sensor INFINITI FX35 2008 Service Manual

EC-424
< SERVICE INFORMATION >[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
DTC P0643 SENSOR POWER SUPPLY
On Board Diagn
osis LogicINFOID:0000000001326271
This self-diagnosis has 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:0000000001326272
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-426, "
Diagnosis Procedure".
DTC No.Trouble diagnosis
name DTC detecting condition Possible cause
P0643
0643 Sensor power supply
circuit short ECM detects a voltage of power source for
sensor is excessively low or high.  Harness or connectors
(APP sensor 1 circuit is shorted.)
(PSP sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is short-
ed.)
(EVAP control system pressure sensor circuit
is shorted.)
 Accelerator pedal position sensor (APP sensor 1)
 EVAP control system pressure sensor
 Power steering pressure sensor
 Refrigerant pressure sensor
Engine operation 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.
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DTC P0643 SENSOR POWER SUPPLYEC-425
< SERVICE INFORMATION > [VQ35DE]
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Wiring DiagramINFOID:0000000001326273
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.
TBWM1400E
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EC-426
< SERVICE INFORMATION >[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
Diagnosis Procedure
INFOID:0000000001326274
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 ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT-I
TER-
MI-
NAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
48 LG Sensor power supply
(EVAP control system pres-
sure sensor)
[Ignition switch: ON]
Approximately 5V
49 PU Sensor power supply
(Refrigerant pressure sen-
sor) [Ignition switch: ON]
Approximately 5V
68 BR Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
82 B/W Sensor ground
(APP sensor 1, ASCD steer-
ing switch, ICC steering
switch) [Engine is running]

Warm-up condition
 Idle speed Approximately 0V
83 G/OR Sensor ground
(APP sensor 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 0V
90 L/B Sensor power supply
(APP sensor 1)
[Ignition switch: ON]
Approximately 5V
91 G Sensor power supply
(APP sensor 2) [Ignition switch: ON]
Approximately 5V
98 Y/R Accelerator pedal position
sensor 2 [Ignition switch: ON]
 Engine stopped
 Accelerator pedal: Fully released
0.15 - 0.60V
[Ignition switch: ON]
 Engine stopped
 Accelerator pedal: Fully depressed 1.95 - 2.40V
106 OR Accelerator pedal position
sensor 1 [Ignition switch: ON]
 Engine stopped
 Accelerator pedal: Fully released
0.5 - 1.0V
[Ignition switch: ON]
 Engine stopped
 Accelerator pedal: Fully depressed 3.9 - 4.7V
PBIB2625E
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DTC P0643 SENSOR POWER SUPPLYEC-427
< SERVICE INFORMATION > [VQ35DE]
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1. Disconnect accelerator pedal position (APP) sensor harness
connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 6 and ground with
CONSULT-III or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
3.CHECK SENSOR POWER SUPPLY CIRCUITS
Check harness for short to power and short to ground, between the following terminals.
OK or NG
OK >> GO TO 6.
NG >> Repair short to ground or short to power in harness or connectors.
4.CHECK COMPONENTS
Check the following.
 Refrigerant pressure sensor (Refer to ATC-69, "
Magnet Clutch Circuit".)
 Power steering pressure sensor (Refer to EC-416, "
Component Inspection".)
 EVAP control system pressure sensor (Refer to EC-373, "
Component Inspection".)
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning component.
5.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-511, "
Component Inspection".
OK or NG
OK >> GO TO 7.
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".
PBIB1580E
Voltage: Approximately 5V
PBIB0914E
ECM terminal Sensor terminal Reference Wiring Diagram
90 APP sensor terminal 6 EC-508
49 Refrigerant pressure sensor terminal 1EC-582
68 PSP sensor terminal 1EC-414
48 EVAP control system pressure sensor terminal 3EC-377
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EC-428
< SERVICE INFORMATION >[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
>>
INSPECTION END
7.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
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EC-434
< SERVICE INFORMATION >[VQ35DE]
DTC P1148, P1168 CLO
SED LOOP CONTROL
DTC P1148, P1168 CLOSED LOOP CONTROL
On Board Diagnosis LogicINFOID:0000000001326282
These self-diagnoses have the one trip detection logic.
NOTE:
DTC P1148 or P1168 is displayed with another DTC for air fuel ratio (A/F) sensor 1.
Perform the trouble diagnosis for the corresponding DTC.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1148
11 4 8
(Bank 1) Closed loop control
function The closed loop control function for bank 1 does
not operate even when vehicle is driving in the
specified condition.
 Harness or connectors
[Air fuel ratio (A/F) sensor 1 circuit is open
or shorted.]
 Air fuel ratio (A/F) sensor 1
 Air fuel ratio (A/F) sensor 1 heater
P1168
11 6 8
(Bank 2) The closed loop control function for bank 2 does
not operate even when vehicle is driving in the
specified condition.
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DTC P1217 ENGINE OVER TEMPERATUREEC-437
< SERVICE INFORMATION > [VQ35DE]
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DTC P1217 ENGINE OVER TEMPERATURE
DescriptionINFOID:0000000001326291
SYSTEM DESCRIPTION
NOTE:

If DTC P1217 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-146
.
 If DTC P1217 is displayed with DTC U1010, first performed the trouble diagnosis for DTC U1010.
Refer to EC-148
.
Cooling Fan Control
*1: The ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to ECM through CAN communication line.
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant
pressure, and air conditioner ON signal. The control system has 4-step control [HIGH/MIDDLE/LOW/OFF].
Cooling Fan Operation
Cooling Fan Relay Operation
The ECM controls cooling fan relays in the IPDM E/R through CAN communication line.
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
Cooling fan
controlIPDM E/R
(Cooling fan relay)
Battery
Battery voltage*
1
Wheel sensor
Vehicle speed*2
Engine coolant temperature sensor Engine coolant temperature
Air conditioner switchAir conditioner ON signal*
2
Refrigerant pressure sensor Refrigerant pressure
PBIB3369E
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EC-442
< SERVICE INFORMATION >[VQ35DE]
DTC P1217 ENGINE
OVER TEMPERATURE
No >> GO TO 3.
2.CHECK COOLING FAN OPERATION
With CONSULT-III
1. Start engine and let it idle.
2. Select “COOLING FAN” in “ACTIVE TEST” mode with CONSULT-III.
3. Make sure that cooling fans-1 and -2 operate at each speed (LOW/MID/HI).
OK or NG
OK >> GO TO 4.
NG >> Check cooling fan control circuit. (Go to “PROCEDURE B”.)
3.CHECK COOLING FAN OPERATION
Without CONSULT-III
1. Perform IPDM E/R auto active test and check cooling fan motors operation, refer to PG-20, "
Auto Active
Te s t".
2. Make sure that cooling fans-1 and -2 operate at each speed (Low/Middle/High).
OK or NG
OK >> GO TO 4.
NG >> Check cooling fan control circuit. (Go to “PROCEDURE B”.)
4.CHECK COOLING SYSTEM FOR LEAK
Refer to CO-10, "
Inspection".
OK or NG
OK >> GO TO 5.
NG >> Check the following for leak. Hose
 Radiator
 Water pump
5.CHECK RADIATOR CAP
Refer to CO-14, "
Checking Radiator Cap".
OK or NG
OK >> GO TO 6.
NG >> Replace radiator cap.
6.CHECK THERMOSTAT
Refer to CO-27
.
OK or NG
OK >> GO TO 7.
NG >> Replace thermostat
7.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-197, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace engine coolant temperature sensor.
8.CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to EC-445, "
Main 12 Causes of Overheating".
>> INSPECTION END
PROCEDURE B
1.CHECK COOLILNG FAN POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connectors E6.
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DTC P1225 TP SENSOREC-447
< SERVICE INFORMATION > [VQ35DE]
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DTC P1225 TP SENSOR
Component DescriptionINFOID:0000000001326299
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.
On Board Diagnosis LogicINFOID:0000000001326300
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureINFOID:0000000001326301
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 10V at idle.
1. Turn ignition switch ON.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-447, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001326302
1.CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
3. Check if foreign matter is c aught between the throttle valve and
the housing.
OK or NG
OK >> GO TO 2.
NG >> Remove the foreign matter and clean the electric throttle control actuator inside.
2.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".
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1225
1225 Closed throttle position
learning performance Closed throttle position learning value is exces-
sively low.  Electric throttle control actuator
(TP sensor 1 and 2)
PBIB1556E
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EC-448
< SERVICE INFORMATION >[VQ35DE]
DTC P1225 TP SENSOR
>>
INSPECTION END
Removal and InstallationINFOID:0000000001326303
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-19.
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