stop start INFINITI FX35 2005 Service Manual

ENGINE CONTROL SYSTEM EC-723
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Revision: 2005 July 2005 FX
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses
heated oxygen sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about
heated oxygen sensor 1, refer to EC-935
. This maintains the mixture ratio within the range of stoichiometric
(ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.

Deceleration and acceleration

High-load, high-speed operation

Malfunction of heated oxygen sensor 1 or its circuit

Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature

High engine coolant temperature

During warm-up

After shifting from N to D

When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from heated oxygen
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from heated oxygen sensor 1 indicates whether the mixture ratio is RICH or LEAN compared
to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an
increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
PBIB0121E

EC-772
[VK45DE]
BASIC SERVICE PROCEDURE
Revision: 2005 July 2005 FX
10. CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light. Refer to EC-774
.
OK or NG
OK >> GO TO 19.
NG >> GO TO 11.
11 . PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-786, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-786, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-787, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II. Refer to EC-774
.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed. Refer to EC-774
.
OK or NG
OK >> GO TO 15.
NG >> GO TO 17. 12
± 5 ° BTDC (in P or N position)
PBIB1487E
650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
SEF174Y

EC-780
[VK45DE]
BASIC SERVICE PROCEDURE
Revision: 2005 July 2005 FX
10. CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light. Refer to EC-774
.
OK or NG
OK (With CONSULT-II)>>GO TO 19.
OK (Without CONSULT-II)>>GO TO 20.
NG >> GO TO 11.
11 . PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-786, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-786, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Perform EC-787, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II. Refer to EC-774
.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed. Refer to EC-774
.
OK or NG
OK >> GO TO 15.
NG >> GO TO 17. 12
± 5 ° BTDC (in P or N position)
PBIB1487E
650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
SEF174Y

EC-782
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BASIC SERVICE PROCEDURE
Revision: 2005 July 2005 FX
19. CHECK HEATED OXYGEN SENSOR 1 (BANK 1) SIGNAL
With CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. See “HO2S1 MNTR (B1)” in “DATA MONITOR” mode.
3. Running engine at 2,000 rpm under no load (The engine is warmed up to normal operating temperature.), check that the
monitor fluctuates between LEAN and RICH more than 5 times
during 10 seconds.
OK or NG
OK >> GO TO 21.
NG (Monitor does not fluctuate.)>>GO TO 23.
NG (Monitor fluctuates less than 5 times.)>>GO TO 31.
20. CHECK HEATED OXYGEN SENSOR 1 (BANK 1) SIGNAL
Without CONSULT-II
1. Stop engine and set ECM to Self Diagnostic Test Mode II (Heated oxygen sensor 1 monitor). Refer to EC-
762, "HOW TO SWITCH DIAGNOSTIC TEST MODE" .
2. Start engine and run it at about 2,000 rpm for about 2 minutes under no load.
3. Running engine at 2,000 rpm under no load (The engine is warmed up to normal operating temperature.), check that the MIL comes on more than 5 times during 10 seconds.
OK or NG
OK >> GO TO 22.
NG (MIL does not come on)>>GO TO 23.
NG (MIL comes on less than 5 times)>>GO TO 31.
21. CHECK HEATED OXYGEN SENSOR 1 (BANK 2) SIGNAL
With CONSULT-II
1. See “HO2S1 MNTR (B2)” in “DATA MONITOR” mode.
2. Running engine at 2,000 rpm under no load (The engine is warmed up to normal operating temperature.), check that the
monitor fluctuates between LEAN and RICH more than 5 times
during 10 seconds.
OK or NG
OK >> INSPECTION END
NG (Monitor does not fluctuate.)>>GO TO 24.
NG (Monitor fluctuates less than 5 times.)>>GO TO 31. 1 time: RICH
→ LEAN → RICH
2 times: RICH → LEAN → RICH → LEAN → RICH
PBIB0120E
1 time: RICH → LEAN → RICH
2 times: RICH → LEAN → RICH → LEAN → RICH
PBIB0120E

BASIC SERVICE PROCEDURE EC-785
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31. REPLACE HEATED OXYGEN SENSOR 1
1. Stop engine.
2. Replace heated oxygen sensor 1 on the malfunctioning bank.
With CONSULT-II>>GO TO 32.
Without CONSULT-II>>GO TO 33.
32. CHECK HEATED OXYGEN SENSOR 1 (BANK 1) / (BANK 2) SIGNAL
With CONSULT-II
1. Start engine and warm it up until engine coolant temperature indicator points the middle of gauge.
2. See “HO2S1 MNTR (B1)/(B2)” in “DATA MONITOR” mode.
3. Running engine at 2,000 rpm under no load (The engine is warmed up to normal operating temperature.), check that the
monitor fluctuates between LEAN and RICH more than 5 times
during 10 seconds.
OK or NG
OK >> GO TO 4.
NG >> GO TO 34.
33. CHECK HEATED OXYGEN SENSOR 1 (BANK 1) / (BANK 2) SIGNAL
Without CONSULT-II
1. Set ECM to Self Diagnostic Test Mode II (Heated oxygen sensor 1 monitor). Refer to EC-762, "
HOW TO
SWITCH DIAGNOSTIC TEST MODE" .
2. Switch the monitored sensor to the malfunctioning bank. Refer to EC-762, "
How to Switch Monitored Sen-
sor From Bank 1 to Bank 2 or Vice Versa" .
3. Running engine at 2,000 rpm under no load (The engine is warmed up to normal operating temperature.), check that the MIL comes on more than 5 times during 10 seconds.
OK or NG
OK >> GO TO 4.
NG >> GO TO 34.
34. DETECT MALFUNCTIONING PART
Check the following.

Check fuel pressure regulator and repair or replace if necessary. Refer to EC-789 .

Check mass air flow sensor and its circuit, and repair or replace if necessary. Refer to EC-902 .

Check injector and its circuit, and repair or replace if necessary. Refer to EC-1351 .

Check engine coolant temperature sensor and its circuit, and repair or replace if necessary. Refer to EC-
914 and EC-927 .
OK or NG
OK >> GO TO 36.
NG >> 1. Repair or replace.
2. GO TO 35.
1 time: RICH
→ LEAN → RICH
2 times: RICH → LEAN → RICH → LEAN → RICH
SEF449Y

BASIC SERVICE PROCEDURE EC-787
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Revision: 2005 July 2005 FX
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds. Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningABS00E4I
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:

Each time electric throttle control actuator or ECM is replaced.

Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.

Battery voltage: More than 12.9V (At idle)

Engine coolant temperature: 70 - 99 °C (158 - 210 °F)

PNP switch: ON

Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine
is started the headlamp will not be illuminated.

Steering wheel: Neutral (Straight-ahead position)

Vehicle speed: Stopped

Transmission: Warmed-up
For models with CONSULT-II, drive vehicle until “ATF TEMP SE 1” in “DATA MONITOR” mode of “A/T”
system indicates less than 0.9V.
For models without CONSULT-II, drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-786, "Accelerator Pedal Released Position Learning" .
2. Perform EC-786, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
SEF217Z

EC-788
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BASIC SERVICE PROCEDURE
Revision: 2005 July 2005 FX
6. Touch “START” and wait 20 seconds.
7. Make sure that “CMPLT” is displayed on CONSULT-II screen. If “CMPLT” is not displayed, Idle Air Volume Learning will not be
carried out successfully. In this case, find the cause of the inci-
dent by referring to the DIAGNOSTIC PROCEDURE below.
8. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifications.
Without CONSULT-II
NOTE:

It is better to count the time accurately with a clock.

It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
1. Perform EC-786, "
Accelerator Pedal Released Position Learning" .
2. Perform EC-786, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifications.
SEF454Y
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 12 ± 5 ° BTDC (in P or N position)
MBIB0238E
SEC897C

TROUBLE DIAGNOSIS EC-799
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Revision: 2005 July 2005 FX
Fail-Safe ChartABS007I0
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.

When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when
there is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands
the driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine coolant temperature will be determined by ECM based on the time after turning
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or START 40
°C (104 °F)
More than approx. 4 minutes after
ignition ON or START 80
°C (176 °F)
Except as shown above 40 - 80
°C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135 Throttle position sensor 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.
P1121 Electric throttle control actuator (When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops,
the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P1122 Electric throttle control function ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1124
P1126 Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1128 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P1229 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal position
sensor 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.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

TROUBLE DIAGNOSIS EC-825
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Revision: 2005 July 2005 FX
4. Touch “START (NISSAN BASED VHCL)”.
5. Touch “ENGINE”.
If “ENGINE” is not indicated, go to GI-39, "
CONSULT-II Data
Link Connector (DLC) Circuit" .
6. Perform each diagnostic test mode according to each service procedure.
For further information, see the CONSULT-II Operation Manual.
WORK SUPPORT MODE
Work Item
BCIA0029E
BCIA0030E
BCIA0031E
WORK ITEM CONDITION USAGE
FUEL PRESSURE RELEASE

FUEL PUMP WILL STOP BY TOUCHING “START” DUR-
ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS. When releasing fuel pressure
from fuel line
IDLE AIR VOL LEARN

THE IDLE AIR VOLUME THAT KEEPS THE ENGINE
WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM. When learning the idle air volume
SELF-LEARNING CONT

THE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT. When clearing the coefficient of
self-learning control value

EC-828
[VK45DE]
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
BATTERY VOLT
[V] ××
The power supply voltage of ECM is dis-
played.
ACCEL SEN 1 [V] ××

The accelerator pedal position sensor
signal voltage is displayed.
ACCEL SENS2 signal is converted be
ECM internally. Thus, they differs from
ECM terminal voltage signal.
ACCEL SEN 2 [V]
×
THRTL SEN 1 [V] ××

The throttle position sensor signal voltage
is displayed.
THRTL SEN 2 signal is converted by
ECM internally. Thus, they differs from
ECM terminal voltage signal.
THRTL SEN 2 [V]
×
FUEL T/TMP SE
[ ° C] or [ °F] ×

The fuel temperature (determined by the
signal voltage of the fuel tank tempera-
ture sensor) is displayed.
INT/A TEMP SE
[ ° C] or [ °F] ××

The intake air temperature (determined
by the signal voltage of the intake air tem-
perature sensor) is indicated.
EVAP SYS PRES
[V] ×

The signal voltage of EVAP control sys-
tem pressure sensor is displayed.
FUEL LEVEL SE
[V] ×

The signal voltage of the fuel level sensor
is displayed.
START SIGNAL
[ON/OFF] ××

Indicates start signal status [ON/OFF]
computed by the ECM according to the
signals of engine speed and battery volt-
age.

After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF] ××

Indicates idle position [ON/OFF] com-
puted by ECM according to the accelera-
tor pedal position sensor signal.
AIR COND SIG
[ON/OFF] ××

Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
P/N POSI SW
[ON/OFF] ××

Indicates [ON/OFF] condition from the
park/neutral position (PNP) switch signal.
PW/ST SIGNAL
[ON/OFF] ××

[ON/OFF] condition of the power steering
system (determined by the signal voltage
of the power steering pressure sensor
signal) is indicated.
LOAD SIGNAL
[ON/OFF] ××

Indicates [ON/OFF] condition from the
electrical load signal.
ON: Rear window defogger switch is ON
and/or lighting switch is in 2nd position.
OFF: Both rear window defogger switch
and lighting switch are OFF.
IGNITION SW
[ON/OFF] ×

Indicates [ON/OFF] condition from igni-
tion switch signal.
HEATER FAN SW
[ON/OFF] ×

Indicates [ON/OFF] condition from the
heater fan switch signal.
BRAKE SW
[ON/OFF]

Indicates [ON/OFF] condition from the
stop lamp switch signal.
INJ PULSE-B1
[msec] ×

Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals.
When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING
[BTDC] ×

Indicates the ignition timing computed by
ECM according to the input signals.
When the engine is stopped, a certain
value is indicated.
Monitored item
[Unit] ECM
INPUT SIG-
NALS MAIN
SIG-
NALS Description Remarks