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

Downloaded from www.Manualslib.com manuals search engine 1A-174 Engine General Information and Diagnosis:
DTC Confirmation Procedure
DTC P2227:
WARNING!
• When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out by 2 persons, a driver and a tester, on a level road.

1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool and warm up
engine to normal operating temperature.
3) Check DTC and pending DTC by using scan tool.
DTC P2228 / P2229: 1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch, clear DTC by using scan tool and run engine for 1 min.
3) Check DTC.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.

Step Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Is DTC P2227 set? Go to Step 3.Substitute a known-
good ECM and recheck.
3 MAP sensor check
1) Check MAP sensor and its circuit referring to “DTC
P0107: Manifold Absolute Pressure / Barometric
Pressure Circuit Low Input” and/or “DTC P0108:
Manifold Absolute Pressure / Barometric Pressure
Circuit High Input”.
Is check result satisfactory? Substitute a known-
good ECM and recheck.
MAP sensor or its circuit
malfunction.

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Inspection of ECM and Its CircuitsS7RS0B1104079
ECM and its circuits can be checked by measuring voltage, pulse signal and resistance with special tool connected.
CAUTION!
ECM cannot be checked by itself. It is strictly prohibited to connect voltmeter or ohmmeter to ECM
with ECM connectors disconnected from it.

Voltage Check
1) Remove ECM (1) from its bracke t referring to “ECM Removal and Installation in Section 1C”.
2) Connect special tool between EC M and ECM connectors securely.
Special tool
(A): 09933–06320
3) Check voltage and/or pulse signal us ing voltmeter (2) and oscilloscope (3).
NOTE
• As each terminal voltage is affected by battery voltag e, confirm that it is 11 V or more when ignition
switch is turned ON.
• Voltage with asterisk (*) cannot be measured with voltmeter because it is pulse signal. Use oscilloscope for its check if necessary.
• Before this inspection, be sure to read the “Precautions of ECM Circuit Inspection”.

Viewed from harness side
1
2
3 (A)
I5RS0C110023-01
E23
C37
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
I4RS0A110055-01

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Circuit Description
When the ignition switch is turned ON, the main relay turns ON (the contact point closes) and the main power is
supplied to ECM.
Troubleshooting
NOTE
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special
tool to ECM and/or the ECM connectors referri ng to “Inspection of ECM and Its Circuits”.

StepAction YesNo
1 Circuit fuse check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection to ECM connector at “E23- 2”, “E23-29”, “E23-60”, “E23-1”, “E23-16”, “E23-31”,
“C37-58”, “C37-15” and “C37-30” terminals.
3) If OK, check “RADIO” fuse and “IG COIL” fuse for blowing.
Are “RADIO” fuse and “IG COIL” fuse in good condition? Go to Step 2.
Replace fuse (s) and
check for short in
circuits connected to
fuse(s).
2 Power supply circuit check
1) Measure voltage between “E23-2” terminal of ECM
connector and body ground.
Is voltage 10 – 14 V? Go to Step 3.
“WHT/RED” or “WHT”
wire is open circuit.
3 Ignition signal check
1) Turn ignition switch to ON position.
2) Measure voltage between “E23-29” terminal of ECM
connector and body ground.
Is voltage 10 – 14 V? Go to Step 4.
“BLK/WHT” or “GRN”
wire is open circuit.
4 Main relay circuit check
1) Turn ignition switch to OFF position.
2) Check “FI” fuse (1) in indivi dual circuit fuse box No.1 for
blowing.
3) If OK, measure voltage between “E23-60” terminal of ECM connector and body ground.
Is voltage 10 – 14 V? Go to Step 5.
Go to Step 9.
1
I4RS0A110016-01

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-199
Troubleshooting
NOTE
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special
tool to ECM and/or the ECM connectors referri ng to “Inspection of ECM and Its Circuits”.

StepAction YesNo
1 Fuel injector check for operating sound
1) Using sound scope, check each injector for operating
sound at engine cranking.
Do all 4 injector ma ke operating sound? Fuel injectors circuit is
in good condition.
Go to Step 2.
2 Fuel injector resistance check
1) Disconnect connectors from fuel injectors with ignition
switch turned OFF.
2) Check for proper connection to fuel injector at each terminals.
3) If OK, check all 4 fuel inject ors for resistance referring to
“Fuel Injector On-Vehicle Inspection in Section 1G”.
Are all injectors in good condition? Go to Step 3.
Faulty fuel injector.
3 Fuel injector insulation resistance check
1) Check that there is insulation between each fuel injector
terminal and engine ground.
Is there insulation? Go to Step 4.
Faulty fuel injector.
4 Fuel injector power supply check
1) Measure voltage between each “BLK/RED” wire terminal
of fuel injector connector and engine ground with ignition
switch turned ON.
Is voltage 10 – 14 V? Go to Step 5.
“BLK/RED” wire is open
or shorted to ground
circuit.
If it is in good condition,
go to “ECM Power and
Ground Circuit Check”.
5 Wire circuit check
1) Turn OFF ignition switch.
2) Disconnect connectors from ECM.
3) Measure resistance between each “BLU/YEL”, “BLU/
WHT”, “BLU/RED”, “BLU/ORN” wire terminal of fuel
injector connector and vehicle body ground.
Is resistance infinity? Go to Step 6.
“BLU/YEL”, “BLU/WHT”,
“BLU/RED” and/or
“BLU/ORN” wire(s) are
shorted to ground.
6 Wire circuit check
1) Measure voltage between each “BLU/YEL”, “BLU/WHT”,
“BLU/RED”, “BLU/ORN” wire terminal of fuel injector
connector and vehicle body ground with ignition switch
turned ON.
Is voltage 0 V? Go to Step 7.
“BLU/YEL”, “BLU/WHT”,
“BLU/RED” and/or
“BLU/ORN” wire(s) are
shorted to power supply
circuit.
7 Fuel injector drive signal check
1) Connect connectors to each fuel injector and ECM with
ignition switch turned OFF.
2) Turn ON ignition switch.
3) Measure voltage between each “C37-1”, “C37-2”, “C37- 16”, “C37-17” terminal of ECM connector and vehicle
body ground.
Is voltage 10 – 14 V? Check fuel injector
referring to “Fuel
Injector Inspection in
Section 1G”.
If check result is
satisfactory, substitute a
known-good ECM and
recheck.
“BLU/YEL”, “BLU/WHT”,
“BLU/RED” and/or
“BLU/ORN” wire(s) are
open circuit.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-201
Troubleshooting
NOTE
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special
tool to ECM and/or the ECM connectors referri ng to “Inspection of ECM and Its Circuits”.

StepAction YesNo
1 Fuel pump control system check for operation
Is fuel pump heard to operate 2 sec. after ignition switch is
turned ON? Fuel pump circuit is in
good condition.
Go to Step 2.
2 Fuel pump relay po wer supply check
1) Disconnect fuel pump relay from individual circuit fuse box No.1 with ignition switch turned OFF.
2) Check for proper connection to fuel pump relay at each terminal.
3) If OK, turn ON ignition switch, measure voltage between “BLK/WHT” wire terminal of fuel pump relay connector
and engine ground.
Is voltage 10 – 14 V? Go to Step 3.
“BLK/WHT” wire is open
or shorted to ground
circuit.
3 Fuel pump relay po wer supply check
1) Turn ON ignition switch, measure voltage between “BLK/ RED” wire terminal of fuel pump relay connector and
engine ground.
Is voltage 10 – 14 V? Go to Step 4.
“BLK/RED” wire is open
circuit.
4 Fuel pump relay check
1) Check fuel pump relay referring to “Main Relay, Fuel
Pump Relay and Starting Moto r Control Relay Inspection
in Section 1C”.
Is relay in good condition? Go to Step 5.
Faulty relay.
5 Fuel pump relay drive signal check
1) Connect fuel pump relay to individual circuit fuse box
No.1.
2) Connect voltmeter between “E23-15” terminal of ECM connector and vehicle body ground.
3) Measure voltage 2 second after ignition switch is turned ON.
Is voltage 10 – 14 V? Go to Step 6.
“GRN/WHT” wire is
open circuit or shorted
to ground circuit.
I2RH01110132-01

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Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• When A/C evaporator outlet air temp. is below 2.5 °C (36.5 °F), A/C remains OFF (“E23-47” terminal
voltage becomes 10 – 14 V). This condition is not abnormal.

Step Action YesNo
1 Reception data check from BCM
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Check DTC for reception data from BCM.
Is there DTC P1678? Go to applicable DTC
diag. flow.
Go to Step 2.
2 A/C switch signal circuit check
1) Start engine and select “DATA LIST” mode on scan tool.
2) Check A/C switch signal under following conditions
respectively.
A/C switch signal
Engine running, A/C switch OFF: OFF
Engine running, A/C switch ON and blower speed
selector turned 1st position or more: ON
Is check result satisfactory? Go to Step 3. Check A/C switch
circuit.
3 DTC check of ECT sensor circuit
1) Check ECM for DTC of ECT sensor circuit.
Is there DTC P0116, DTC P0117 or DTC P0118? Go to applicable DTC
diag. flow.
Go to Step 4.
4 Radiator cooling fan control system check
Is radiator cooling fan started when A/C and blower speed
selector switch are turned ON with engine running? Go to Step 10. Go to Step 5.
5 Radiator cooling fan control circuit check
1) Check DTC with scan tool.
Is DTC P0480 displayed? Go to “DTC P0480: Fan
1 (Radiator Cooling
Fan) Control Circuit”.
Go to Step 6.

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6A/C evaporator outlet air temp. sensor check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection to “E23-57” and “E23-54” wire terminals of ECM connector.
3) If OK, measure resistance between “E23-57” and “E23- 54” wire terminals of ECM connector.
Evaporator temp. sensor resistance
At 0 °C: 6.3 – 6.9 k Ω
At 25 °C: 1.8 – 2.2 k Ω
Is resistance within specification? Go to Step 7. Faulty A/C evaporator
outlet air temp. sensor
or its circuit.
7 DTC check of A/C refrigerant pressure sensor circuit
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Check ECM for DTC of A/C refrigerant pressure sensor circuit.
Is there DTC P0532 or DTC P0533? Go to applicable DTC
diag. flow.
Go to Step 8.
8 A/C refrigerant pressure sensor voltage check
1) Check A/C refrigerant pressure sensor voltage referring
to “Inspection of ECM and Its Circuits”.
Is voltage within specified value? Go to Step 9. Check amount of
refrigerant. If OK,
replace A/C refrigerant
pressure sensor.
9 Radiator cooling fan check
1) Check radiator cooling fan referring to “Radiator Cooling
Fan Motor On-Vehicle Inspection in Section 1F”.
Is check result satisfactory? Radiator cooling fan
drive circuit malfunction.
If circuit is OK, go to
St ep 6 .
Replace radiator cooling
fan motor.
10 A/C compressor control system check
Is A/C compressor started when A/C and blower speed
selector switch are turned ON with engine running? A/C system is in good
condition.
Go to Step 11.
Step Action Yes No
7
6
5
4
3
2
1
10
20 30
40 50
0
10
2030
60 70 80
ResistanceTemperatureI3RB0A110053-01

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Electric Load Signal Circuit CheckS7RS0B1104085
Wiring Diagram
Troubleshooting
NOTE
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special
tool to ECM and/or the ECM connectors referri ng to “Inspection of ECM and Its Circuits”.

BLK/WHT
BLK/RED
WHT
BRN/WHT
12V5V
11
BLK/YELBLK/YEL
BLK/YEL
BLKBLKBLK
BLK/ORN
10
18
17
BLU/WHT
15
WHTRED
43
YEL
5
13
BLK/WHT
BLKBLK/YEL
GRN
WHT
/BLU
BLU
16
2
6
7
12
8
9
BLK
WHT
RED
E23-29
E23-60
E23-1E23-16
E23-9
E23-3E23-18
C37-58C37-15
E23-31C37-30
BLK/RED
[A]
[B]
E23 C37
34
1819
567
10
11
17
20
47 46
495051
2122
52 16
25 9
24
14
29
5557 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
4042 39 38
44
45 43 41 331
1213
238
34
1819
567
10
11
17
20
47 46
495051
2122
52 16
25 9
24
14
29
5557 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
4042 39 38
44
45 43 41 331
12
13
238
1
14
I7RS0B110016-01
[A]: Manual A/C model
6. Ignition switch13. Blower motor
[B]: Auto A/C model 7. Junction block assembly14. HVAC control module
1. Main fuse 8. “IG COIL” fuse15. Blower speed selector
2. Individual circuit fuse box No.1 9. “IG2 SIG” fuse16. Electric load (rear defogger signal and headlight signal), etc.
3. “IG ACC” fuse 10. ECM17. BCM
4. “FI” fuse 11. Main relay18. ABS/ESP® control module
5. “HTR FAN” fuse 12. Blower motor relay
StepAction YesNo
1 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ON ignition switch and check DTC.
Is there any DTS(s) related to CAN? Go to applicable DTC
diag. flow.
Go to Step 2.

Downloaded from www.Manualslib.com manuals search engine 1A-212 Engine General Information and Diagnosis:
Troubleshooting
WARNING!
Keep hands, tools, and clothing away from engine cooling fan to help prevent personal injury. This fan
is electric and can come on whether or not the engi ne is running. The fan can start automatically in
response to the ECT sensor with the ig nition switch at the “ON” position.

NOTE
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special
tool to ECM and/or the ECM connectors referri ng to “Inspection of ECM and Its Circuits”.

StepAction YesNo
1 Is there DTC(s) of ECT sensor circuit (DTC P0116 / P0117 /
P0118) and/or radiator cooling fan circuit (DTC P0480)? Go to corresponding
DTC flow.Go to Step 2.
2 Low speed radiator cooling fan control circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Start engine and select “DATA LIST” mode on scan tool.
3) Warm up engine until coolant temp. is 97.5 °C, 207.5 °F
or higher and A/C switch turns OFF (if equipped with A/
C). (If engine coolant temp. dose not rise, check engine
cooling system or ECT sensor.)
Is radiator cooling fan started at low speed when engine
coolant temp. reached above temp.? Radiator cooling fan low
speed control system is
in good condition.
Perform from Step 2 to
Step 8 in DTC P0480
diag. flow. If OK, Go to
Ste p 3.
3 Radiator cooling fan control check
1) Disconnect radiator cooling fan control relays No. 2, and
No. 3 from individual circuit fuse box No.1 with ignition
switch turned OFF.
2) Run engine when ECT is over 97.5 °C, 207.5 °F.
3) Measure voltage between vehicle body ground and “BLU/RED” wire terminal of disconnected radiator
cooling fan motor connector.
Is voltage 10 – 14 V? Go to Step 4.
“BLU/RED” wire is open
or high resistance
circuit.
4 Check radiator cooling fan wire circuit check
1) Turn ignition switch to OFF position.
2) Measure resistance between “BLK” wire terminal of
disconnected radiator coolin g fan motor connector and
vehicle body ground.
Is resistance below 1
Ω? Go to Step 5. “BLK” wire is open or
high resistance circuit.
5 Radiator cooling fan check
1) Check radiator cooling fan referring to “Radiator Cooling
Fan Motor On-Vehicle Inspection in Section 1F”.
Is it in good condition? Substitute a known-
good ECM and recheck.
Faulty radiator cooling
fan.

Downloaded from www.Manualslib.com manuals search engine 1A-214 Engine General Information and Diagnosis:
Troubleshooting
WARNING!
Keep hands, tools, and clothing away from engine cooling fan to help prevent personal injury. This fan
is electric and can come on whether or not the engi ne is running. The fan can start automatically in
response to the ECT sensor with the ig nition switch at the “ON” position.

NOTE
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special
tool to ECM and/or the ECM connectors referri ng to “Inspection of ECM and Its Circuits”.

StepAction YesNo
1 Is there DTC(s) of ECT sensor circuit (DTC P0116 / P0117 /
P0118) and/or radiator cooling fan circuit (DTC P0480)? Go to corresponding
DTC flow.Go to Step 2.
2 Low speed radiator cooling fan control circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Start engine and select “DATA LIST” mode on scan tool.
3) Warm up engine until coolant temp. is 97.5 °C, 207.5 °F
or higher and A/C switch turns OFF (if equipped with A/
C). (If engine coolant temp. dose not rise, check engine
cooling system or ECT sensor.)
Is radiator cooling fan started at low speed when engine
coolant temp. reached above temp.? Go to Step 3.
Perform from Step 2 to
Step 5 in “Radiator
Cooling Fan Low Speed
Control System Check”.
3 High speed radiator cooling fan control circuit check
1) Start engine and select “DATA LIST” mode on scan tool.
2) Warm up engine until coolant temp. is 102.5 °C, 216.5 °F
or higher and A/C switch turns OFF (if equipped with A/
C). (If engine coolant temp. dose not rise, check engine
cooling system or ECT sensor.)
Is radiator cooling fan started at high speed when engine
coolant temp. reached above temp? Radiator cooling fan
control system is in
good condition.
Perform from Step 9 to
Step 14 in DTC P0480
diag. flow.
If OK, Go to Step 4.
4 Radiator cooling fan control No. 2 and No. 3 check
1) Run engine when ECT is over 102.5 °C, 216.5 °F.
2) Measure voltage between vehicle body ground and “E23-48” terminal of ECM connector.
Is voltage lower than 1.5 V? Go to Step 5.
Faulty ECM.
5 Radiator cooling fan No. 2 wire circuit check
1) Remove radiator cooling fan control relay No.2 with
ignition switch turned OFF.
2) Measure voltage between “GRY” wire terminal of disconnected radiator cooling fan control relay No. 2
connector and vehicle body ground.
Is voltage 10 – 14 V? Go to Step 6.
“GRY” wire is open or
high resistance circuit.
6 Radiator cooling fan No. 2 wire circuit check
1) Disconnect connector from radiator cooling fan motor
with ignition swit ch turned OFF.
2) Measure resistance between “BLU/BLK” wire terminal of disconnected radiator cooling fan control relay No. 2
connector and vehicle body ground.
Is resistance infinity? Go to Step 7.
“BLU/BLK” wire is
shorted to ground
circuit.