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) 6-1-7
WARM-UP CYCLE
A warm-up cycle means sufficient vehicle operation such that the
coolant temperature has risen by at least 22°C (40°F) from
engine starting and reaches a minimum temperature of 70 °C
(160 °F).
DRIVING CYCLE
A “Driving Cycle” consists of engine startup, driving mode where
a malfunction would be detected if present and engine shutoff.
2 DRIVING CYCLE DETECTION LOGIC
The malfunction detected in the first driving cycle is stored in
ECM (PCM) memory (in the form of pending DTC) but the mal-
function indicator lamp does not light at this time. It lights up at the
second detection of same malfunction also in the next driving
cycle.
PENDING DTC
Pending DTC means a DTC detected and stored temporarily at 1
driving cycle of the DTC which is detected in the 2 driving cycle
detection logic.
FREEZE FRAME DATA
ECM (PCM) stores the engine and driving conditions (in the form
of data as shown in the figure) at the moment of the detection of a
malfunction in its memory. This data is called “Freeze frame data”.
Therefore, it is possible to know engine and driving conditions
(e.g., whether the engine was warm or not, where the vehicle was
running or stopped, where air/fuel mixture was lean or rich) when
a malfunction was detected by checking the freeze frame data.
Also, ECM (PCM) has a function to store each freeze frame data
for three different malfunctions in the order as the malfunction is
detected. Utilizing this function, it is possible to know the order of
malfunctions that have been detected. Its use is helpful when
rechecking or diagnosing a trouble.
1. 1st, 2nd or 3rd in parentheses here represents which position in the
order the malfunction is detected.
1. TROUBLE CODE
2. COOLANT TEMP.
3. ENGINE SPEED
4. SHORT FT B1
5. SHORT FT B2
6. LONG FT B1
7. LONG FT B2
8. CALC LOAD
9. FUEL SYSTEM B1
10. FUEL SYSTEM B2
11. MAP
12. VEHICLE SPEEDP0100
80 C
750 RPM
– 0.8
– 0.1
– 1.3
– 1.5
20.5
CLOSED
CLOSED
30.6 kPa
0 km/h(1st)
1
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.
6-1-10 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DATA LINK CONNECTOR (DLC)
DLC (1) is in compliance with SAEJ1962 in its installation posi-
tion, the shape of connector and pin assignment.
K line of ISO 9141 is used for SUZUKI scan tool to communicate
with ECM (PCM), ABS control module and air bag SDM. SUZUKI
serial data line is used for SUZUKI scan tool to communicate with
Immobilizer control module.
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 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 (Vehicle without monitor connector)
If two or more diagnostic trouble codes (DTCs) are stored, proceed to the flow table of the DTC which was
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.
– Diagnostic trouble codes (DTCs) other than DTC P0171/P0172/P0174/P0175 (Fuel system too lean/too
rich), DTC P0300/P0301/P0302/P0303/P0304/P0305/P0306 (Misfire detected) and DTC P0400 (EGR
flow malfunction)
– DTC P0171/P0172/P0174/P0175 (Fuel system too lean/too rich) and DTC P0400 (EGR flow malfunction)
– DTC P0300/P0301/P0302/P0303/P0304/P0305/P0306 (Misfire detected)
• Be sure to read “PRECAUTIONS FOR ELECTRICAL CIRCUIT SERVICE” in Section 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 respectively.
– MAF sensor, MAP sensor and TP sensor are in good condition and none of power circuits of these sen-
sors is shorted to ground.
2. B+
3. SUZUKI Serial data line
4. K line of ISO 9141
5. Body ground
6. ECM ground
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-11
Engine Diagnostic Flow Table
Refer to following pages for the detail of each step.
Step Action Yes No
1 Customer Complaint Analysis
1) Perform customer complaint analysis.
Was customer complaint analysis performed?Go to Step 2. Perform customer com-
plaint analysis.
2 DTC(s)/Freeze Frame Data Check
1) Check DTC(s)/Freeze frame data.
Is there any malfunction DTC(s)?Record DTC(s)/Freeze
frame data.
Clear DTC(s).
Go to Step 3.Go to Step 4.
3 Visual Inspection
1) Perform visual inspection.
Is there any faulty condition?Repair or replace mal-
function part.
Go to Step 11.Go to Step 5.
4 Visual Inspection
1) Perform visual inspection.
Is there any faulty condition?Repair or replace mal-
function part.
Go to Step 11.Go to Step 8.
5 Trouble Symptom Confirmation
1) Confirm trouble symptom based on cus-
tomer complaint analysis, DTC(s)/freeze
frame data in Step 1.
Is trouble symptom identified?Go to Step 6. Go to Step 7.
6 DTC/Freeze Frame Data Recheck
1) Recheck DTC/freeze frame data.
Is there any malfunction DTC(s)?Go to Step 9. Go to Step 8.
7 DTC/Freeze Frame Data Recheck
1) Recheck DTC/freeze frame data.
Is there any malfunction DTC(s)?Go to Step 9. Go to Step 10.
8 Engine Basic Inspection
1) Check and repair according to “ENGINE
BASIC INSPECTION FLOW TABLE” and
“ENGINE DIAGNOSIS TABLE” in this sec-
tion.
Are check and repair complete?Go to Step 11. Check and repair mal-
function part(s).
Go to Step 11.
9 DTC Trouble Shooting
1) Check and repair according to applicable
“DTC Diag. flow table” in this section.
Are check and repair complete?Go to Step 11. Check and repair mal-
function part(s).
Go to Step 11.
10 Intermittent Problems Check
1) Check for intermittent problems referring to
“Check for Intermittent Problem” in “GEN-
ERAL INFORMATION” section.
Is there any faulty condition?Repair or replace mal-
function part.
Go to Step 11.Go to Step 11.
11 Final Confirmation Test
1) Clear DTC if any.
2) Perform final confirmation test referring to
“DTC CONFIRMATION PROCEDURE” in
this section.
Is there any problem symptom, malfunction
DTC or abnormal condition?Go to Step 6. END.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-13
STEP 2. DIAGNOSTIC TROUBLE CODE (DTC)/FREEZE FRAME DATA CHECK
First, check DTC, referring to “DIAGNOSTIC TROUBLE CODE CHECK” in this section. If DTC is indicated,
record DTC and freeze frame data.
After that clear DTC referring to “DIAGNOSTIC TROUBLE CODE CLEARANCE” in this section. DTC indicates
malfunction that occurred in the system but does not indicate whether it exists now or it occurred in the past and
the normal condition has been restored now. To check which case applies, check the symptom in question
according to Step 5 and recheck DTC according to Step 6, 7.
Attempt to diagnose a trouble based on DTC in this step only or failure to clear the DTC (including pending DTC)
in this step will lead to incorrect diagnosis, trouble diagnosis of a normal circuit or difficulty in troubleshooting.
STEP 3. and 4. VISUAL INSPECTION
Be sure to perform visual check of the following items that support proper function of the engine.
STEP 5. TROUBLE SYMPTOM CONFIRMATION
Based on information obtained in Step 1 “CUSTOMER COMPLAINT ANALYSIS” and Step 2 “DTC/FREEZE
FRAME DATA CHECK”, confirm trouble symptoms. Also, reconfirm DTC according to “DTC CONFIRMATION
PROCEDURE” described in each “DTC FLOW TABLE”.NOTE:
For A/T vehicle, if only DTC P0705, P0715, P0720, P0741, P0743, P0751, P0753, P0756, P0758, or P1875
is indicated in this step, proceed to “DIAGNOSIS” in SECTION 7B1.
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 and/or cooling fan belt - - - - - tension, damage
• Accelerator cable - - - - - play, installation
• A/T 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 - - - - - operation
– Charge warning lamp - - - - - operation
– Engine oil pressure warning lamp - - - - - operation
– Engine coolant temp. meter - - - - - operation
– Fuel lever meter - - - - - operation
– 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 6C
SECTION 6E2
SECTION 6E2
SECTION 6A2
SECTION 8
SECTION 6-1
SECTION 6H
SECTION 8/6A2
SECTION 8
SECTION 8
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.