2006 SUZUKI SWIFT ECM power & ground circuit check

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DTC P0123: Throttle / Pedal Position Sensor / Switch “A” (Main) Circuit HighS7RS0B1104030
Wiring Diagram
Refer to “DTC P0122: Throttle / Pedal Position Sensor / Switch “A” (Main) Circuit Low”.
DTC Detecting Condition and Trouble Area
NOTE
When DTC P0123 and P0223 are indicated together, it is possible that “RED” wire shorted to power
circuit and/or “BLK” wire open.

DTC Confirmation Procedure
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Keep the accelerator pedal at idle position for 2 seconds.
4) Keep the accelerator pedal at fully depressed position for 2 seconds.
5) Repeat Step 3) and 4) for 3 times.
6) Check DTC. 6
Wire harness check
1) Measure voltage between “GRN” wire terminal of electric
throttle body connector and engine ground with ignition
switch turned ON.
Is voltage 4 – 6 V? Go to Step 9. Go to Step 7.
7 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at “C37- 54” and “C37-42” terminals.
3) If OK, measure resistance between “GRN” and “BLK” wire terminals of electric throttle body connector.
Is resistance infinity? Go to Step 8. “GRN” wire is shorted to
“BLK” wire.
8 Wire harness check
1) Measure resistance between “GRN” wire terminal of
electric throttle body connector and engine ground with
ignition switch turned OFF.
Is resistance infinity? Substitute a known-
good ECM and recheck.
“GRN” wire is shorted to
ground circuit.
9 Electric throttle body check
1) Check TP sensor referring to “Throttle Position Sensor
Performance Check” under “Electric Throttle Body
Assembly On-Vehicle Inspection in Section 1C”.
Is output voltage within specified value? Substitute a known-
good ECM and recheck.
Replace electric throttle
body.
Step Action Yes No
DTC detecting condition
Trouble area
Output voltage of TP sensor (main) is more than specified
value for specified time continuously.
(1 driving detection logic) • TP sensor (main) circuit
• Electric throttle body assembly
•ECM

Downloaded from www.Manualslib.com manuals search engine 1A-86 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 TP sensor and its circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ON ignition switch, check “TP Sensor 1 Volt” displayed on scan tool when accelerator pedal is idle
position and fully depressed.
Is displayed TP sensor value as described voltage in “Scan
To o l D a t a ” ? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
Go to Step 3.
3 ECM voltage check
1) Disconnect connector from electric throttle body with
ignition switch turned OFF.
2) Check for proper connection to electric throttle body at “RED”, “GRN” and “BLK” wire terminals.
3) If OK, measure voltage between “RED” wire terminal of electric throttle body connector and engine ground with
ignition switch turned ON.
Is voltage 4 – 6 V? Go to Step 5.
Go to Step 4.
4 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at “C37- 43” terminal.
3) Measured voltage between “C37-43” 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.
5 Wire harness check
1) Measure voltage between “GRN” wire terminal of electric
throttle body connector and engine ground with ignition
switch turned ON.
Is voltage 4 – 6 V? Go to Step 9.
Go to Step 6.
"GRN"
"RED"
"WHT"
"BLK"
"LT GRN/BLK"
"LT GRN/RED"
I4RS0B110022-02

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6Wire harness check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Check for proper connection of ECM connector at “C37- 43” and “C37-54” terminals.
4) If OK, measure voltage between “C37-54” terminal of ECM connector and engine ground with ignition switch
turned ON.
Is voltage 4 -6 V? “GRN” wire is open or
high resistance circuit.
Go to Step 7.
7 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “GRN” and “RED” wire terminals of electric th rottle body connector.
Is resistance infinity? Go to Step 8. “GRN” wire is shorted to
“RED” wire.
8 Wire harness check
1) Turn ON ignition switch.
2) Measure voltage between “C37-54” terminal of ECM
connector and engine ground.
Is voltage 0 V? Substitute a known-
good ECM and recheck.
“GRN” wire is shorted to
power circuit.
9 Ground circuit check
1) Turn OFF ignition switch.
2) Measure resistance between “BLK” wire terminal of
electric throttle body connector and engine ground.
Is resistance below 5
Ω? Go to Step 11. Go to Step 10.
10 Ground circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Check for proper connection of ECM connector at “C37- 42” terminal.
3) Measure resistance between “C37-42” terminal of ECM connector and engine ground with ignition switch turned
OFF.
Is resistance below 5
Ω? “BLK” wire is open or
high resistance circuit.
Faulty ECM ground
circuit. If circuit is OK,
substitute a known-
good ECM and recheck.
11 Electric throttle body check
1) Check TP sensor referring to “Throttle Position Sensor
Performance Check” under “Electric Throttle Body
Assembly On-Vehicle Inspection in Section 1C”.
Is output voltage within specified value? Substitute a known-
good ECM and recheck.
Replace electric throttle
body.
Step Action Yes No

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NOTE
When DTC P0123 and P0223 are indicated together, it is possible that “RED” wire shorted to power
circuit and/or “BLK” wire open.

DTC Confirmation Procedure
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Keep the accelerator pedal at idle position for 2 seconds.
4) Keep the accelerator pedal at fully depressed position for 2 seconds.
5) Repeat Step 3) and 4) for 3 times.
6) 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 TP sensor and its circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ON ignition switch, check “TP Sensor 2 Volt” displayed on scan tool when accelerator pedal is idle
position and fully depressed.
Is displayed TP sensor value as described voltage in “Scan
To o l D a t a ” ? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
Go to Step 3.
3 ECM voltage check
1) Disconnect connector from electric throttle body with
ignition switch turned OFF.
2) Check for proper connection to electric throttle body at “RED”, “WHT” and “BLK” wire terminals.
3) If OK, measure voltage between “RED” wire terminal of electric throttle body connector and engine ground with
ignition switch turned ON.
Is voltage 4 – 6 V? Go to Step 6.
Go to Step 4.
"GRN"
"RED"
"WHT"
"BLK"
"LT GRN/BLK"
"LT GRN/RED"
I4RS0B110022-02

Downloaded from www.Manualslib.com manuals search engine 1A-104 Engine General Information and Diagnosis:
4Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection of ECM connector at “C37- 43” terminal.
3) Measure voltage between “C37-43” 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.
5 Wire harness check
1) Measure voltage between “WHT” wire terminal of
electric throttle body connector and engine ground with
ignition switch turned ON.
Is voltage 4 – 6 V? Go to Step 9.
Go to Step 6.
6 Wire harness check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Check for proper connection of ECM connector at “C37- 43” and “C37-40” terminals.
4) If OK, measure voltage between “C37-40” terminal of ECM connector and engine ground with ignition switch
turned ON.
Is voltage 4 – 6 V? “WHT” wire is open or
high resistance circuit.
Go to Step 7.
7 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “WHT” and “RED” wire terminals of electric thrott le body assembly connector.
Is resistance infinity? Go to Step 8.
“WHT” wire is shorted to
“RED” wire.
8 Wire harness check
1) Turn ON ignition switch.
2) Measure voltage between “C37-40” terminal of ECM
connector and engine ground.
Is voltage 0 V? Substitute a known-
good ECM and recheck.
“WHT” wire is shorted to
power circuit.
9 Ground circuit check
1) Turn OFF ignition switch.
2) Measure resistance between “BLK” wire terminal of
electric throttle body connector and engine ground.
Is resistance below 5
Ω? Go to Step 11. Go to Step 10.
10 Ground circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Check for proper connection of ECM connector at “C37- 42” terminal.
3) Measure resistance between “C37-42” terminal of ECM connector and engine ground with ignition switch turned
OFF.
Is resistance below 5
Ω? “BLK” wire is open or
high resistance circuit.
Faulty ECM ground
circuit. If circuit is OK,
substitute a known-
good ECM and recheck.
Step Action Yes No

Downloaded from www.Manualslib.com manuals search engine 1A-110 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 CKP sensor and connector for proper installation check
Is CKP sensor installed properly and connector connected
securely? Go to Step 3.
Correct.
3 Wire harness and connection check
1) Disconnect connector from CKP sensor with ignition
switch turned OFF.
2) Check for proper connection to CKP sensor at “BLK/ RED”, “PNK” and “BLK/ORN” wire terminals.
3) If OK, turn ON ignition switch and check voltage at “BLK/ RED”, “PNK” and “BLK/ORN” wire terminals of
disconnected CKP sensor connector.
CKP sensor voltage
Terminal “B+”: 10 – 14 V
Terminal “Vout”: 4 – 5 V
Terminal “GND”: 0 V
Is check result satisfactory? Go to Step 7. Go to Step 4.
4 Was terminal “Vout” voltage in Step 3 within specification? Go to Step 5. “PNK” wire is open or
shorted to ground /
power supply circuit.
If wire and connection
are OK, substitute a
known-good ECM and
recheck.
5 Ground circuit check
1) Turn ignition switch to OFF position.
2) Measure resistance between “BLK/ORN” wire terminal
of CKP sensor connector and engine ground.
Is measured resistance value less than 3
Ω? Go to Step 6. “BLK/ORN” wire is open
or high resistance.
I2RH0B110048-01

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3Wire harness and connection check
1) Disconnect connector from CMP sensor.
2) Check for proper connection to CMP sensor at “BLK/
RED”, “RED/YEL” and “B LK/ORN” wire terminals.
3) If OK, turn ON ignition switch and check voltage at “BLK/ RED”, “RED/YEL” and “BLK/ORN” wire terminals of
disconnected CMP sensor connector.
CMP sensor voltage
Terminal “B+”: 10 – 14 V
Terminal “Vout”: 4 – 5 V
Terminal “GND”: 0 V
Is check result satisfactory? Go to Step 7. Go to Step 4.
4 Was terminal “Vout” voltage in Step 3 within specification? Go to Step 5. “RED/YEL” wire is open
or shorted to ground /
power supply circuit.
If wire and connection
are OK, substitute a
known-good ECM and
recheck.
5 Ground circuit check
1) Turn ignition switch to OFF position.
2) Measure resistance between “BLK/ORN” wire terminal
of CMP sensor connector and engine ground.
Is measured resistance value less than 3
Ω? Go to Step 6. “BLK/ORN” wire is open
or high resistance
circuit.
6 Was terminal “B+” voltage in Step 3 within specification? Go to Step 7. “BLK/RED” wire is open
circuit. If wire and
connection are OK,
substitute a known-
good ECM and recheck.
7 CMP sensor check
1) Check CMP sensor and signal rotor tooth referring to
“Camshaft Position (CMP) Sensor Inspection in Section
1C”.
Is check result satisfactory? Substitute a known-
good ECM and recheck.
Replace CMP sensor
and/or intake camshaft.
Step Action Yes No
I4RS0B110094-01

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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.

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 Ignition spark check
1) Check that each spark plug sparks referring to “Ignition
Spark Test in Section 1H”.
Is check result satisfactory? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.Go to Step 3.
3 Ignition coil power, output and ground circuit check
1) Disconnect ignition coil connector of the cylinder found
as faulty in Step 2.
2) Check ignition coil circuit of the cylinder found as faulty in Step 2 for the following.
• Voltage between power circuit wire terminal of ignition coil connector and vehicle body ground is 10 – 14 V
with ignition switch turned ON.
• Voltage between output circuit wire terminal of ignition coil connector and vehicle body ground is 4 – 6 V with
ignition switch turned ON.
• Resistance between ground circuit wire terminal of ignition coil connector and vehicle body ground is less
than 2 Ω.
Are they in good condition? Go to Step 4.
Repair or replace
defective wire.
4 Ignition coil check
1) Replace ignition coil for No.1 and No.4 spark plugs with
ignition coil for No.2 and No.3 spark plugs.
Is the cylinder found as faulty in good condition now? Faulty ignition coil. Go to Step 5.
5 Ignition coil output circuit check
1) Disconnect connectors from ECM.
2) Check ignition coil circuit of the cylinder found as faulty
in Step 2 for the following.
• Resistance of output wire circuit between ignition coil
connector and ECM connector is less than 2 Ω.
• Resistance of output wire circuit between ignition coil connector and vehicle b ody ground is infinity.
Are they in good condition? Substitute a known-
good ECM and recheck.
Repair or replace
defective wire.