Ecm SUZUKI SX4 2006 1.G Service User Guide

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Outline of troubleshooting
When there is a trouble with CAN, perform “Troubleshooting for Communication Error with Scan Tool Using CAN” and/
or “Troubleshooting for CAN-DTC”. Not using this procedure or performing troubleshooting in any other way may skip
some check points resulting in misdiagnosis or take a longer time than necessary.
1) Checking connector related to CAN
2) Checking CAN line
3) Checking each control module/sensor using “DTC check” or “Bus Check”
4) Checking power and ground connection of each control module/sensor
CAN-DTC
Even when DTC related to CAN (= CAN-DTC) as described below is detected, it is not possible to point out the
specific trouble point by CAN-DTC itself. Be sure to troubleshoot according to “Troubleshooting for CAN-DTC”.
CAN-DTC table
Communication with scan tool
• K line or CAN line is used for communication between each control module and scan tool.
Refer to “CAN schematic and routing diagram: ” to determine which line is used for communication between each
control module and scan tool.
• ECM and TCM use CAN line for communication with scan tool. Even if CAN has a trouble other than between DLC
and BCM, communication may also fail between scan tool and these control modules. In such case, perform
troubleshooting according to “Troubleshooting for Communication Error with Scan Tool Using CAN”.
• BCM, ABS control module and 4WD control module use K-line for communication with scan tool. Even if CAN has a
trouble, it is possible to communicate between scan tool and these control modules.
Bus check with SUZUKI scan tool
SUZUKI scan tool (SUZUKI-SDT) efficiently diagnoses a CAN bus malfunction by “Communication Bus Check” and
“Communication Malfunction DTC” under “Bus check”.
“Communication Bus Check” can display all control modules/sensors name communicated by CAN.
Also, “Communication Malfunction DTC” can display only CAN-DTC which is detected by the control modules (ECM
and TCM) communicating with scan tool using CAN line.
[A]: Non-Taiwan model [C]: CAN high line (RED) [E]: K-line
[B]: Taiwan model [D]: CAN low line (WHT)
No. Part Name Communication with scan tool Monitor of CAN-DTC
1. ABS control module K-line Not available
2. ECM CAN Available
3. TCM CAN Available
4. BCM K-line Available
5. Keyless start control module Not available Available
6. 4WD control module K-line Available
7. Combination meter Not available Not available
8. CAN junction connector — —
9. DLC — —
Detected Control Module CAN-DTC
ECM U0073/U0101/U0121/U0140/P1618
TCM U0073/U0100
BCM U0073/U0100/U0101/U0155/U1144
4WD control module U0073/U0100/U0121/U0155
Keyless start control module No.31/No.33

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General Description
Statement on Cleanliness and CareS6RW0D1101001
An automobile engine is a combination of many
machined, honed, polished and lapped surfaces with
tolerances that are measured in the thousands of an
millimeter (ten thousands of an inch).
Accordingly, when any internal engine parts are
serviced, care and cleanliness are important.
It should be understood that proper cleaning and
protection of machined surfaces and friction areas is part
of the repair procedure. This is considered standard
shop practice even if not specifically stated.
• A liberal coating of engine oil should be applied to
friction areas during assembly to protect and lubricate
the surfaces on initial operation.
• Whenever valve train components, pistons, piston
rings, connecting rods, rod bearings, and crankshaft
journal bearings are removed for service, they should
be retained in order.
At the time of installation, they should be installed in
the same locations and with the same mating
surfaces as when removed.
• Battery cables should be disconnected before any
major work is performed on the engine.
Failure to disconnect cables may result in damage to
wire harness or other electrical parts.
• The four cylinders of the engine are identified by
numbers; No.1 (1), No.2 (2), No.3 (3) and No.4 (4)
counted from crankshaft pulley side to flywheel side.
Engine Diagnosis General DescriptionS6RW0D1101002
NOTE
There are two types of OBD system
depending on the vehicle specification.
For identification, refer to “Precaution on On-
Board Diagnostic (OBD) System”.

This vehicle is equipped with an engine and emission
control system which are under control of ECM.
The engine and emission control system in this vehicle
are controlled by ECM. ECM has an On-Board
Diagnostic system which detects a malfunction in this
system and abnormality of those parts that influence the
engine exhaust emission. When diagnosing engine
troubles, be sure to have full understanding of the outline
of “On-Board Diagnostic System Description” and each
item in “Precautions in Diagnosing Trouble” and execute
diagnosis according to “Engine and Emission Control
System Check”.
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 and Emission Control System
Check”.
On-Board Diagnostic System DescriptionS6RW0D1101003
NOTE
There are two types of OBD system
depending on the vehicle specification.
For identification, refer to “Precaution on On-
Board Diagnostic (OBD) System”.

Euro OBD model
ECM in this vehicle has the 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 circuit 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.)
1
234
I3RM0A110001-01

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• As a condition for detecting a malfunction in some
areas in the system being monitored by ECM 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
conditions then are stored in ECM memory as freeze
frame data. (For the details, refer to description on
“Freeze Frame Data: ”.)
• It is possible to communicate via DLC (3) by using not
only SUZUKI scan tool (2) but also CAN
communication OBD generic scan tool. (Diagnostic
information can be accessed by using a scan tool.)
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 and engine
shutoff.2 Driving Cycle Detection Logic
The malfunction detected in the first driving cycle is
stored in ECM memory (in the form of pending DTC) but
the malfunction 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 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
has a function to store each freeze frame data for three
different malfunctions in the order as each 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.
For example
1
2 3
I5RW0C110001-01
I5RW0C110028-03

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Priority of freeze frame data:
ECM has 4 frames where the freeze frame data can be stored. The first frame stores the freeze frame data of the
malfunction which was detected first. However, the freeze frame data stored in this frame is updated according to the
priority described. (If malfunction as described in the upper square “1” is detected while the freeze frame data in the
lower square “2” has been stored, the freeze frame data “2” will be updated by the freeze frame data “1”.)
In the 2nd through the 4th frames, the freeze frame data of each malfunction is stored in the order as each malfunction
is detected. These data are not updated.
Shown in the table are examples of how freeze frame data are stored when two or more malfunctions are detected.
Freeze frame data clearance:
The freeze frame data is cleared at the same time as clearance of DTC.
Non-Euro-OBD Model
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 malfunction indicator lamp (MIL) (1).
• Heated oxygen sensor-1
• Heated oxygen sensor-2
• ECT sensor
•TP sensor
• Throttle actuator
• MAF sensor
• IAT sensor
• CMP sensor
• CKP sensor
• Knock sensor
• Wheel speed sensor
• CPU (Central Processing Unit) of ECM
• APP sensor
• Oil control valve (VVT model)
• Barometric pressure sensor
• A/C refrigerant pressure sensor
• ECM backup power supply
• Fuel level sensor
•CANECM and MIL operate as follows.
• MIL lights 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 MIL in
the combination meter 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), MIL turns OFF.
• When ECM detects a trouble which has occurred in
the above areas, it makes MIL turn ON while the
engine is running to warn the driver of such
occurrence 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 or it is cleared by SUZUKI scan tool
(SUZUKI-SDT) (2).)
For further detail of the checking / clearing procedure,
refer to “DTC Check” or “DTC Clearance”. Priority Freeze frame data in frame 1
1Freeze frame data at initial detection of malfunction among misfire detected (P0300 – P0304), fuel
system too lean (P0171) and fuel system too rich (P0172)
2 Freeze frame data when a malfunction other than those in “1” is detected
Malfunction detected orderFrame
Frame 1 Frame 2 Frame 3 Frame 4
Freeze frame data to
be updated1st freeze frame
data2nd freeze frame
data3rd freeze frame
data
No malfunction No freeze frame data
1P0401 (EGR)
detectedData at P0401
detectionData at P0401
detection——
2P0171 (Fuel system)
detectedData at P0171
detectionData at P0401
detectionData at P0171
detection—
3P0300 (Misfire)
detectedData at P0171
detectionData at P0401
detectionData at P0171
detectionData at P0300
detection
4P0301 (Misfire)
detectedData at P0171
detectionData at P0401
detectionData at P0171
detectionData at P0300
detection

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For information about the following items, refer to “Euro
OBD model: ”.
• Warm-up cycle
• Driving cycle
• 2 driving cycle detection logic
• Pending DTC
Data Link Connector (DLC)S6RW0D1101011
NOTE
There are two types of OBD system
depending on the vehicle specification.
For identification, refer to “Precaution on On-
Board Diagnostic (OBD) System”.

DLC (1) is in compliance with SAE J1962 in the shape of
connector and pin assignment.
OBD CAN Hi line (6) and Low line (3) (CAN line of ISO
15765-4) are used for SUZUKI scan tool (SUZUKI-SDT)
(7) or CAN communication OBD generic scan tool to
communicate with ECM (included in immobilizer control)
and TCM (Transmission Control Module) (for A/T
model).
Engine and Emission Control System
Description
S6RW0D1101004
The engine and emission control system is divided into 4
major sub-systems: air intake system, fuel delivery
system, electronic control system and emission control
system.
Air intake system includes air cleaner, throttle body and
intake manifold.
Fuel delivery system includes fuel pump, delivery pipe,
etc.
Electronic control system includes ECM, various sensors
and controlled devices.
Emission control system includes EGR, EVAP and PCV
system.
3. DLC
1
2 3
I5RW0C110001-01
2. B + (Unswitched vehicle battery positive)
4. ECM ground (Signal ground)
5. Vehicle body ground (Chassis ground)
2
45 6
1
9 10 11 12 13 14 15 16
1 2 3 4 5 6 7 8
7
3
1I7RW01110092-01

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CAN Communication System DescriptionS6RW0D1101005
ECM (1), ABS control module (2), BCM (3), combination meter (4), keyless start control module (if equipped with
keyless start control system) (5), 4WD control module (for 4WD model) (6)and TCM (for A/T model) (7) of this vehicle
communicate control data between each control module.
Communication of each control module is established by CAN (Controller Area Network) communication system.
CAN communication system uses the serial communication in which data is transmitted at a high speed. It uses a
twisted pair of two communication lines for the high-speed data transmission. As one of its characteristics, multiple
control modules can communicate simultaneously. In addition, it has a function to detect a communication error
automatically. Each module reads necessary data from the received data and transmits data. ECM communicates
control data with each control module as follows.
[A]
[B]
6
4
51 7
2
3
6
4
51 7
2
3
I6RW0D110002-01
[A]: Non-Taiwan model [B]: Taiwan model

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ECM Transmission Data
ECM Reception Data
BCM TCMCombination
Meter
DATA ECM Transmit
Brake pedal switch signal
Vehicle speed signal
Engine speed signal
Engine torque signal
Accelerator pedal position signal
4WD Control
ModuleKeyless Start
Control
Module
A/C refrigerant pressure
signal
A/C compressor clutch signal
Engine type signal
Immobilizer indicator light control
signal
MIL control signal
Engine coolant temperature signal
Fuel level signal
Fuel consumption signal
Throttle position signal
Driving cycle active
Warm up cycle active
Odometer signal
I6RW0D110003-02
DATA ECM Receive
ABS control
module
Transmission oil temperature signal
Transmission warning light signal Vehicle speed pulse signal A/T selector lever position signal
Transmission actual gear position signal
Wheel speed signal (front right)
Wheel speed signal (front left)
ABS indication signal
A/C switch ON signal
Electric load signalBCM
4WD mode status
Torque request signalTCM
MIL control signal4WD control
module
I6RW0D110013-02

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Air Intake System DescriptionS6RW0D1101006
The main components of the air intake system are air cleaner (1), air cleaner outlet hose (2), electric throttle body (3)
(for the details, refer to “Description of Electric Throttle Body System”.), and intake manifold (4).
The air (by the amount corresponding to throttle valve (5) opening and engine speed) is filtered by the air cleaner,
distributed by the intake, and finally drawn into each combustion chamber. Electric throttle body is not equipped with
IAC valve for idle speed control. Idle speed control is done by the throttle actuator (6) which opens/closes the throttle
valve. (For the details, refer to “Description of Electric Throttle Body System”.)
Description of Electric Throttle Body System CalibrationS6RW0D1101007
ECM calculates controlled opening of the throttle valve on the basis of the completely closed throttle valve position of
the electric throttle body system. The completely closed position data is saved in memory of ECM. However, the
completely closed position of the throttle valve of the electric throttle body system (signal voltage from throttle position
sensor when throttle is completely closed) differs one from the other depending on individual differences of the throttle
valve and throttle position sensor. As such individual differences must be taken into account for controlling the throttle
valve, it is necessary to register the completely closed throttle valve position data in ECM. When such data is
registered in ECM, it is saved in RAM (memory) of ECM and used as the base data for controlling the throttle valve.
This data is cleared, when any of the works described in “Precautions of Electric Throttle Body System Calibration” is
performed.
Also, after replacement of the throttle body and/or APP sensor assembly, the completely closed position data in
memory of ECM must be cleared once and a new one must be registered, or ECM cannot judge the complete closure
position properly.
For the procedure to register such data, refer to “Electric Throttle Body System Calibration in Section 1C”. (After the
completely closed position data is cleared, ECM, for the first time only, opens and closes the throttle valve for about 5
seconds after the ignition switch is turned ON position, for registration of the completely closed throttle valve position.
If the engine is started during this registration process, such symptom as “longer cranking time” or “slow rise of
revolution speed immediately after start-up” may occur. However, turning OFF the ignition switch once and restarting
will set correct registration.)
Description of Electric Throttle Body SystemS6RW0D1101009
The Electric Throttle Body System consists of electric throttle body assembly, accelerator pedal position (APP) sensor
assembly, ECM and throttle actuator control relay.
Among them, assembly components are as follows.
• Electric throttle body assembly: throttle valve, throttle actuator, 2 throttle position sensors
• APP sensor assembly: Accelerator pedal, 2 accelerator position sensors
42
1
3
5
6
I5RW0A110006-02

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Operation Description
ECM (5) detects opening (depressed extent of pedal) of the accelerator pedal based on signal voltage of the APP
sensor (1) and using that data and engine operation condition, it calculates the optimum throttle valve opening. On the
other hand, it detects the throttle valve opening based on the signal voltage of the throttle position sensor (3) included
in the throttle body (2) and compares it with the above calculated optimum throttle valve opening. When there is a
difference between them, ECM controls the duty ratio (100% – 0%) according to this difference to drive the throttle
actuator (motor) (4) included in the throttle body. When there is no difference, ECM controls the duty ratio to about
15% to maintain the throttle valve opening. In this way, the throttle valve (17) is opened and closed to achieve the
optimum throttle valve opening.
In this system, as the throttle position sensor and APP sensor have 2 sensors (main and sub) each, highly accurate
and highly reliable control and abnormality detection are assured. Also, when ECM detects an abnormality in the
system, it turns off the throttle actuator control relay (8) to stop controlling the throttle actuator. When the throttle
actuator control relay is turned off, the throttle valve is fixed at the opening of about 7° from its completely closed
position (default opening) by the force of the return spring and open spring included in the throttle body.
This throttle body is not equipped with IAC valve for idle speed control. Idle speed control is done by the throttle
actuator which opens/closes the throttle valve.
Electronic Control System Description
The electronic control system consists of 1) various
sensors which detect the state of engine and driving
conditions, 2) ECM 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
• Ignition control system
• Electric throttle body control system
• Fuel pump control system
• Radiator cooling fan control system
• Evaporative emission control system
• EGR system (if equipped)
• Oxygen sensor heater control system• A/C control system (if equipped with A/C)
• Camshaft position control system
• Immobilizer control system
• Controller (computer) communication system
Especially, ECM (Engine Control Module), BCM (Body
electrical Control Module), combination meter, ABS /
control module, keyless start control module (if equipped
with keyless start control system), TCM (Transmission
Control Module) (for A/T model) and 4WD control
module (if equipped) intercommunicate by means of
CAN (Controller Area Network) communication.
4 12
1735
6
7 8
9
10
11
12
13
14
1516
18
I4RS0B110007-02
6. CPU 11. APP sensor (main) signal 15. Drive signal of throttle actuator
7. Drive circuit of throttle actuator 12. APP sensor (sub) signal 16. Power supply of throttle actuator
9. From “THR MOT” fuse 13. Throttle position sensor (main) signal 18. Control signal of throttle actuator control relay
10. From main relay 14. Throttle position sensor (sub) signal

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Engine and Emission Control System Flow Diagram
Intake manifoldExhaust
manifold
Exhaust gas Air
Fuel Vapor
War m up
catalystExhaust
pipe
EVAP canister
purge valve
Fuel injector
ECT
sensor
ECM
Heater
control
Heater
control
(if equipped)
Barometric pressure sensor HO2S-1HO2S-2
(if equipped) Engine
CMP
sensorCKP
sensor
Knock
sensorIgnition
coil with
igniter
APP sensor
A/C compressor
clutch
Generator
Immobilizer
coil antenna
P/S control
module
Brake light
switch
Air cleaner
IAT
sensorMAF
sensor
A/C refrigerant
pressure sensor
TP
sensor Throttle body
assembly
Throttle
actuator
A/C condenser
fan
DLC
Radiator
fan
Combination meter
· MIL
· Coolant Temp.
· Immobilizer indicator light
· Tachometer
· Speedometer
· Fuel level
· Odometer4WD
control module
Wheel speed
sensor (VSS)
(M/T)
· Electric load
· A/C switch ON
BCM
Keyless start
control module
ABS control module
Blower speed
selector
MAP sensor
(if equipped)EGR valve
(if equipped)
Check
valve
EVAP
canister
Fuel level sensorFuel tankFuel
pump
CMP actuator
oil control valve
(VVT model)
TCM
Output shaft speed
(VSS) sensor (A/T)
Three way
catalyst (if
equipped)
I6RW0D110004-03