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

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DTC P0620: Generator Control CircuitS7RS0B1104057
System and Wiring Diagram
Generator Control System Description
Refer to “Generator Control System Description”.3
Wire circuit check
1) Disconnect starting motor control relay in individual
circuit fuse box No.1 with ignition switch turned OFF.
2) Check for proper connection to starting motor control relay at “RED/WHT”, “RED”, “WHT”, “YEL” (for A/T
model) and “YEL/GRN” (for M/T model) wire terminals.
3) Disconnect connector from starting motor.
4) Measure voltage between “C37-48” terminal of ECM connector and vehicle body ground with ignition switch
turned ON.
Is voltage 0 – 1 V? Go to Step 4. For A/T model, “YEL” or
“YEL/GRN” wire is
shorted to power circuit.
For M/T model, “YEL/
GRN” wire is shorted to
power circuit.
If wires are OK,
substitute a known good
ECM and recheck.
4 Wire circuit check
1) Measure voltage between “RED/WHT” wire terminal of
starting motor control relay connector and vehicle body
ground with ignition switch turned ON.
Is voltage 0 – 1 V? Check starting motor
control relay. If OK,
substitute a known-
good ECM and recheck.
Faulty ignition switch,
check ignition switch
referring to “Ignition
Switch Inspection in
Section 9C”.
If ignition switch is OK,
check for short circuit
between ignition switch
and starting motor
control relay to power
circuit.
Step Action Yes No
IG
L
C
FR
E 4
2
BRN/BLKC37-8
BLU/YELC37-28
B
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 1
3 5
I5RS0C110013-01
1. Generator
3. Field coil 5. Ignition switch
2. IC regulator 4. ECM 6. Charge lamp

Downloaded from www.Manualslib.com manuals search engine 1A-138 Engine General Information and Diagnosis:
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool to DLC
2) Turn ON ignition switch and clear DTC.
3) Make sure that all accessory switches are tuned OFF.
4) Start engine and warm it up to normal operating temperature (ECT approx. 90 – 95 °C, 193 – 203 °F).
5) Turn ON the followi ng accessory switches.
• Head light switch.
• Blower motor switch (max position).
• Rear defogger switch.
6) Increase engine speed to 4000 rpm and keep it for 10 sec or more.
7) Decrease engine speed to idle.
8) 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.

DTC detecting condition Trouble area
• Battery voltage is higher than specification even through generator control is maximum regulation (duty 100%).
• Battery voltage is lower than specification even through generator control is minimum regulation (duty 0%) and electric
load is less than 15 A.
(1 driving cycle detection logic but MIL does not light up) • Generator and/or its circuit
• Electric load current sensor
•ECM
• Generator drive belt
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 Generator drive belt check
1) Check generator drive belt tension referring to “Water
Pump / Generator Drive Belt Tension Inspection and
Adjustment in Section 1J”.
Is check result satisfactory? Go to Step 3.
Adjust or replace
generator drive belt.

Downloaded from www.Manualslib.com manuals search engine 1A-140 Engine General Information and Diagnosis:
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool to DLC.
2) Turn ON ignition switch and clear DTC.
3) Make sure that all accessory switch is tuned OFF.
4) Start engine and warm it up to normal operating temperature (ECT approx. 90 – 95 °C, 193 – 203 °F).
5) Turn ON following accessory switch. • Head lights switch.
• Blower motor switch (max position).
• Rear defogger switch.
6) Increase engine speed to 4000 rpm and keep it for 10 sec. or more.
7) Decrease engine speed to idle.
8) 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 Generator control circuit check
1) Disconnect connector from generator and ECM with
ignition switch turned OFF.
2) Check for proper connection of wire terminal to generator connector and to ECM connector.
3) If connections are OK, check generator control (generator “C” terminal) circuit and field coil monitor
(generator “FR” terminal) circuit for the following.
• Resistance of each generato r control wire and field
coil monitor wire between generator connector and
ECM connector is less than 1 Ω (continuity check)
• Resistance between generator control wire and field coil monitor wire of generator connector is infinity
(insulation check)
• Resistance between each generator control wire and field coil monitor wire of generator connector and
vehicle body ground is infinity (ground circuit short
check)
• Voltage between each generator control wire and field
coil monitor wire of generator connector and vehicle
body ground is 0 V with ignition switch tuned ON
(power circuit short check)
Are they in good condition? Go to Step 3.
Repair or replace
defective wire.
3 Generator check
1) Check for generator output referring to “Generator Test
(Undercharged Battery Check) in Section 1J” and
“Generator Inspection in Section 1J”.
Is check result satisfactory? Substitute a known
good ECM and recheck.
Repair or replace
generator.

Downloaded from www.Manualslib.com manuals search engine 1A-142 Engine General Information and Diagnosis:
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 Electric load current sensor power and ground circuit
check
1) Disconnect connector from electric load current sensor.
2) Check electric load current sensor circuit for the
following.
• Voltage between “BLK/WHT” wire terminal of electric load current sensor conn ector and vehicle body
ground is 10 – 14 V with ignition switch turned ON
• Resistance between “BLK /ORN” wire terminal of
electric load current sensor connector and vehicle
body ground is less than 2 Ω
Are they in good condition? Go to Step 3.
Repair or replace
defective wire.
3 Electric load current sensor output circuit check
1) Disconnect connectors from ECM.
2) Check electric load current sensor circuit for the
following.
• Resistance between “PNK/BLU” wire terminal of electric load current sensor connector and “C37-23”
terminal of ECM connector is less than 2 Ω
• Resistance between “PNK/BLU” wire terminal of electric load current sensor connector and vehicle
body ground is infinity
• Voltage between “PNK/BLU” wire terminal of electric load current sensor conn ector and vehicle body
ground is 0 V with ignition switch turned ON
Are they in good condition? Go to Step 4.
Repair or replace
defective wire.
4 Electric load current sensor check
1) Check for electric load current sensor output referring to
“Electric Load Current Sensor On-Vehicle Inspection in
Section 1C”.
Is check result satisfactory? Substitute a known-
good ECM and recheck.
Faulty electric load
current sensor.

Downloaded from www.Manualslib.com manuals search engine 1A-144 Engine General Information and Diagnosis:
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.

DTC P1603: TCM Trouble Code DetectedS7RS0B1104061
Wiring Diagram
DTC Detecting Condition
When ECM receives a trouble code from TCM, which indicates that some problem occurred in sensor circuits and its
calculated values used for operations such as idle speed control, engine power control, and so on by TCM, ECM sets
DTC P1603. (TCM outputs the trouble code to ECM when TCM can not compute the engine control signal due to
malfunctions of sensor circuits used for gear shift control.) Step Action Yes No
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2. Go to “Engine and
Emission Control
System Check”.
2 Battery voltage supply circuit check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) With engine running, measure voltage between “E23-2” terminal of ECM connector and engine ground.
Is voltage 10 – 14 V? Poor “E23-2”
connection or
intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
If wire and connections
are OK, substitute a
known-good ECM and
recheck.“RADIO” fuse blown,
“WHT” or “WHT/RED”
wire is circuit open or
short circuit.
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
1
RED
WHT
C37-13
C37-12
RED
WHTC34-7
C34-17
2
I6RS0C110026-01
1. ECM
2. TCM (for A/T model)

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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.

DTC P1674: CAN Communication (Bus Off Error)S7RS0B1104062
Wiring Diagram
ESP ® model
Step Action Yes No
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2. Go to “Engine and
Emission Control
System Check”.
2 DTC check
1) Check DTC of TCM referring to “DTC Check in Section
5A”.
Is there any DTC(s)? Go to applicable DTC
diag. flow.
Substitute a known-
good ECM and recheck.
[F]
E85
161
15
2
3
4
5
6
7
8
9
10
11
12
13
14
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
3233
34
35
36
37
38
39
40
41
42
43
44
45
46
47
[D] 12345678910
11
141516
36 34 33 32 31 30 29 24 23
37
181920
G49
[A]
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
[C]G28
1234567
8
910
11
1213141516
1718
19
20
212223242526272829303132
[E] G54
109 321
[B]
G37E46
1234567 1234567
8910
11
8910
11
121314 121314
1516171819202122
4
6 1
2
3
REDWHT
REDWHT
REDWHT
REDWHT
REDWHT
E23-3E23-18
E85-42E85-46
E85-13E85-44
E46-1E46-2
G37-4G37-2
REDWHT
REDWHTG49-19G49-18
5
7
WHTG54-9REDG54-10
G28-8G28-10
G28-7REDG28-9WHT
I7RS0B110014-02
[A]: ECM connector (viewed from harness side)
1. ECM
[B]: BCM connector (viewed from harness side) 2. ESP® control module
[C]: Combination meter connector (viewed from harness side) 3. BCM
[D]: Keyless start control module connector (vie wed from harness side) 4. Steering angle sensor
[E]: Steering angle sensor connector (viewed from harness side) 5. Combination meter
[F]: ESP ® control module connector (viewed from terminal side) 6. Keyless start control module
7. CAN junction connector

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-147
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 Control module connector check
1) Check connection of connectors of all control module/
sensor communicating by means of CAN.
2) Recheck DTC.
Is DTC P1674 detected? 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 module/sensor
communicating by means of CAN.
3) Check CAN communication circuit between control module/sensor for open, short and high resistance.
Is each CAN communication circuit in good condition? Go to Step 4.
Repair circuit.
4 DTC check of ECM
1) Turn ignition switch to OFF position.
2) Connect connectors of di sconnected control module/
sensor communicating by means of CAN.
3) Disconnect connector from any one of control module/ sensor other than BCM and ECM.
4) Recheck ECM for DTC.
Is DTC P1674 detected? Disconnect connectors
of control module/
sensor other than the
one whose connector is
disconnected in Step 3)
one by one and check
that DTC P1674 is
detected by ECM each
time connector is
disconnected. When
DTC P1674 is not
detected by ECM while
checking in this way, go
to description under
“NO” below. If DTC
P1674 is detected by
ECM, go to Step 5.Check power and
ground circuit of control
module disconnect in
Step 3). If circuit is OK,
substitute a known-
good control module
disconnected in Step 3)
and recheck.
5 DTC check of ECM
1) Substitute a known-good BCM and recheck ECM for
DTC.
Is DTC P1674 detected? Substitute a known-
good ECM and recheck.
End.

Downloaded from www.Manualslib.com manuals search engine 1A-148 Engine General Information and Diagnosis:
DTC P1676: CAN Communication (Reception Error for TCM)S7RS0B1104064
Wiring Diagram
Refer to “DTC P1674: CAN Communication (Bus Off Error)”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC by using scan tool.
3) Start engine and run it for 1 min. or more.
4) 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.

DTC detecting condition Trouble area
Reception error of communication data for TCM is
detected for longer than specified time continuously.
(1 driving detection logic) •ECM
• TCM (for A/T model)
• CAN communication circuit
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 Check CAN communication error for ECM
1) Check ECM for DTC.
Is there DTC P1674? Go to “DTC P1674:
CAN Communication
(Bus Off Error)”.
Go to Step 3.
3 ECM and TCM connector check
1) Check for proper connection at each ECM and TCM
connector terminals with ignition switch turned OFF.
2) If connections are OK, recheck ECM for DTC with engine running.
Is there DTC P1676? Go to Step 4.
Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
4 DTC check in TCM
1) Check DTC P1774 in TCM.
Is it indicated? Go to “DTC P1774:
CAN Communication
Bus Off in Section 5A”.
Go to Step 5.
5 CAN communication circuit check
1) Disconnect connectors of ECM and TCM.
2) Check CAN communication circuit between ECM and
TCM connectors for open, short and high resistance.
Is each CAN communication circuit in good condition? Go to Step 6.
Repair circuit.
6 DTC check of ECM
1) Connect connectors to ECM and TCM with ignition
switch turned.
2) Check ECM for DTC.
Does ECM communicate with control module other than
TCM (i.e. DTC P1678 and/or P1685 are not detected)? Substitute a known-
good TCM and recheck.
Substitute a known-
good ECM and recheck.

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DTC P1678: CAN Communication (Reception Error for BCM)S7RS0B1104065
Wiring Diagram
Refer to “DTC P1674: CAN Communication (Bus Off Error)”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC by using scan tool.
3) Start engine and run it for 1 min. or more.
4) 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.

DTC detecting condition Trouble area
Reception error of communication data for BCM is
detected for longer than specified time continuously.
(1 driving detection logic but MIL does not light up) •ECM
• ABS/ESP®
control module
•BCM
• CAN communication circuit
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 CAN communication error check for ECM
1) Check ECM for DTC.
Is there DTC P1674? Go to “DTC P1674:
CAN Communication
(Bus Off Error)”.
Go to Step 3.
3 ECM, ABS control module and BCM connector check
1) Check for proper connecti on at each ECM, ABS/ESP®
control module and BCM connector terminals with
ignition switch turned OFF.
2) If connections are OK, recheck ECM for DTC with engine running.
Is there DTC P1678? Go to Step 4.
Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
4 DTC check in BCM
1) Check DTC U1073 in BCM.
Is it indicated? Go to “DTC U1073 (No.
1073): Control Module
Communication Bus Off
in Section 10B”.Go to Step 5.
5 DTC check of ABS/ESP ® control module
1) Check DTC U1073 in ABS/ESP ® control module.
Is it indicated? Go to “DTC U1073:
Control Module
Communication Bus Off
in Section 4E”.Go to Step 6.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-153
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 Throttle actuator circuit check
1) Disconnect connectors from electric throttle body and
ECM with ignition switch turned OFF.
2) Check for proper connection of electric throttle body and ECM connectors at “LT GRN/RED” wire, “LT GRN/BLK”
wire. “C37-45” and “C37-44” terminals.
3) Turn ON ignition switch.
4) Measure voltage between “LT GRN/RED” wire terminal of electric throttle body connector and engine ground,
between “LT GRN/BLK” wire terminal of electric throttle
body connector and engine ground.
Is voltage 0 V? Go to Step 3.
“LT GRN/RED” wire
and/or “LT GRN/BLK”
wire is shorted to power
circuit.
3 Throttle actuator circuit check
1) Turn OFF ignition switch.
2) Measure resistance between “LT GRN/RED” wire
terminal of electric throttle body connector and engine
ground, between “LT GRN/BLK” wire terminal of electric
throttle body connector and engine ground.
Is resistance infinity? Go to Step 4.
“LT GRN/RED” wire
and/or “LT GRN/BLK”
wire is shorted to
ground circuit.
4 Throttle actuator circuit check
1) Check throttle actuator refe rring to “Throttle Actuator
Performance Check” under “Electric Throttle Body
Assembly On-Vehicle Inspection in Section 1C”.
Is check result satisfactory? Substitute a known-
good ECM and recheck.
Replace electric throttle
body
"GRN"
"RED"
"WHT"
"BLK"
"LT GRN/BLK"
"LT GRN/RED"
I4RS0B110022-02