Acc pedal to ecm SUZUKI SWIFT 2005 2.G Service User Guide

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-83
DTC P0122: Throttle / Pedal Position Sensor / Switch “A” (Main) Circuit LowS7RS0B1104029
Wiring Diagram
DTC Detecting Condition and Trouble Area
NOTE
When DTC P0122 and P0222 are indicated together, it is possible that “RED” wire open circuit.

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.
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
12V
5VBLK/REDBLK/RED
BLK/YEL
12BLK/YEL
BLK/YEL
BRN/WHT
E23-1
E23-60
C37-58
C37-15 C37-30
BLK/ORN
BLKBLKE23-31 BLK
BLK/RED
BLU/ORN
RED/YELYEL/BLU
LT GRN/RED
LT GRN/BLK
RED
GRN
WHT
BLK
E23-16
E23-45
E23-32
C37-45
C37-44
C37-41C37-42
C37-40
C37-54
C37-43
1-1
1-2
1-3 3
4
5
8 67
10
9
E23-29 GRNBLK/WHTWHT
BLK/RED
I6RS0C110015-01
1. Electric throttle body assembly
3. ECM 8. “IG ACC” fuse
1-1. Throttle actuator 4. Main relay 9. “IG COIL” fuse
1-2. TP sensor (main) 5. Individual circuit fuse box No.110. Ignition switch
1-3. TP sensor (sub) 6. “TH MOT” fuse
2. Throttle actuator control relay 7. “FI” fuse
DTC detecting condition Trouble area
Output voltage of TP sensor (main) is less 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-84 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
Tool Data:”? 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 6.
Go to Step 4.
4 ECM voltage 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” terminal.
4) If OK, measure voltage between “C37-43” terminal of ECM connector and engine ground with ignition switch
turned ON.
Is voltage 4 – 6 V? “RED” wire is open or
high resistance circuit.
Go to Step 5.
5 Wire harness check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “C37-43” terminal of ECM connector and engine ground.
Is resistance infinity? Substitute a known-
good ECM and check.
“RED” wire is shorted to
ground circuit.
"GRN"
"RED"
"WHT"
"BLK"
"LT GRN/BLK"
"LT GRN/RED"
I4RS0B110022-02

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-85
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

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-89
DTC Confirmation Procedure
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.

NOTE
Check to make sure that following conditions ar e satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10 °C (14 ° F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine coolant temperature: 70 °C (158 °F) to 150 °C (302 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Drive vehicle at 40 mph (60 km/h) or higher. (engine speed: 2500 – 3000 r/min.)
5) Keep above vehicle speed for 6 min. or more. (Throt tle valve opening is kept constant in this step.)
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting (with fuel cut for 3 sec. or more)
and then stop vehicle.
7) Check DTC and pending 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 there DTC(s) other than HO2S-1? Go to applicable DTC
diag. flow.Go to Step 3.
3 HO2S-1 signal check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Warm up engine to normal operating temperature and keep it at 2000 r/min. for 60 sec.
3) Repeat racing engine (Repeat depressing accelerator pedal 5 to 6 times continuous ly to enrich A/F mixture and
take foot off from pedal to enlean it).
Does HO2S-1 output voltage deflect between below 0.3 V
and over 0.6 V repeatedly? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”. If check result is
OK, go to Step 9.
Go to Step 4.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-91
DTC P0133: O2 Sensor (HO2S) Circuit Slow Response (Sensor-1)S7RS0B1104032
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
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.

NOTE
Check to make sure that following conditions ar e satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10 °C (14 ° F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine coolant temperature: 70 °C (158 °F) to 150 °C (302 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Drive vehicle at 40 mph (60 km/h) or higher. (engine speed: 2500 – 3000 r/min.)
5) Keep above vehicle speed for 6 min. or more. (Throt tle valve opening is kept constant in this step.)
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting (with fuel cut for 3 sec. or more)
and then stop vehicle.
7) Check if DTC and pending DTC exist by using scan tool. If not, check if oxygen sensor monitoring test has been
completed by using scan tool. If not in both of above c hecks (i.e., no DTC and pending DTC and oxygen sensor
monitoring test not completed), check vehicle cond ition (environmental) and repeat Step 3) through 6).
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
Response time (time to change from lean to rich or from rich to lean) of HO2S-1 output
voltage is about 1 sec. at minimum or aver age time of 1 cycle is 5 sec. at minimum.
(*2 driving cycle detection logic, monitoring once per driving cycle) Heated oxygen sensor-1
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 there DTC(s) other than HO2S-1 (DTC P0133)? Go to applicable DTC
diag. flow.Replace HO2S-1.

Downloaded from www.Manualslib.com manuals search engine 1A-92 Engine General Information and Diagnosis:
DTC P0134: O2 Sensor (HO2S) Circuit No Activity Detected (Sensor-1)S7RS0B1104033
Wiring Diagram
Refer to “DTC P0131 / P0132: O2 Sensor (HO2S) Circuit Low Voltage / High Voltage (Sensor-1)”
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
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.

NOTE
Check to make sure that following conditions ar e satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10 °C (14 ° F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine Coolant temperature: 70 °C (158 °F) to 150 °C (302 ° F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Drive vehicle at 40 mph (60 km/h) or higher. (engine speed: 2500 – 3000 r/min.)
5) Keep above vehicle speed for 6 min. or more. (Throt tle valve opening is kept constant in this step.)
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting (with fuel cut for 3 sec. or more)
and then stop vehicle.
7) Check if DTC and pending DTC exist by using scan tool. If not, check if oxygen sensor monitoring test has been
completed by using scan tool. If not in both of above c hecks (i.e., no DTC and pending DTC and oxygen sensor
monitoring test not completed), check vehicle cond ition (environmental) and repeat Step 3) through 6).
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
HO2S voltage is higher than 0.6 V for more than 1 min
continuously after warming up engine or HO2S voltage is lower
than 0.3 V for more than 1 min continuously after warming up
engine.
(2 driving cycle detection logic) •HO2S-1
• HO2S-1 circuit
• Exhaust gas leakage
•ECM
• Air intake system
Step
Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-93
2HO2S-1 output voltage check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Warm up engine to normal operating temperature and keep it at 2000 r/min. for 60 sec.
3) Repeat racing engine (Repeat depressing accelerator pedal 5 to 6 times continuous ly to enrich A/F mixture and
take foot off from pedal to enlean it) and check HO2S
output voltages displayed on scan tool.
Is over 0.6 V and below 0.3 V indicated? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”. If check result is
OK, go to Step 3.
Go to Step 3.
3 HO2S-1 ground check
1) Disconnect connector from HO 2S-1 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-1 at “BLK/RED”, “WHT”, “BLK/WHT” and “YEL” wire terminals.
3) If wire and connection are OK, measure resistance between “YEL” wire terminal of HO2S-1 connector and
engine ground.
Is resistance less than 5
Ω? Go to Step 4. “YEL” wire is open or
high resistance circuit.
Poor “C37-57” terminal
connection. Faulty ECM
ground.
If they are OK,
substitute a known-
good ECM and recheck.
4 Wire circuit check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Measure resistance between “WHT” wire terminal of HO2S-1 connector and “C37-10” terminal of ECM
connector.
Is resistance less than 5
Ω? Go to Step 5. “WHT” wire is high
resistance circuit or
open circuit. Poor “C37-
10” terminal connection
of ECM connector.
Faulty ECM ground. If
they are OK, substitute
a known-good ECM and
recheck.
5 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “WHT” wire terminal of HO2S-1 connector and vehicle body ground.
Is resistance infinity? Go to Step 6. “WHT” wire is shorted to
ground circuit.
6 HO2S-1 heater circuit check
1) Check HO2S-1 heater circuit referring to “DTC P0031 /
P0032: HO2S Heater Control Circuit Low / High
(Sensor-1)”.
Is it in good condition? Go to Step 7. Repair HO2S-1 circuit.
7 Exhaust system check
1) Check exhaust system for exhaust gas leakage.
Is it OK? Go to Step 4 in “DTC
P0171 / P0172: Fuel
System Too Lean /
Rich”.
If it is in good condition,
go to Step 8.Repair leakage of
exhaust system.
8 Air intake system check
1) Check air intake system for clog or leak.
Is it OK? Check HO2S-1 referring
to “HO2S-1 and HO2S-
2 Heater On-Vehicle
Inspection in Section
1C”.
If it is in good condition,
substitute a known-
good ECM and recheck.Repair or replace air
intake system.
Step Action Yes No

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-95
DTC Confirmation Procedure
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.

NOTE
Check to make sure that following conditions ar e satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10 °C (14 ° F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine Coolant temperature: 70 °C (158 °F) to 150 °C (302 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Increase vehicle speed to 70 – 80 km/h (43 – 50 mile/h) at 5th gear or D range.
5) Release accelerator pedal and with engine brake applied, ke ep vehicle coasting (with fuel cut for 4 sec. or more),
then stop vehicle and run engine at idle speed for 60 sec. or more.
6) Repeat Step 4).
7) Keep above vehicle speed for 8 min. or more. (Throt tle valve opening is kept constant in this step.)
8) Repeat Step 5).
9) Check DTC and pending 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 there DTC(s) other than fuel system (DTC P0171 / P0172)
and HO2S-2 (DTC P0140)? Go to applicable DTC
diag. flow.Go to Step 3.
3 HO2S-2 and its circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Warm up engine to normal operating temperature and keep it at 2000 r/min. for 60 sec.
3) Repeat racing engine (Repeat depressing accelerator pedal 5 to 6 times continuous ly to enrich A/F mixture and
take foot off from pedal to enlean it).
Does HO2S-2 output voltage indicate deflection between
over 0.35 V and below 0.25 V? Go to “DTC P0171 /
P0172: Fuel System
Too Lean / Rich”.
Go to Step 4.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-97
DTC P0140: O2 Sensor (HO2S) Circuit No Activity Detected (Sensor-2)S7RS0B1104035
Wiring Diagram
Refer to “DTC P0137 / P0138: O2 Sensor (HO2S) Circuit Low Voltage / High Voltage (Sensor-2)”
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
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) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Increase vehicle speed to 60 – 80 km/h (37 – 50 mile/h) at 5th gear or D range.
5) Release accelerator pedal and with engine brake applied, ke ep vehicle coasting (with fuel cut for 4 sec. or more),
then stop vehicle and run engine at idle speed for 60 sec. or more.
6) Check DTC and pending 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
HO2S-2 voltage is higher than specified value after warming up engine
(circuit open).
(2 driving cycle detection logic) •HO2S-2
• HO2S-2 circuit
•ECM
• Exhaust gas leakage
• Air intake system
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 HO2S-2 ground check
1) Disconnect connector from HO 2S-2 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-2 connector at “RED/BLU”, “BRN”, “YEL” and “BLK/WHT” wire
terminals.
3) If connections are OK, m easure resistance between
“YEL” wire terminal of HO2S-2 connector and engine
ground.
Is resistance less than 5
Ω? Go to Step 3. “YEL” wire is open or
high resistance circuit.
Poor “C37-57” terminal
connection. Faulty ECM
ground.
If they are OK,
substitute a known-
good ECM and recheck.