go to “DIAGNOSIS” in
Section 6H.
4 Does engine start? Go to Step 5. Go to Step 7.
5 Check engine idle speed/IAC duty referring to
“IDLE SPEED/IAC DUTY INSPECTION” in
Section 6E2.
Is check result as specified?Go to Step 6. Go to “ENGINE DIAGNO-
SIS TABLE” in this sec-
tion.
6 Check ignition timing referring to “IGNITION
TIMING INSPECTION” in Section 6F2.
Is check result as specified?Go to “ENGINE DIAGNO-
SIS TABLE” in this sec-
tion.Adjust ignition timing.
7 Check fuel supply as follows :
1) Check to make sure that enough fuel is
filled in fuel tank.
2) Turn ON ignition switch for 3 seconds and
then OFF.
Repeat this a few times.
Is fuel return pressure (returning sounds) felt
from fuel return hose when ignition switch is
turned ON?Go to Step 9. Go to Step 8.
8 Check fuel pump for operating.
1) Was fuel pump operating sound heard from
fuel filler for about 3 seconds after ignition
switch ON and stop?Go to “DIAG. FLOW
TABLE B-3” in this sec-
tion.Go to “DIAG. FLOW
TABLE B-1” in this sec-
tion.
9 Check ignition spark referring to “IGNITION
SPARK TEST” in Section 6E2.
Is it in good condition?Go to Step 10. Go to “DIAGNOSIS” in
Section 6F2.
10 Check fuel injector referring to “Fuel INJECTOR
INSPECTION” in Section 6E2.
Is it in good condition?Go to “ENGINE DIAGNO-
SIS TABLE” in this sec-
tion.Go to “DIAG. FLOW
TABLE B-2” in this sec-
tion.
6-1-16 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Malfunction Indicator Lamp (MIL) Check
1) Turn ON ignition switch (but the engine at stop) and check
that MIL (1) lights.
If MIL does not light up, go to “Diagnostic Flow Table A-1” for
troubleshooting.
2) Start engine and check that MIL turns OFF.
3) 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
[Using SUZUKI scan tool]
1) Prepare generic scan tool or SUZUKI scan tool (2).
2) With ignition switch OFF, connect it to data link connector
(DLC) (3) located on underside of instrument panel at
driver’s seat side.
Special tool
(A) : SUZUKI scan tool
3) Turn ignition switch ON and confirm that MIL lights.
4) Read DTC and freeze frame data according to instructions
displayed on scan tool and print them or write them down.
Refer to scan tool operator’s manual for further details.
If communication between scan tool and ECM (PCM) is not
possible, check if scan tool is communicable by connecting it
to ECM (PCM) in another vehicle. If communication is possi-
ble 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 dis-
connect scan tool from data link connector.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-17
[Without Using SUZUKI Scan Tool] (Vehicle with Monitor
Connector)
1) Check malfunction indicator lamp referring to “Malfunction
Indicator Lamp Check” in this section.
2) With the ignition switch OFF position, disconnect SUZUKI
scan tool if connected and using service wire (4), connect
diagnosis switch terminal (1) to ground terminal (2) in moni-
tor connector (3).
3) With the ignition switch ON position and leaving engine OFF,
read DTC from flashing pattern of malfunction indicator
lamp. Refer to “Diagnostic Trouble Code Table”.
If lamp remains ON, go to “Diagnostic Flow Table A-4”.
4) After completing the check, turn the ignition switch OFF posi-
tion and disconnect service wire from monitor coupler.
Diagnostic Trouble Code (DTC) Clearance
[Using scan tool]
1) With ignition switch OFF, connect generic scan tool or
SUZUKI scan tool to data link connector (DLC).
2) Turn ignition switch ON.
3) Erase DTC according to instructions displayed on scan tool.
Freeze frame data is cleared with the DTC. Refer to scan tool
operator’s manual for further details.
4) After completing the clearance, turn ignition switch off and
disconnect scan tool from data link connector. NOTE:
If abnormality or malfunction lies in two or more areas,
malfunction indicator lamp indicates applicable codes
three times each.
And flashing of these codes is repeated as long as
diagnosis terminal is grounded and ignition switch is
held at ON position.
Take a note of diagnostic trouble code indicated first.
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)
When the same malfunction (DTC) is not detected
again during 40 engine warm-up cycles (refer to
“WARM-UP CYCLE” of “ON-BOARD DIAGNOSTIC SYS-
TEM” in this section) (Vehicle without monitor connec-
tor)
6-1-18 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
[Without using scan tool]
1) Turn the ignition switch OFF position.
2) Disconnect battery negative cable for specified time below to
erase diagnostic trouble code stored in ECM memory and
reconnect it.
Time required to erase DTC:
Diagnostic Trouble Code (DTC) Table
Ambient
temperatureTime to cut power to ECM
Over 0°C (32°F) 30 sec. or longer
Under 0°C
(32°F)Not specifiable.
Select a place with higher than 0°C
(32°F) temperature.
DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without
monitor
connector)MIL
(vehicle
with
monitor
connector)
P0100
(No.34)
Mass air flow circuit malfunc-
tionSensor output too low
1 driving
cycle1 driving
cycle
P0100
(No.33)Sensor output too high
P0110
(No.25)
Intake air temp. circuit mal-
functionIntake air temp. circuit low input
1 driving
cycle1 driving
cycle
P0110
(No.23)Intake air temp. circuit high input
P0115
(No.15)
Engine coolant temp. circuit
malfunctionEngine coolant temp. circuit low input
1 driving
cycle1 driving
cycle
P0115
(No.14)Engine coolant temp. circuit high input
P0120
(No.22)
Throttle position circuit mal-
functionThrottle position circuit low input
1 driving
cycle1 driving
cycle
P0120
(No.21)Throttle position circuit high input
P0121Throttle position circuit perfor-
mance problemPoor performance of TP sensor2 driving
cyclesNot
applicable
*P0130HO2S circuit malfunction
(Bank 1 - Sensor 1)Min. output voltage of HO2S-1 is
higher than specification.
2 driving
cyclesNot
applicable Min. output voltage of HO2S-1 is
lower than specification.
Output voltage of HO2S-1 fails to go
above specification.
**P0130
(No.13)HO2S (Bank 1 - Sensor 1) no
activity detectedOutput voltage of HO2S-1 fails to go
above specification (or HO2S-1 cir-
cuit open).2 driving
cycles2 driving
cycles
6-1-24 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
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 output from ECM (PCM) as
Commands and there may be cases where the engine or actuator is not operating (in the condition) as indicated
by the scan tool. Be sure to use the timing light to check the ignition timing referring to Section 6F2.
NOTE:
For asterisk (
✱) marked item in “OTHER” column, item can be read only SUZUKI scan tool.
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 CONDITIONNORMAL CONDITION/
REFERENCE VALUEOTHER
COOLANT TEMP.
(Engine Coolant Temp.)At specified idle speed after warming up 80 – 100 °C
(176 – 212 °F)
INTAKE AIR TEMP. At specified idle speed after warming up Environmental temp.
+20 °C (+36 °F)
–5 °C (–9 °F)
DESIRE IDLE
(Desired idle speed)At idling with no load after warming up
700 rpm✱
CLOSED THROT POS
(Closed Throttle Position)With ignition switch ON, accelerator pedal
releasedON
✱
With ignition switch ON, accelerator pedal
depressedOFF
IAC FLOW DUTY At specified idle speed after warming up 5 – 40 %✱
ENGINE SPEED At idling with no load after warming up Desired idle speed
± 50 rpm
SHORT FT B1
(Short term fuel trim)At specified idle speed after warming up
–15 ~ +15 %
SHORT FT B2
(Short term fuel trim)At specified idle speed after warming up
–15 ~ +15 %
LONG FT B1
(Long term fuel trim)At specified idle speed after warming up
–15 ~ +15 %
LONG FT B2
(Long term full trim)At specified idle speed after warning up
–15 ~ +15 %
IGNITION ADVANCE At specified idle speed with no load after
warming up6 – 17°
BATTERY VOLTAGE Ignition switch ON/engine stopped 10 – 14 V✱
MAF (Mass Air Flow
Rate)At specified idle speed with no load after
warming up.2.6 – 4.5 g/s
0.34 – 0.59 lb/min
At 2500 r/min with no load after warming up. 10 – 16 g/s
1.32 – 2.11 lb/min
INJ PULSE WIDTH B1
(Fuel Injection Pulse
Width)At specified idle speed with no load after
warming up.2.0 – 3.3 msec
✱
At 2500 r/min with no load after warming up. 2.2 – 3.2 msec