2008 INFINITI FX35 engine control system

DTC P0011, P0021 IVT CONTROL
EC-727
< SERVICE INFORMATION > [VK45DE]
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DTC P0011, P0021 IVT CONTROL
DescriptionINFOID:0000000001326554
SYSTEM DESCRIPTION
*: This signal is sent to the ECM through CAN communication line
This mechanism hydraulically controls cam phases c
ontinuously with the fixed operating angle of the intake
valve.
The ECM receives signals such as crankshaft posit ion, camshaft position, engine speed, and engine coolant
temperature. Then, the ECM sends ON/OFF pulse duty si gnals to the intake valve timing (IVT) control sole-
noid valve depending on driving status. This makes it po ssible to control the shut/open timing of the intake
valve to increase engine torque in low/mid speed range and output in high-speed range.
COMPONENT DESCRIPTION
Intake Valve Timing Control Solenoid Valve
Intake Valve Timing (IVT) control solenoid valve is activated by ON/
OFF pulse duty (ratio) signals from the ECM.
The IVT control solenoid valve changes the oil amount and direction
of flow through intake valve timing control unit or stops oil flow.
The longer pulse width advances valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve
stops oil pressure flow to fix the intake valve angle at the control
position.
Intake Valve Timing Control Position Sensor
Sensor Input signal to ECM function ECM Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed
Intake valve
timing controlIntake valve timing control
solenoid valve
Intake valve timing control position sensor Intake valve timing signal
Engine coolant temperature sensor Engine coolant temperature
Wheel sensor Vehicle speed*
PBIB3276E
PBIB1842E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-739
< SERVICE INFORMATION > [VK45DE]
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DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
DescriptionINFOID:0000000001326562
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F
sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F sensor 1 element at the specified range.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326563
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001326564
DTC Confirmation ProcedureINFOID:0000000001326565
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, confi rm that battery voltage is between 10.5V and 16V at
idle.
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-743, "
Diagnosis Procedure".
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Air fuel ratio (A/F) sensor 1
heater controlAir fuel ratio (A/F) sensor 1
heater
Mass air flow sensor Amount of intake air
MONITOR ITEM CONDITION SPECIFICATION
A/F S1 HTR (B1)
A/F S1 HTR (B2)  Engine: After warming up, idle the engine 0 - 100%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0031
0031
(Bank 1) Air fuel ratio (A/F) sensor
1 heater control circuit low The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
 A/F sensor 1 heater
P0051
0051
(Bank 2)
P0032
0032
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit
high The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
 A/F sensor 1 heater
P0052
0052
(Bank 2)
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-746
< SERVICE INFORMATION >[VK45DE]
DTC P0037, P
0038, P0057, P0058 HO2S2 HEATER
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
DescriptionINFOID:0000000001326570
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxy gen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326571
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001326572
DTC Confirmation ProcedureINFOID:0000000001326573
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:
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600 OFF
Below 3,600 rpm after the following conditions are met.
 Engine: After warming up
 Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and at idle for 1 minute under no load ON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)  Engine speed: Below 3,600 rpm after the following conditions are met.
- Engine: After warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and at
idle for 1 minute under no load ON
 Engine speed: Above 3,600 rpm OFF
DTC No. Trouble diagnosis
name DTC detecting condition Possible cause
P0037
0037
(Bank 1) Heated oxygen
sensor 2 heater
control circuit low The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater circuit is
open or shorted.)
 Heated oxygen sensor 2 heater
P0057
0057
(Bank 2)
P0038
0038
(Bank 1)
Heated oxygen
sensor 2 heater
control circuit high The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater circuit is
shorted.)
 Heated oxygen sensor 2 heater
P0058
0058
(Bank 2)
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0101 MAF SENSOREC-761
< SERVICE INFORMATION > [VK45DE]
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DTC P0101 MAF SENSOR
Component DescriptionINFOID:0000000001326586
The mass air flow sensor is placed in
the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. The mass air flow sensor c ontrols the temperature of the hot
wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, the electric current supplied to hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000001326587
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001326588
DTC Confirmation ProcedureINFOID:0000000001326589
Perform PROCEDURE FOR MALFUNCTION A first.
If DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
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.
PROCEDURE FOR MALFUNCTION A
NOTE:
PBIB1604E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-709
.
CAL/LD VALUE  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 2.0 - 6.0 g·m/s
2,500 rpm 7.0 - 20.0 g·m/s
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0101
0101 Mass air flow sensor cir-
cuit range/performance A)
A high voltage from the sensor is sent to ECM
under light load driving condition.  Harness or connectors
(The sensor circuit is open or
shorted.)
 Mass air flow sensor
 EVAP control system pressure
sensor
 Intake air temperature sensor
B) A low voltage from the sensor is sent to ECM un-
der heavy load driving condition.  Harness or connectors
(The sensor circuit is open or
shorted.)
 Intake air leaks
 Mass air flow sensor
 EVAP control system pressure sensor
 Intake air temperature sensor
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-766
< SERVICE INFORMATION >[VK45DE]
DTC P0101 MAF SENSOR
8.CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-778, "
Component Inspection".
OK or NG
OK >> GO TO 9.
NG >> Replace intake air temperature sensor.
9.CHECK EVAP CONTROL SY STEM PRESSURE SENSOR
Refer to EC-958, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10.CHECK MASS AIR FLOW SENSOR
Refer to EC-766, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> Replace mass air flow sensor.
11 .CHECK INTERMITTENT INCIDENT
Refer to EC-717
.
>> INSPECTION END
Component InspectionINFOID:0000000001326593
MASS AIR FLOW SENSOR
With CONSULT-III
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-III and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check i ndication under the following conditions.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
5. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.  Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system parts
b. If NG, repair or replace malfunc tioning part and perform step 2 to 4 again.
If OK, go to next step.
6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor harness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.) 1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.) 1.6 - 2.0
Idle to about 4,000 rpm 1.0 - 1.3 to Approx. 2.4*
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-861
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DTC P0171, P0174 FUEL IN
JECTION SYSTEM FUNCTION
On Board Diagnosis LogicINFOID:0000000001326698
With the Air-Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the air fuel ratio (A/F) sensor 1. The
ECM calculates the necessary compensation to corre ct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extrem ely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation ProcedureINFOID:0000000001326699
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. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON- SULT-III.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Start engine. If it is difficult to start engine, t he fuel injection system has a malfunction.
Perform the following procedure is advised.
a. Crank engine while depressing accelerator pedal.
b. If engine starts, go to EC-866, "
Diagnosis Procedure".
If engine does not start, check exhaust and intake air leak visually.
6. Keep engine at idle for at least 10 minutes.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-866, "
Diagnosis Procedure".
If 1st trip DTC is not detected, per forming the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar condi tions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
Sensor Input Signal to ECM ECM function Actuator
A/F sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0171
0171
(Bank 1) Fuel injection system too
lean  Fuel injection system does not operate properly.
 The amount of mixture ratio compensation is too
large. (The mixture ratio is too lean.)  Intake air leaks
 A/F sensor 1
 Fuel injector
 Exhaust gas leaks
 Incorrect fuel pressure
 Lack of fuel
 Mass air flow sensor
 Incorrect PCV hose connection
P0174
0174
(Bank 2)
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-871
< SERVICE INFORMATION > [VK45DE]
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DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
On Board Diagnosis LogicINFOID:0000000001326702
With the Air-Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the air fuel ratio (A/F) sensor 1. The
ECM calculates the necessary compensation to corre ct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extrem ely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation ProcedureINFOID:0000000001326703
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. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON- SULT-III.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Start engine. If it is difficult to start engine, t he fuel injection system has a malfunction.
Perform the following procedure is advised.
a. Crank engine while depressing accelerator pedal.
b. If engine starts, go to EC-866, "
Diagnosis Procedure".
If engine does not start, remove ignition plugs and check for fouling, etc.
6. Keep engine at idle for at least 10 minutes.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-866, "
Diagnosis Procedure".
If 1st trip DTC is not detected, per forming the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar condi tions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
Sensor Input Signal to ECM ECM function Actuator
A/F sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0172
0172
(Bank 1) Fuel injection system too
rich  Fuel injection system does not operate properly.
 The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.)  A/F sensor 1
 Fuel injector
 Exhaust gas leaks
 Incorrect fuel pressure
 Mass air flow sensor
P0175
0175
(Bank 2)
Engine speed Engine speed in the freeze frame data
± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
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EC-922
< SERVICE INFORMATION >[VK45DE]
DTC P0441 EVAP CONTROL SYSTEM
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and let it idle for at least 70 seconds.
4. Select “PURG FLOW P0441” of “EVAPORATIVE
SYSTEM” in “DTC WORK SUPPORT” mode with CON-
SULT-III.
5. Touch “START”. If “COMPLETED” is displayed, go to step 7.
6. When the following conditions are met, “TESTING” will be displayed on the CONSULT-III screen. Maintain
the conditions continuously until “TESTING” changes to “COMPLETED”. (It will take at least 35 seconds.)
If “TESTING” is not changed for a long time, retry from step 2.
7. Make sure that “OK” is displayed after touching “ SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-
922, "Diagnosis Procedure".
Overall Function CheckINFOID:0000000001326761
Use this procedure to check the overall monitoring func tion of the EVAP control system purge flow monitoring.
During this check, a 1st trip DTC might not be confirmed.
WITH GST
1. Lift up drive wheels.
2. Start engine (VDC switch OFF) and warm it up to normal operating temperature.
3. Turn ignition switch OFF, wait at least 10 seconds.
4. Start engine and wait at least 70 seconds.
5. Set voltmeter probes to ECM terminals 32 (EVAP control system pressure sensor signal) and ground.
6. Check EVAP control system pre ssure sensor value at idle speed
and note it.
7. Establish and maintain the following conditions for at least 1 minute.
8. Verify that EVAP control system pressure sensor va lue stays 0.1V less than the value at idle speed (mea-
sured at step 6) for at least 1 second.
9. If NG, go to EC-922, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001326762
1.CHECK EVAP CANISTER
1. Turn ignition switch OFF.
2. Check EVAP canister for cracks.
OK or NG
OK (With CONSULT-III)>>GO TO 2.
OK (Without CONSULT-III)>>GO TO 3.
NG >> Replace EVAP canister.
Selector lever Suitable position
VHCL SPEED SE 32 - 120 km/h (20 - 75 MPH)
ENG SPEED 500 - 3,000 rpm
B/FUEL SCHDL 1.0 - 10.0 msec
COOLAN TEMP/S 70 - 100 °C (158 - 212 °F)
Air conditioner switch ON
Headlamp switch ON
Rear window defogger switch ON
Engine speed Approx. 3,000 rpm
Gear position Any position other than P, N or R
PBIB1109E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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