service INFINITI FX35 2008 Service Manual

DTC P0117, P0118 ECT SENSOREC-195
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Wiring DiagramINFOID:0000000001326016
Diagnosis ProcedureINFOID:0000000001326017
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
TBWM0289E
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EC-196
< SERVICE INFORMATION >[VQ35DE]
DTC P0117, P0118 ECT SENSOR
2. Loosen and retighten ground screw on the body. Refer to
EC-144, "Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK ECT SENSOR POWER SUPPLY CIRCUIT
1. Disconnect engine coolant temperature (ECT) sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between ECT sensor terminal 1 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECT s ensor terminal 2 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-197, "
Component Inspection".
OK or NG
OK >> GO TO 5.
NG >> Replace engine coolant temperature sensor.
PBIB2625E
PBIB1563E
Voltage: Approximately 5V
PBIB0080E
Continuity should exist.
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DTC P0117, P0118 ECT SENSOREC-197
< SERVICE INFORMATION > [VQ35DE]
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5.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
Component InspectionINFOID:0000000001326018
ENGINE COOLANT TEMPERATURE SENSOR
Check resistance between engine cool ant temperature sensor termi-
nals 1 and 2 as shown in the figure.

If NG, replace engine coolant temperature sensor.
Removal and InstallationINFOID:0000000001326019
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-27.
PBIB2005E
Engine coolant temperature °C ( °F) Resistance k Ω
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P
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EC-198
< SERVICE INFORMATION >[VQ35DE]
DTC P0122, P0123 TP SENSOR
DTC P0122, P0123 TP SENSOR
Component DescriptionINFOID:0000000001326020
Electric throttle control actuator
consists of throttle control motor,
throttle position (TP) sensor, et c. The throttle position sensor
responds to the throttle valve movement.
The throttle position sensor has two sensors. These sensors are a
kind of potentiometers which transform the throttle valve position into
output voltage, and emit the voltage signal to the ECM. In addition,
these sensors detect the opening and closing speed of the throttle
valve and feed the voltage signals to the ECM. The ECM judges the
current opening angle of the throttle valve from these signals and the
ECM controls the throttle control motor to make the throttle valve
opening angle properly in response to driving condition.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326021
Specification data are reference values.
*: Throttle position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.
On Board Diagn osis LogicINFOID:0000000001326022
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001326023
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-200, "
Diagnosis Procedure".
PBIB0145E
MONITOR ITEM CONDITION SPECIFICATION
TP SEN 1-B1
TP SEN 2-B1*  Ignition switch: ON
(Engine stopped)
 Selector lever: D Accelerator pedal:
Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0122
0122 Throttle position sensor
2 circuit low input An excessively low voltage from the TP sensor
2 is sent to ECM.  Harness or connectors
(TP sensor 2 circuit is open or shorted.)
(APP sensor 2 circuit is shorted.)
 Electric throttle control actuator (TP sensor 2)
 Accelerator pedal position sensor (APP sensor 2)
P0123
0123
Throttle position sensor
2 circuit high input An excessively high voltage from the TP sensor
2 is sent to ECM.
Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
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DTC P0122, P0123 TP SENSOREC-199
< SERVICE INFORMATION > [VQ35DE]
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Wiring DiagramINFOID:0000000001326024
Specification data are reference values
and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals wh en measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
TBWM0393E
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EC-200
< SERVICE INFORMATION >[VQ35DE]
DTC P0122, P0123 TP SENSOR
Diagnosis Procedure
INFOID:0000000001326025
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-144, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK THROTTLE POSITION SE NSOR 2 POWER SUPPLY CIRCUIT-I
TER-
MI-
NAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
47 L Sensor power supply (Throt-
tle position sensor) [Ignition switch: ON]
Approximately 5V
50 W Throttle position sensor 1 [Ignition switch: ON]
 Engine stopped
 Selector lever: D
 Accelerator pedal: Fully released
More than 0.36V
[Ignition switch: ON]
 Engine stopped
 Selector lever: D
 Accelerator pedal: Fully depressed Less than 4.75V
66 B Sensor ground
(Throttle position sensor) [Engine is running]

Warm-up condition
 Idle speed Approximately 0V
69 R Throttle position sensor 2 [Ignition switch: ON]
 Engine stopped
 Selector lever: D
 Accelerator pedal: Fully released
Less than 4.75V
[Ignition switch: ON]
 Engine stopped
 Selector lever: D
 Accelerator pedal: Fully depressed More than 0.36V
91 G Sensor power supply
(APP sensor 2) [Ignition switch: ON]
Approximately 5V
PBIB2625E
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DTC P0122, P0123 TP SENSOREC-201
< SERVICE INFORMATION > [VQ35DE]
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1. Disconnect electric throttle c
ontrol actuator harness connector.
2. Turn ignition switch ON.
3. Check voltage between electric throttle control actuator terminal 1 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3.CHECK THROTTLE POSI TION SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric thrott le control actuator terminal 1 and ECM terminal 47.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit.
4.CHECK THROTTLE POSI TION SENSOR 2 POWER SUPPLY CIRCUIT-III
Check the following.
 Harness for short to power and short to ground, between the following terminals.
OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5.CHECK APP SENSOR
Refer to EC-517, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> GO TO 6.
6.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly.
2. Perform EC-85, "
Accelerator Pedal Released Position Learning".
3. Perform EC-85, "
Throttle Valve Closed Position Learning".
4. Perform EC-85, "
Idle Air Volume Learning".
PBIB1557E
Voltage: Approximately 5V
PBIB0082E
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 1 EC-199
91 APP sensor terminal 4EC-513
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EC-202
< SERVICE INFORMATION >[VQ35DE]
DTC P0122, P0123 TP SENSOR
>>
INSPECTION END
7.CHECK THROTTLE POSITION SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric thrott le control actuator terminal 5 and ECM terminal 66.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK THROTTLE POSITION SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 69 and electric throttle control actuator terminal 2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK THROTTLE POSITION SENSOR
Refer to EC-202, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-85, "
Throttle Valve Closed Position Learning".
3. Perform EC-85, "
Idle Air Volume Learning".
>> INSPECTION END
11 .CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
Component InspectionINFOID:0000000001326026
THROTTLE POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Perform EC-85, "
Throttle Valve Closed Position Learning".
3. Turn ignition switch ON.
4. Set selector lever to D position. Continuity should exist.
Continuity should exist.
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DTC P0122, P0123 TP SENSOREC-203
< SERVICE INFORMATION > [VQ35DE]
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5. Check voltage between ECM terminals 50 (TP sensor 1signal),
69 (TP sensor 2signal) and body ground under the following
conditions.
6. If NG, replace electric throttle control actuator and go to the next
step.
7. Perform EC-85, "
Throttle Valve Closed Position Learning".
8. Perform EC-85, "
Idle Air Volume Learning".
Removal and InstallationINFOID:0000000001326027
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-19.
Terminal Accelerator pedal Voltage
50
(Throttle position sensor 1) Fully released More than 0.36V
Fully depressed Less than 4.75V
69
(Throttle position sensor 2) Fully released Less than 4.75V
Fully depressed More than 0.36V
PBIB1608E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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EC-204
< SERVICE INFORMATION >[VQ35DE]
DTC P0125 ECT SENSOR
DTC P0125 ECT SENSOR
Component DescriptionINFOID:0000000001326028
NOTE:
If DTC P0125 is displayed with P0117 or P0118, fi
rst perform the trouble diagnosis for DTC P0117 or
P0118. Refer to EC-193
.
The engine coolant temperature (ECT) sensor is used to detect the
engine coolant temperature. The sensor modifies a voltage signal
from the ECM. The modified signal returns to the ECM as the engine
coolant temperature input. The sens or uses a thermistor which is
sensitive to the change in temperat ure. The electrical resistance of
the thermistor decreases as temperature increases.

*: This data is reference values and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring in put/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000001326029
DTC Confirmation ProcedureINFOID:0000000001326030
CAUTION:
Be careful not to overheat engine.
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check that “COOLAN TEMP/S” is above 10 °C (50 °F).
If it is above 10 °C (50 °F), the test result will be OK.
If it is below 10 °C (50 °F), go to following step.
4. Start engine and run it for 65 minutes at idle speed.
SEF594K
Engine coolant
temperature °C ( °F) Voltage* V Resistance k
Ω
-10 (14) 4.4 7.0 - 11.4s 20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0125
0125 Insufficient engine cool-
ant temperature for
closed loop fuel control  Voltage sent to ECM from the sensor is not
practical, even when some time has passed
after starting the engine.
 Engine coolant temperature is insufficient for closed loop fuel control.  Harness or connectors
(High resistance in the circuit)
 Engine coolant temperature sensor
Thermostat
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