2005 INFINITI FX35 vq35de

DTC P1128 THROTTLE CONTROL MOTOR EC-437
[VQ35DE]
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Revision: 2005 July 2005 FX
DTC P1128 THROTTLE CONTROL MOTORPFP:16119
Component DescriptionABS006TR
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis LogicABS006TS
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureABS006TT
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 2 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If DTC is detected, go to EC-439, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1128
11 2 8 Throttle control motor
circuit short ECM detects short in both circuits between
ECM and throttle control motor.

Harness or connectors
(Throttle control motor circuit is shorted.)

Electric throttle control actuator
(Throttle control motor)
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.
SEF058Y

EC-438
[VQ35DE]
DTC P1128 THROTTLE CONTROL MOTOR
Revision: 2005 July 2005 FX
Wiring DiagramABS006TU
TBWM0401E

DTC P1128 THROTTLE CONTROL MOTOR EC-439
[VQ35DE]
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Revision: 2005 July 2005 FX
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureABS006TV
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-170, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
4L/W Throttle control motor
(Close) [Ignition switch: ON]

Engine stopped

Selector lever: D

Accelerator pedal: Fully released 0 - 14V
5L/B Throttle control motor
(Open) [Ignition switch: ON]

Engine stopped

Selector lever: D

Accelerator pedal: Fully depressed 0 - 14V
PBIB1104E
PBIB1105E
PBIB2625E

EC-440
[VQ35DE]
DTC P1128 THROTTLE CONTROL MOTOR
Revision: 2005 July 2005 FX
2. CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Disconnect electric throttle control actuator harness connector.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following terminals. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK THROTTLE CONTROL MOTOR
Refer to EC-440, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> GO TO 5.
4. CHECK INTERMITTENT INCIDENT
Refer to EC-163, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness or connectors.
5. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-96, "
Throttle Valve Closed Position Learning" .
3. Perform EC-97, "
Idle Air Volume Learning" .
>> INSPECTION END
Component InspectionABS006TW
THROTTLE CONTROL MOTOR
1. Disconnect electric throttle control actuator harness connector.
2. Check resistance between terminals 3 and 6.
3. If NG, replace electric throttle control actuator and go to next step.
4. Perform EC-96, "
Throttle Valve Closed Position Learning" .
5. Perform EC-97, "
Idle Air Volume Learning" .
Electric throttle control
actuator terminal ECM terminal Continuity
3 5 Should not exist
4 Should exist
6 5 Should exist
4 Should not exist
PBIB1557E
Resistance: Approximately 1 - 15 Ω [at 25 °C (77 °F)]
PBIB0095E

DTC P1128 THROTTLE CONTROL MOTOR EC-441
[VQ35DE]
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Revision: 2005 July 2005 FX
Removal and InstallationABS006TX
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-19, "INTAKE MANIFOLD COLLECTOR" .

EC-442
[VQ35DE]
DTC P1146, P1166 HO2S2
Revision: 2005 July 2005 FX
DTC P1146, P1166 HO2S2PFP:226A0
Component DescriptionABS006UE
The heated oxygen sensor 2, after three way catalyst 1, monitors the
oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor ModeABS006UF
Specification data are reference values.
On Board Diagnosis LogicABS006UG
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-
gen storage capacity of the three way catalyst 1 causes the longer
switching time. To judge the malfunctions of heated oxygen sensor
2, ECM monitors whether the minimum voltage of sensor is suffi-
ciently low during the various driving condition such as fuel-cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)

Warm-up condition

After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load. Revving engine from idle to 3,000 rpm
quickly. 0 - 0.3V
←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2) LEAN
←→ RICH
PBIB2376E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1146
1146
(Bank 1) Heated oxygen sensor
2 minimum voltage
monitoring The minimum voltage from the sensor is not
reached to the specified voltage.

Harness or connectors
(The sensor circuit is open or shorted)

Heated oxygen sensor 2

Fuel pressure

Fuel injector
P1166
1166
(Bank 2)

DTC P1146, P1166 HO2S2 EC-443
[VQ35DE]
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Revision: 2005 July 2005 FX
DTC Confirmation ProcedureABS006UH
NOTE:
If DTC confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
TESTING CONDITION:
For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
2. Start engine and warm it up to the normal operating tempera- ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70 °C
(158 °F).
If not, warm up engine and go to next step when “COOLAN
TEMP/S” indication reaches to 70 °C (158 °F).
7. Open engine hood.
8. Select “HO2S2 (B1) P1146” or “HO2S2 (B2) P1166” of “HO2S2” in “DTC WORK SUPPORT” mode with CONSULT-II.
9. Start engine and following the instruction of CONSULT-II.
NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
10. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-448, "
Diagnostic Procedure" .
If “CAN NOT BE DIAGNOSED” is displayed, perform the following.
a. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
b. Return to step 1.
Overall Function CheckABS006UI
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 74 [HO2S2 (B1) signal] or 55 [HO2S2 (B2) signal] and ground.
SEF174Y
PBIB2372E

EC-444
[VQ35DE]
DTC P1146, P1166 HO2S2
Revision: 2005 July 2005 FX
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be below 0.18V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in D
position with “OD” OFF.
The voltage should be below 0.18V at least once during this
procedure.
8. If NG, go to EC-448, "
Diagnostic Procedure" .
PBIB1607E