2006 SUZUKI SWIFT ECM ground circuit

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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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5Main relay circuit check
1) Connect connectors to ECM with ignition switch turned
OFF.
2) Turn ignition switch to ON position.
3) Measure voltage between “E23-60” terminal of ECM connector and body ground.
Is voltage 0 – 1 V? Go to Step 7. Go to Step 6.
6 ECM ground circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from ECM.
3) Measure resistance between each “E23-31”, “C37-58”,
“C37-15” and “C37-30” terminals of ECM connector and
body ground.
Is resistance 1
Ω or less? Substitute a known-
good ECM and recheck.
“BLK/ORN” or “BLK”
wire is open or high
resistance circuit.
7 Main relay circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Using service wire, ground “E23-60” terminal of ECM connector and measure voltage between each “E23-1”
and “E23-16” terminals of ECM connector and body
ground.
Is voltage 10 – 14 V? Go to Step 11. Go to Step 8.
8 Main relay circuit check
1) Remove main relay (1) from individual circuit fuse box
No.1.
2) Check for proper connection to main relay connector at “BLK/YEL” and “BLK/RED” wire terminals.
3) If OK, measure resistance between each “E23-1” and “E23-16” wire terminals of ECM connector and “BLK/
RED” wire terminal of main relay connector.
Is resistance 1
Ω or less? Go to Step 9. “BLK/RED” wire is open
circuit or high resistance
circuit.
9 Main relay circuit check
1) Remove main relay from individual circuit fuse box No.1
with ignition swit ch turned OFF.
2) Measure voltage between “BLK/YEL” wire terminal of main relay connector and body ground.
Is voltage 10 – 14 V? Go to Step 10. “BLK/YEL” wire is open
circuit.
Step Action Yes No
1
I4RS0A110017-01

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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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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

Downloaded from www.Manualslib.com manuals search engine 1A-202 Engine General Information and Diagnosis:
6Fuel pump relay drive signal check
1) Measure voltage within 2 second after ignition switch is
turned ON.
Is voltage 0 – 1 V? Go to Step 7. Substitute a known-
good ECM and recheck.
7 Wire circuit check
1) Turn OFF ignition switch.
2) Detach fuel tank referring to “Fuel Tank Removal and
Installation in Section 1G”.
3) Disconnect connector from fuel pump.
4) Measure resistance between “PNK” wire terminal of fuel pump connector and vehicle body ground.
Is resistance infinity? Go to Step 8. “PNK” wire is shorted to
ground.
8 Fuel pump circuit check
1) Connect service wire between “E23-15” terminal of ECM
connector and vehicle body ground.
2) Turn ON ignition switch, measure voltage between “PNK” terminal at fuel pump connector and vehicle body
ground.
Is voltage 10 – 14 V? Go to Step 9. “PNK” wire is open
circuit.
9 Fuel pump circuit check
1) Turn OFF ignition switch.
2) Measure resistance between “BLK” wire terminal at fuel
pump connector and vehicle body ground.
Is resistance less than 5
Ω? Faulty fuel pump. “BLK” wire is open
circuit.
Step Action Yes No

Downloaded from www.Manualslib.com manuals search engine 1A-208 Engine General Information and Diagnosis:
11A/C compressor relay circuit check
1) Measure voltage between “E23-47” wire terminal of
ECM connector and vehicle body ground under following
conditions respectively.
Voltage between “E23-47” terminal of ECM
connector and ground
While engine running and A/C switch turned OFF: 10
– 14 V
While engine running, A/C and blower speed
selector switch turned ON: 0 – 1 V
Is check result satisfactory? Go to Step 12. Go to Step 13.
12 A/C compressor relay check
1) Check A/C compressor rela y referring to “Compressor
Relay Inspection in Sectio n 7B” or “Compressor Relay
Inspection in Section 7B”.
Is it in good condition? A/C compressor drive
circuit malfunction.
Replace A/C
compressor relay.
13 A/C compressor relay circuit check
1) Remove A/C compressor re lay with ignition switch
turned OFF.
2) Turn ON ignition switch, measure voltage between “BLK/ RED” wire terminal of A/C compressor relay connector
and vehicle body ground.
Is voltage 10 –14 V? Go to Step 14. “BLK/RED” wire is open
circuit.
14 A/C compressor relay check
1) Check A/C compressor rela y referring to “Compressor
Relay Inspection in Sectio n 7B” or “Compressor Relay
Inspection in Section 7B”.
Is it in good condition? “GRY” wire is open
circuit. If OK, substitute
a known-good ECM and
recheck.
Replace A/C
compressor relay.
Step Action Yes No

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.