Inspection of ecm and its circuits SUZUKI SWIFT 2008 2.G Service Manual Online

Downloaded from www.Manualslib.com manuals search engine Aux. Emission Control Devices: 1B-2
EVAP Canister Purge Valve and Its Circuit
Inspection
S7RS0B1206002
WARNING!
Do not apply vacuum by mouth; otherwise
harmful fuel vapor can be breathed in.

CAUTION!
Do not apply vacuum more than –86 kPa (–
12.47 psi); otherwise EVAP canister purge
valve could be damaged.

1) Prepare to operate EVAP canister purge valve as follows.
a) When using SUZUKI scan tool:
i) Connect SUZUKI scan tool to DLC (1) with ignition switch turned OFF and disconnect
purge valve vacuum hoses from intake
manifold and EVAP canister.
ii) Turn ON ignition switch, clear DTC and select “MISC TEST” mode on SUZUKI scan
tool.
Special tool
(A): SUZUKI scan tool b) When not using SUZUKI scan tool:
NOTE
Before performed this check, be sure to read
the “Precautions of ECM Circuit Inspection in
Section 1A”.

i) Disconnect purge valve vacuum hoses from
intake manifold and EVAP canister.
ii) Remove ECM from it s bracket referring to
“ECM Removal and Inst allation in Section
1C”.
iii) Connect special tool between ECM and ECM connector referring to “Inspection of ECM
and Its Circuits in Section 1A”
iv) Turn ON ignition switch. Using service wire, ground “C37-29” terminal
circuit of special tool (valve ON: “B”) and
unground it (valve OFF: “A”).
2) Check purge valve for operation and vacuum passage for clog when valve is switched ON and
OFF by using SUZUKI scan tool or service wire.
If check result is not satisfactory, check vacuum
hoses, EVAP canister purge valve, wire harness and
connections.
EVAP canister purge valve specification
[A] Valve OFF: When vacuum (–60 kPa (–8.7 psi))
is applied to hose (1), vacuum can be applied.
[B] Valve ON: When vacuum is applied to hose
(1), vacuum can not be applied.
Special tool
(A): 09917–47011
(A)
1
I4RS0B120003-03
“C37-29”“A”
“B”
I4RS0B120006-02
[A] [B]
1
(A)1
(A)
I3RB0A120005-02

Downloaded from www.Manualslib.com manuals search engine Engine Electrical Devices: 1C-11
MAF and IAT Sensor On-Vehicle InspectionS7RS0B1306018
NOTE
Before performed this inspection, be sure to
read the “Precautions of ECM Circuit
Inspection in Section 1A”.

1) Disconnect negative (–) cable at battery.
2) Disconnect MAF and IAT sensor connector.
3) Connect voltmeter to “BLK/RED” wire terminal (2) of
MAF and IAT sensor connector (1) disconnected and
ground.
4) Turn ON ignition switch position and check that voltage is battery voltage.
If not, check if wire harness is open or connection is
poor.
5) Turn OFF ignition switch position and connect connector to MAF and IAT sensor.
6) Remove ECM from its bracket referring to “ECM Removal and Installation”.
7) Connect special tool between ECM and ECM connector referring to “Inspection of ECM and Its
Circuits in Section 1A”.
8) Turn ON ignition switch position and check MAF signal voltage between “C37-26” terminal circuit and
“C37-27” terminal circuit of special tool.
MAF signal voltage between “C37-26” terminal
circuit and “C37-27” termi nal circuit of special
tool
MAF signal voltage of MAF and IAT sensor with
ignition switch turned ON: 0.5 – 1.0 V
9) Start engine and check that voltage is lower than 5 V and it rises as engine speed increases.
MAF signal voltage between “C37-26” terminal
circuit and “C37-27” termi nal circuit of special
tool
MAF signal reference voltage of MAF and IAT
sensor at specified Idle speed: 1.3 – 1.8 V 10) If check result is not as
specified above, cause may
lie in wire harness, connec tor connection, MAF and
IAT sensor or ECM.
MAF and IAT Sensor Removal and InstallationS7RS0B1306019
CAUTION!
• Do not disassemble MAF and IAT sensor.
• Do not expose MAF and IAT sensor to any shock.
• Do not clean MAF and IAT sensor.
• If MAF and IAT sensor has been dropped, it should be replaced.
• Do not blow compressed air by using air gun or the like.
• Do not put finger or any other object into MAF and IAT sensor. Malfunction may
occur.

Removal
1) Disconnect negative (–) cable at battery.
2) Disconnect MAF and IAT sensor connector.
3) Remove air cleaner case (1).
4) Remove MAF and IAT sensor (2) from air cleaner case.
Installation
Reverse removal procedure noting the followings.
• Tighten MAF and IAT sensor screws to specified torque.
Tightening torque
MAF and IAT sensor screw (a): 1.5 N·m (0.15 kgf-
m, 1.1 lb-ft)
• Connect MAF and IAT sensor connector securely.
1. ECM
I3RB0A130009-01
“C37-27” “C37-26” 1
I4RS0A130009-01
1
2
I4RS0A130010-01
(a)
I4RS0A130011-01

Downloaded from www.Manualslib.com manuals search engine Engine Electrical Devices: 1C-13
Without Using SUZUKI Scan Tool1) Measure sensor voltage between “C37-23” terminal of ECM connector and vehicle body ground referring
to “Inspection of ECM and Its Circuits in Section 1A”.
If check result is satisfactory, electric load current
sensor is in good condition.
If check result is not satisfactory, check the following
parts and circuit.
• Electric load current sensor circuit (power, ground and output)
• Following charging system components – Battery (refer to “Battery Inspection in Section
1J”)
– Generator (refer to “Generator Inspection in Section 1J”)
– Generator output control circuit (refer to “Generator Test (Undercharged Battery Check)
in Section 1J”)
– Generator field coil monitor circuit (refer to “Generator Inspection in Section 1J”) If electric load current sensor circuit and charging
system is in good condition,
electric load current sensor
(1) is faulty.
Specifications
Tightening Torque SpecificationsS7RS0B1307001
Reference:
For the tightening torque of fastener not specified in this section, refer to “Fasteners Information in Section 0A”.
2. Main fuse box
2
1
I5RS0C130001-01
Fastening part
Tightening torque
Note
N ⋅mkgf-mlb-ft
ECM mounting bolt 8 0.8 6.0 )
APP sensor assembly nut 5.5 0.55 4.0 )
ECT sensor 15 1.5 11.0 )
Heated oxygen sensor 45 4.5 32.5 )
CMP sensor bolt 10 1.0 7.5 )
CKP sensor bolt 10 1.0 7.5 )
Knock sensor 22 2.2 16.0 )
MAF and IAT sensor screw 1.5 0.15 1.1 )

Downloaded from www.Manualslib.com manuals search engine 1H-4 Ignition System:
Diagnostic Information and Procedures
Ignition System Symptom DiagnosisS7RS0B1804001
Reference Waveform of Ignition SystemS7RS0B1804002
Refer to “Reference waveform No.5”, “Reference waveform No.6” and “Reference waveform No.7” under “Inspection
of ECM and Its Circuits in Section 1A” for waveform of Ignition trigger signal.
Ignition System CheckS7RS0B1804003
Condition Possible cause Correction / Reference Item
Engine cranks, but will
not start or hard to start
(No spark) Blown fuse for ignition coil
Replace.
Loose connection or disconnection of
lead wire or high-tension cord(s) Connect securely.
Faulty high-tension cord(s) Replace.
Faulty spark plug(s) Replace.
Faulty ignition coil Replace ignition coil assembly.
Faulty CKP sensor or CKP sensor plate Clean, tighten or replace.
Faulty CMP sensor or sensor rotor tooth
of camshaft Clean, tighten or replace.
Faulty ECM Replace.
Poor fuel economy or
engine performance Incorrect ignition timing
Check related sensors and CKP sensor plate.
Faulty spark plug(s) or high-tension
cord(s) Adjust, clean or replace.
Faulty ignition coil assembly Replace.
Faulty CKP sensor or CKP sensor plate Clean, tighten or replace.
Faulty CMP sensor or sensor rotor tooth
of camshaft Clean, tighten or replace.
Faulty knock sensor Replace.
Faulty ECM Replace.
StepAction YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check in
Section 1A”.
2 Ignition spark test
1) Check all spark plugs for condition and type referring to
“Spark Plug Inspection”.
2) If OK, perform ignition spark test referring to “Ignition Spar k Tes t”.
Is spark emitted from all spark plugs? Go to Step 13. Go to Step 3.
3 DTC check
1) Perform DTC check referring to “DTC Check in Section
1A”.
Is DTC stored in ECM? Go to applicable DTC
diag. flow.
Go to Step 4.
4 Electrical connection check
1) Check ignition coil assemblies and high-tension cords
for electrical connection.
Are they connected securely? Go to Step 5.
Connect securely.
5 High-tension cords check
1) Check high-tension cord for resistance referring to
“High-Tension Cord Inspection”.
Is check result satisfactory? Go to Step 6.
Replace high-tension
cord(s).

Downloaded from www.Manualslib.com manuals search engine Ignition System: 1H-5
6Ignition coil assembly power supply and ground circuit
check
1) Check ignition coil assembly power supply and ground
circuits for open and short.
Are circuits in good condition? Go to Step 7.
Repair or replace.
7 Ignition coil assembly check
1) Check ignition coil for resistance referring to “Ignition
Coil Assembly (Including ignitor) Inspection”.
Is check result satisfactory? Go to Step 8.
Replace ignition coil
assembly.
8 CKP sensor check
1) Check CKP sensor referring to “CKP Sensor Inspection
in Section 1C”.
Is check result satisfactory? Go to Step 9.
Tighten CKP sensor
bolt, replace CKP
sensor or CKP sensor
plate.
9 CMP sensor check
1) Check CMP sensor referring to “Camshaft Position
(CMP) Sensor Inspection in Section 1C”.
Is check result satisfactory? Go to Step 10. Tighten CMP sensor
bolt, replace CMP
sensor or intake
camshaft.
10 Ignition trigger signal circuit check
1) Check ignition trigger signal wire for open, short and
poor connection.
Is circuit in good condition? Go to Step 11. Repair or replace.
11 A known-good ignition coil assembly substitution
1) Substitute a known-good ignition coil assembly and then
repeat Step 2.
Is check result of Step 2 satisfactory? Go to Step 12. Substitute a known-
good ECM and then
repeat Step 2.
12 Knock sensor check
1) Confirm that knock sensor circuit is in good condition
referring to “DTC P0327 / P0328: Knock Sensor 1 Circuit
Low / High in Section 1A”.
2) Check oscilloscope waveform of knock sensor signal
referring to “Reference waveform No.25” and
“Reference waveform No.26” under “Inspection of ECM
and Its Circuits in Section 1A”.
Is check result satisfactory? Go to Step 13. Substitute a known-
good knock sensor and
recheck.
13 Ignition timing check
1) Check initial ignition timing and ignition timing advance
referring to “Ignition Timing Inspection”.
Is check result satisfactory? System is in good
condition.
Check CMP sensor,
CMP sensor rotor tooth
of camshaft, CKP
sensor, CKP sensor
plate and/or input
signals related to this
system.
Step
Action YesNo

Downloaded from www.Manualslib.com manuals search engine Starting System: 1I-2
ConditionPossible cause Correction / Reference Item
Motor not running (No
operating sound of
magnetic switch) Shift lever switch is not in P or N, or not
adjusted (A/T)
Shift in P or N, or
adjust switch. (A/T)
Battery run down Recharge battery.
Battery voltage too low due to battery
deterioration Replace battery.
Poor contact in battery terminal
connection Retighten or replace.
Loose grounding cable connection Retighten.
Fuse set loose or blown off Tighten or replace.
Poor contacting action of ignition switch
and magnetic switch Replace.
Lead wire coupler loose in place Retighten.
Open-circuit between ignition switch and
magnetic switch Repair.
Open-circuit in pull-in coil Replace magnetic switch.
Brushes are seating poorly or worn
down Repair or replace.
Poor sliding of plunger and/or pinion Repair.
Faulty starting motor control relay “Main Relay, Fuel Pump Relay and Starting
Motor Control Relay Inspection in Section 1C”.
Faulty ECM and its circuit “Inspection of ECM and Its Circuits in Section
1A”.
Motor not running
(Operating sound of
magnetic switch heard) Battery run down
Recharge battery.
Battery voltage too low due to battery
deterioration Replace battery.
Loose battery cable connections Retighten.
Burnt main contact point, or poor
contacting action of magnetic switch Replace magnetic switch.
Brushes are seating poorly or worn
down Repair or replace.
Weakened brush spring Replace.
Burnt commutator Replace armature.
Layer short-circuit of armature Replace.
Crankshaft rotation obstructed Repair.
Starting motor running
but too slow (small
torque) (If battery and
wiring are satisfactory,
inspect starting motor) Insufficient contact
of magnetic switch
main contacts Replace magnetic switch.
Layer short-circuit of armature Replace.
Disconnected, burnt or worn
commutator Repair commutator or replace armature.
Worn brushes Replace brush.
Weakened brush springs Replace spring.
Burnt or abnormally worn end bush Replace bush.
Starting motor running,
but not cranking engine Worn pinion tip
Replace over-running clutch.
Poor sliding of over-running clutch Repair.
Over-running clutch slipping Replace over-running clutch.
Worn teeth of ring gear Replace flywheel (M/T) or drive plate (A/T).
Noise Abnormally worn bush Replace bush.
Worn pinion or worn teeth of ring gear Replace over-running clutch, flywheel (M/T) or
drive plate (A/T).
Poor sliding of pinion (failure in return
movement) Repair or replace.
Worn internal or planetary gear teeth Replace.
Lack of oil in each part Lubricate.
Starting motor does not
stop running Fused contact points of magnetic switch
Replace magnetic switch.
Short-circuit between turns of magnetic
switch coil (layer short-circuit) Replace magnetic switch.
Failure of returning action in ignition
switch Replace.

Downloaded from www.Manualslib.com manuals search engine 4F-50 Electronic Stability Program:
DTC Troubleshooting
DTC U1100: Lost Communication with ECM (Reception Error)S7RS0B4604058
Wiring Diagram
Refer to “Wiring Diagram” under “DTC U1073: Control Module Communication Bus Off”.
DTC Detecting Condition and Trouble Area
DTC TroubleshootingStep Action Yes No
1 Was “Electronic Stability Pr ogram Check” performed? Go to Step 2. Go to “Electronic
Stability Program
System Check”.
2 DTC check for ESP®
1) Check connection of connectors of all control modules
communicating by means of CAN.
2) Recheck DTC for ESP ®.
Is DTC U1073 indicated? Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
3 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of all control modules
communicating by means of CAN.
3) Check CAN communication circuit between control modules for open, short and high resistance.
Is each CAN communication circuit in good condition? Go to Step 4. Repair or replace the
CAN communication
line.
4 DTC check for ESP®
1) Connect connectors of disconnected control modules
communicating by means of CAN.
2) Disconnect each connector. •ECM
• Keyless start control module (if equipped)
• Combination meter
• Steering angle sensor
•BCM
3) Recheck DTC for ESP ®.
Is DTC U1073 detected? Check ESP
® control
module power and
ground circuit. If circuits
are OK, substitute a
known-good ESP ®
hydraulic unit / control
module assembly and
recheck. Check applicable
control module power
and ground circuit. If
circuit is OK, substitute
a known-good
applicable control
module and recheck.
DTC Detecting Condition
Trouble Area
ECM message data is missing from CAN communication. • CAN communication circuit
•ECM
• ESP® control module
Step Action YesNo
1 Was “Electronic Stability Pr ogram Check” performed? Go to Step 2.Go to “Electronic
Stability Program
System Check”.
2 DTC check for ESP®
1) Check DTC for ESP ®.
Is DTC U1100 and DTC U1073 detected together? Go to “DTC U1073:
Control Module
Communication Bus
Off”.Go to Step 3.
3 DTC check for ECM
1) Check DTC for ECM.
Is DTC P1674 detected? Go to “DTC P1674:
CAN Communication
(Bus Off Error) in
Section 1A”.Go to Step 4.

Downloaded from www.Manualslib.com manuals search engine Electronic Stability Program: 4F-51
DTC U1126: Lost Communication with Steering Angle Sensor (Reception Error)S7RS0B4604043
Wiring Diagram
Refer to “Wiring Diagram” under “DTC U1073: Control Module Communication Bus Off”.
DTC Detecting Condition and Trouble Area
DTC Troubleshooting4
Check each control module connectors
1) Check connection of connectors of all control modules
communicating by means of CAN.
2) Check DTC for ESP ®.
Is DTC U1100 detected? Go to Step 5. Check for intermittent
trouble referring to
“Intermittent and Poor
Connection Inspection
in Section 00”.
5 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of ESP ® control module and
ECM communicating by means of CAN.
3) Check CAN communication circuit between ESP®
control module and ECM for open, short and high
resistance.
Is each CAN communication circuit in good condition? Repair or replace the
CAN communication
line.
Go to Step 6.
6 CAN communication circuit check
1) Disconnect connectors of all control modules
communicating by means of CAN.
2) Check CAN communication circuit between control modules other than Step 5 for open, short and high
resistance.
Is each CAN communication circuit in good condition? Go to Step 7. Repair or replace the
CAN communication
line.
7 DTC check for ESP®
1) Connect connectors of disconnected control modules
communicating by means of CAN.
2) Disconnect each connector. •ECM
• Keyless start control module (if equipped)
• Combination meter
• Steering angle sensor
•BCM
3) Recheck DTC for ESP ®.
Is DTC U1100 detected? Check ESP
® control
module power and
ground circuit. If circuits
are OK, substitute a
known-good ESP ®
hydraulic unit / control
module assembly and
recheck. Check applicable
control module power
and ground circuit. If
circuit is OK, substitute
a known-good
applicable control
module and recheck.
Step Action Yes No
DTC Detecting Condition
Trouble Area
Steering angle sensor message data is missing from CAN
communication. • CAN communication circuit
• Steering angle sensor
• ESP
® control module
Step Action YesNo
1 Was “Electronic Stability Pr ogram Check” performed? Go to Step 2.Go to “Electronic
Stability Program
System Check”.
2 DTC check for ESP®
1) Check DTC for ESP ®.
Is DTC U1126 and DTC U1073 detected together? Go to “DTC U1073:
Control Module
Communication Bus
Off”.Go to Step 3.

Downloaded from www.Manualslib.com manuals search engine 4F-52 Electronic Stability Program:
DTC U1140: Lost Communication with BCM (Reception Error)S7RS0B4604045
Wiring Diagram
Refer to “Wiring Diagram” under “DTC U1073: Control Module Communication Bus Off”.
DTC Detecting Condition and Trouble Area3
Check each control module connectors
1) Check connection of connectors of all control modules
communicating by means of CAN.
2) Check DTC for ESP ®.
Is DTC U1126 detected? Go to Step 4. Check for intermittent
trouble referring to
“Intermittent and Poor
Connection Inspection
in Section 00”.
4 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of ESP ® control module, BCM
and steering angle sensor communicating by means of
CAN.
3) Check CAN communication circuit for open, short and high resistance.
• Between ESP ® control module and BCM
• Between steering angle sensor and BCM
Is each CAN communication circuit in good condition? Repair or replace the
CAN communication
line.
Go to Step 5.
5 CAN communication circuit check
1) Disconnect connectors of all control modules
communicating by means of CAN.
2) Check CAN communication circuit between control modules other than Step 4 for open, short and high
resistance.
Is each CAN communication circuit in good condition? Go to Step 6. Repair or replace the
CAN communication
line.
6 DTC check for ESP®
1) Connect connectors of disconnected control modules
communicating by means of CAN.
2) Disconnect each connector. •ECM
• Keyless start control module
• Combination meter
• Steering angle sensor
•BCM
3) Check DTC for ESP ®.
Is DTC U1126 detected? Check ESP
® control
module power and
ground circuit. If circuits
are OK, substitute a
known-good ESP ®
hydraulic unit / control
module assembly and
recheck. Check applicable
control module power
and ground circuit. If
circuit is OK, substitute
a known-good
applicable control
module and recheck.
Step Action Yes No
DTC Detecting Condition
Trouble Area
BCM message data is missing from CAN communication. • CAN communication circuit
•BCM
• ESP® control module

Downloaded from www.Manualslib.com manuals search engine Electronic Stability Program: 4F-53
DTC TroubleshootingStep Action Yes No 1 Was “Electronic Stability Pr ogram Check” performed? Go to Step 2. Go to “Electronic
Stability Program
System Check”.
2 DTC check for ESP®
1) Check DTC for ESP ®.
Is DTC U1140 and DTC U1073 detected together? Go to “DTC U1073:
Control Module
Communication Bus
Off”.Go to Step 3.
3 DTC check for BCM
1) Check DTC for BCM.
Is DTC U1073 detected? Go to “DTC U1073 (No.
1073): Control Module
Communication Bus Off
in Section 10B”.Go to Step 4.
4 Check each control module connectors
1) Check connection of connectors of all control modules
communicating by means of CAN.
2) Check DTC for ESP ®.
Is DTC U1140 detected? Go to Step 4. Check for intermittent
trouble referring to
“Intermittent and Poor
Connection Inspection
in Section 00”.
5 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of ESP ® control module and
BCM communicating by means of CAN.
3) Check CAN communication circuit between ESP®
control module and BCM for open, short and high
resistance.
Is each CAN communication circuit in good condition? Repair or replace the
CAN communication
line.
Go to Step 6.
6 CAN communication circuit check
1) Disconnect connectors of all control modules
communicating by means of CAN.
2) Check CAN communication circuit between control modules other than Step 5 for open, short and high
resistance.
Is each CAN communication circuit in good condition? Go to Step 7. Repair or replace the
CAN communication
line.
7 DTC check for ESP®
1) Connect connectors of disconnected control modules
communicating by means of CAN.
2) Disconnect each connector. •ECM
• Keyless start control module
• Combination meter
• Steering angle sensor
•BCM
3) Check DTC for ESP ®.
Is DTC U1140 detected? Check ESP
® control
module power and
ground circuit. If circuits
are OK, substitute a
known-good ESP ®
hydraulic unit / control
module assembly and
recheck. Check applicable
control module power
and ground circuit. If
circuit is OK, substitute
a known-good
applicable control
module and recheck.