
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

6-1-10 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) 6-1-13
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

6-1-116 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Table B-1 Fuel Pump Circuit Inspection
WIRING DIAGRAM
INSPECTION
1. To ignition switch 4. Fuel pump relay
2. Main fuse 5. Fuel pump
3. Main relay 6. ECM (PCM)
CAUTION:
Check to make sure that connection is made between correct terminals.
Wrong connection can cause damage to ECM, wire harness etc.
Step Action Yes No
1 Fuel pump operation check :
1) Remove fuel filler cap.
2) Turn ON ignition switch.
Is fuel pump operation sound heard for 3 sec.
after ignition switch ON?Fuel pump circuit is in
good condition.Go to Step 2.
2 Fuel pump circuit check :
1) With ignition switch OFF, remove fuel pump
relay from connector.
2) Check for proper connection to relay at
each terminal.
3) If OK, using service wire, connect terminals
E07-7 and E07-8 of relay connector. (See
Fig.)
Is fuel pump heard to operate at ignition switch
ON?Go to Step 3.“BLU/BLK”, “PNK/BLK” or
“BLK” circuit open or fuel
pump malfunction.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-117
Fig. for Step 2
Table B-2 Fuel Injectors and Circuit Inspection
WIRING DIAGRAM
3 Fuel pump relay check :
1) Check fuel pump relay referring to “FUEL
PUMP RELAY INSPECTION” in Section
6E2.
Is it in good condition?“BLK/WHT” or “WHT/
GRN” circuit open or poor
E61-23 connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace fuel pump relay. Step Action Yes No
1. Fuel pump relay connector
1. To ignition switch 4. Injector No.1 7. Injector No.4 10. ECM (PCM)
2. Main fuse 5. Injector No.2 8. Injector No.5
3. Main relay 6. Injector No.3 9. Injector No.6

6E2-8 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
Electronic Control System
The electronic control system consists of 1) various sensors which detect the state of engine and driving condi-
tions, 2) ECM (PCM) which controls various devices according to the signals from the sensors and 3) various
controlled devices.
Functionally, it is divided into the following sub systems:
•Fuel injection control system
•Heated oxygen sensor heater control system (if equipped)
•Idle air control system
•Fuel pump control system
•Evaporative emission control system
•Ignition control system
•EGR system (if equipped)
Also, with A/T model, PCM controls A/T.
INFORMATION SENSORS CONTROLLED DEVICES OTHERS
1. IAT sensor a : A/C condenser fan motor relay (if equipped) A : Main fuse box
2. MAP sensor (if equipped) b : Ignition coil assemblies B : ECM (PCM)
3. Heated oxygen sensor (sensor 1) (if equipped) c : EVAP canister purge valve C : Data link connector
4. ECT sensor d : EGR valve (if equipped) D : Combination meter
5. TP sensor e : Idle air control valve E : Fuse box
6. MAF sensor f : Injectors F : EVAP canister
7. Camshaft position sensor (CMP sensor) g : Malfunction indicator lamp
8. ABS control module h : Fuel pump relay
9. Crankshaft position sensor (CKP sensor) (if equipped) i : Main relay
10. Power steering pressure switch (PSP switch) j : Oxygen sensor heater relay (if equipped)
11. CO adjusting resistor (if equipped)
12. Monitor connector (if equipped)
13. Transmission range switch (A/T)
14. Knock sensor
NOTE:
Above figure shows left-hand steering vehicle. For right-hand steering vehicle, parts with (*) are
installed at the side of symmetry.

ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-41
INSTALLATION
1) Confirm that vacuum passage on intake manifold is free from
clog.
2) Apply engine oil to O-ring of sensor.
3) Install sensor (1) to intake manifold (2).
4) Connect connector to sensor (1) securely.
Fuel level sensor (sender gauge)
Refer to Section 8C.
Crankshaft position sensor
REMOVAL AND INSTALLATION
Refer to Section 6A4.
INSPECTION
Refer to Section 6-1.
Main relay
INSPECTION
1) Disconnect negative (–) cable at battery.
2) Remove main relay (1) from its connector.
2. Fuel pump relay
3. Fuse box
4. Instrument panel
[A]: Left-hand steering vehicle
[B]: Right-hand steering vehicle

6E2-42 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
3) Check resistance between each two terminals as in table
below.
If check results are as specified, proceed to next operation
check. If not, replace.
Main relay resistance:
4) Check that there is continuity between terminals “A” and “B”
when battery is connected to terminals “C” and “D”.
If malfunction is found, replace.
Fuel pump relay
INSPECTION
1) Disconnect negative (–) cable at battery.
2) Remove fuel pump relay (2) from connector.
3) Structure of fuel pump relay is the same as that of main
relay.
Check its resistance and operation using the same proce-
dure as that for main relay.
If malfunction is found, replace. TERMINALS RESISTANCE
Between “A” and “B”∞
∞∞ ∞ (Infinity)
Between “C” and “D”
79 – 95 Ω
ΩΩ Ω (at 20
°C (68°F))
1. Main relay
3. Fuse box
4. Instrument panel
[A]: Left-hand steering vehicle
[B]: Right-hand steering vehicle