2006 SUZUKI SWIFT ECM power & ground circuit check

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6Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at “E23- 35”, “E23-37” and “E23-34” terminals.
3) If OK, measure resistance between “GRN” wire terminal and each “BRN”, “RED” wire terminals of APP sensor
connector.
Is each resistance infinity? Go to Step 7. “GRN” wire is shorted to
“BRN” wire and/or
“RED” wire.
7 Wire harness check
1) Turn ON ignition switch.
2) Measure voltage between “E23-37” terminal of ECM
connector and engine ground.
Is voltage 0 V? Go to Step 8. “GRN” wire is shorted to
power circuit.
8 Ground circuit check
1) Connect connectors to ECM with ignition switch turned
OFF.
2) Measure resistance between “BLU” wire terminal of APP sensor connector and vehicle body ground.
Is resistance below 5
Ω? Go to Step 10. Go to Step 9.
9 Ground circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Check for proper connection of ECM connector at “E23- 52” terminal.
3) If OK, measure resistance between “E23-52” terminal of ECM connector and engine ground.
Is resistance below 5
Ω? “BLU” wire is open or
high resistance circuit.
Faulty ECM ground
circuit. If circuit is OK,
substitute a known-
good ECM and recheck.
10 APP sensor check
1) Check APP sensor (main) re ferring to “APP Sensor
Assembly Removal and Inst allation in Section 1C”.
Is output voltage within specified value? Substitute a known-
good ECM and recheck.
Replace APP sensor.
Step Action Yes No

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4ECM voltage check
1) Disconnect connector from APP sensor with ignition
switch turned OFF.
2) Check for proper connection to APP sensor at “RED”, “YEL” and “WHT” wire terminals.
3) If OK, measure voltage between “RED” wire terminal of APP sensor connector and vehicle body ground with
ignition switch turned ON.
Is voltage 4 – 6 V? Go to Step 6. Go to Step 5.
5 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at “E23- 34” terminal.
3) If OK, measure voltage between “E23-34” terminal of ECM connector and engine ground with ignition switch
turned ON.
Is voltage 0 V? Substitute a known-
good ECM and recheck.
“RED” wire is shorted to
power circuit.
6 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at “E23- 35”, “E23-36” and “E23-34” terminals.
3) If OK, measure resistance between “YEL” wire terminal and each “BRN”, “RED” wire terminals of APP sensor
connector.
Is each resistance infinity? Go to Step 7. “YEL” wire is shorted to
“BRN” wire and/or
“RED” wire.
7 Wire harness check
1) Turn ON ignition switch.
2) Measure voltage between “E23-36” terminal of ECM
connector and engine ground.
Is voltage 0 V? Go to Step 8. “YEL” wire is shorted to
power circuit.
8 Ground circuit check
1) Connect connectors to ECM with ignition switch turned
OFF.
2) Measure resistance between “WHT” wire terminal of APP sensor connector and vehicle body ground.
Is resistance below 5
Ω? Go to Step 10. Go to Step 9.
Step Action Yes No
"GRN"
"BLU"
"BRN"
"YEL"
"WHT"
"RED"
I4RS0B110048-01

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ECM Power and Ground Circuit CheckS7RS0B1104080
Wiring DiagramC37-3 to E23-1/16 EGR valve
(stepping motor No.2 coil)
20 – 31 Ω —
C37-18 to E23-1/16 EGR valv e (stepping motor No.4 coil)
C37-19 to E23-1/16 EGR valv e (stepping motor No.3 coil)
C37-46 to E23-29 Heater of HO2S-1 2 – 11 Ω—
C37-1 to E23-1/16 No.1 fuel injector 10.8 – 18.2 Ω —
E23-47 to E23-1/16 A/C compressor relay 160 – 240 Ω —
C37-60 to C37-59 Oil control valve 6 – 15 Ω —
E23-45 to E23-1/16 Throttle actuator control relay 160 – 240 Ω —
Terminals
CircuitStandard resistance Condition
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
BLK/RED
BLK/REDBLK/RED
BLK/YELBLK/YEL
BLK/YEL
GRN
BRN/WHT
12V
5VE23-1
E23-60
E23-16
WHT 2
4
11
6
3
12
13 14
7
1
16
17
89
15
10
5
WHT/REDE23-2
C37-58
C37-15C37-30
BLK/ORN
BLKBLKE23-31BLK
WHT
GRY/REDRED/BLK
ORN
C37-14C37-53
C37-55E23-54
REDE23-55
GRNBRN
BLU
REDYELWHT
E23-35E23-37E23-52
E23-51
E23-34E23-36
E23-50
LT GRN/REDLT GRN/BLKC37-45C37-44
C37-43
C37-54C37-40C37-42C37-41
RED
GRN
WHTBLK
ORN
BLK/WHTE23-29
I6RS0C110039-01
1. Main fuse box 7. Individual circuit fuse box No.1 13. A/C refrigerant pressure sensor (if equipped with A/C)
2. Ignition switch 8. “IG ACC” fuse14. APP sensor (main)
3. Main relay 9. “FI” fuse15. APP sensor (sub)
4. BCM (included in junction block assembly) 10. “RADIO” fuse 16. TP sensor (main)
5. “IG COIL” fuse 11. DLC17. TP sensor (sub)
6. ECM 12. MAP sensor

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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

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10Main relay check
1) Check main relay referring to “Main Relay, Fuel Pump
Relay and Starting Motor Control Relay Inspection in
Section 1C”.
Is main relay in good condition? “BRN/WHT” wire is
open or high resistance
circuit.
Replace main relay.
11 Sensor power source circuit check
1) Connect connectors to ECM with ignition switch turned
OFF.
2) Turn ON ignition switch, measure each voltage between “C37-14”, “E23-35”, “E23-34” and “C37-43” terminals of
ECM connector and vehicle body ground.
Is each voltage 4 – 6 V? ECM power and ground
circuit is in good
condition.
Go to Step 12.
12 Sensor power source circuit check
1) Disconnect connectors from ECM, TP sensor, APP
sensor, MAP sensor and A/C refrigerant pressure sensor
(if equipped with A/C) with i gnition switch turned OFF.
2) Measure each resistance between “C37-14”, “E23-35”, “E23-34” and “C37-43” terminals of ECM connector and
vehicle body ground.
Is each resistance infinity? Check internal short
circuit of TP sensor,
APP sensor, MAP
sensor and/or A/C
refrigerant pressure
sensor (if equipped with
A/C).
“GRY/RED” wire is
shorted to ground
circuit.
Step Action Yes No

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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 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.

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7Radiator cooling fan No. 2 wire circuit check
1) Turn ON ignition switch.
2) Measure voltage between “BLU/BLK” wire terminal of
disconnected radiator cooling fan control relay No. 2
connector and vehicle body ground.
Is voltage 0 V? Go to Step 8. “BLU/BLK” wire is
shorted to power supply
circuit.
8 Radiator cooling fan control No. 2 check
1) Connect radiator cooling fan control relay No. 2 to
individual circuit fuse box No.1 with ignition switch
turned OFF.
2) Run engine when ECT is over 102.5 °C, 216.5 °F.
3) Measure voltage between vehicle body ground and “BLU/BLK” wire terminal of disconnected radiator
cooling fan motor connector.
Is voltage 10 – 14 V? Go to Step 10. Go to Step 9.
9 Radiator cooling fan control relay No.2 check
1) Remove radiator cooling fan control relay No.2 with
ignition switch turned OFF.
2) Check radiator cooling fan control relay No.2 referring to “Radiator Cooling Fan Relay Inspection in Section 1F”.
Is it in good condition? “BLU/BLK” wire is open
or high resistance
circuit.
Faulty radiator cooling
fan control relay No.2.
10 Radiator cooling fan No. 3 wire circuit check
1) Remove radiator cooling fan control relay No.3 with
ignition switch turned OFF.
2) Measure resistance between vehicle body ground and “BLK” wire terminal of disconnected radiator cooling fan
control relay No. 3 connector in individual circuit fuse
box No.1.
Is resistance below 1
Ω? Go to Step 11. “BLK” wire is open or
high resistance circuit.
11 Radiator cooling fan control No. 3 check
1) Connect radiator cooling fan control relay No. 3 to
individual circuit fuse box No.1 with ignition switch
turned OFF.
2) Run engine when ECT is over 102.5 °C, 216.5 °F.
3) Measure resistance between vehicle body ground and “BLU/WHT” wire terminal of disconnected radiator
cooling fan motor connector.
Is resistance below 2
Ω? Go to Step 13. Go to Step 12.
12 Radiator cooling fan control relay No. 3 check
1) Remove radiator cooling fan control relay No.3 with
ignition switch turned OFF.
2) Check radiator cooling fan control relay No.3 referring to “Radiator Cooling Fan Relay Inspection in Section 1F”.
Is it in good condition? “BLU/WHT” wire is open
or high resistance
circuit.
Faulty radiator cooling
fan control relay No.3.
13 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.
Step
Action YesNo

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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 )