EC engine control system INFINITI FX35 2005 Service Manual

EC-34
[VQ35DE]
ENGINE CONTROL SYSTEM
Revision: 2005 July 2005 FX

During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Fuel Cut Control (at No Load and High Engine Speed)ABS006KA
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed is over 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under EC-31, "
Multiport Fuel Injection (MFI) System" .
Sensor Input Signal to ECM ECM function Actuator
Park/neutral position (PNP) switch Neutral position
Fuel cut con-
trol Fuel injector
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed
Wheel sensor* Vehicle speed

AIR CONDITIONING CUT CONTROL EC-35
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Revision: 2005 July 2005 FX
AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartABS00E8X
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
System DescriptionABS00E8Y
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.

When the accelerator pedal is fully depressed.

When cranking the engine.

At high engine speeds.

When the engine coolant temperature becomes excessively high.

When operating power steering during low engine speed or low vehicle speed.

When engine speed is excessively low.

When refrigerant pressure is excessively low or high.
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch*
1Air conditioner ON signal
Air conditioner
cut control Air conditioner relay
Accelerator pedal position sensor Accelerator pedal position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
2
Engine coolant temperature sensor Engine coolant temperature
Battery Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor*
1Vehicle speed

EC-36
[VQ35DE]
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Revision: 2005 July 2005 FX
AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionABS006ZG
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
SET OPERATION
Press MAIN switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press SET/COAST switch. (Then SET indicator in combination meter illuminates.)
ACCEL OPERATION
If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until
the switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.

CANCEL switch is pressed

More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)

Brake pedal is depressed

Selector lever is changed to N, P, R position

Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed

VDC/TCS system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.

Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by depressing SET/COAST switch or RESUME/
ACCELERATE switch.

Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled and vehicle
speed memory will be erased.
COAST OPERATION
When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed control Electric throttle control
actuator
Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switch Gear position
Unified meter and A/C amp.* Vehicle speed
TCM* Powertrain revolution

EVAPORATIVE EMISSION SYSTEM EC-39
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EVAPORATIVE EMISSION SYSTEMPFP:14950
DescriptionABS006Z7
SYSTEM DESCRIPTION
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating. EVAP canister purge volume control solenoid valve is controlled by ECM. When the
engine operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is
proportionally regulated as the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.
PBIB1631E

EVAPORATIVE EMISSION SYSTEM EC-43
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Revision: 2005 July 2005 FX
EVAP SERVICE PORT
Positive pressure is delivered to the EVAP system through the EVAP
service port. If fuel vapor leakage in the EVAP system occurs, use a
leak detector to locate the leak.
Removal and InstallationABS006Z9
EVAP CANISTER
Tighten EVAP canister as shown in the figure.
EVAP CANISTER VENT CONTROL VALVE
1. Turn EVAP canister vent control valve counterclockwise.
2. Remove the EVAP canister vent control valve.
Always replace O-ring with a new one.
How to Detect Fuel Vapor LeakageABS006ZA
CAUTION:

Never use compressed air or a high pressure pump.

Do not exceed 4.12 kPa (0.042 kg/cm2 , 0.6 psi) of pressure in EVAP system.
NOTE:

Do not start engine.

Improper installation of EVAP service port adapter to the EVAP service port may cause a leak.
SEF462UA
PBIB1029E
PBIB1030E

EC-54
[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2005 July 2005 FX
ON BOARD DIAGNOSTIC (OBD) SYSTEMPFP:00028
IntroductionABS006KI
The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-related diagnostic information including:
The above information can be checked using procedures listed in the table below.
× : Applicable —: Not applicable
*: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
The malfunction indicator lamp (MIL) on the instrument panel lights up when the same malfunction is detected
in two consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode. (Refer to EC-109
.)
Two Trip Detection LogicABS006KJ
When a malfunction is detected for the 1st time, 1st trip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not light up at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL lights up. The MIL lights up at the same time when the DTC is stored. <2nd
trip> The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation. Specific on board diagnostic items will cause the ECM to light up or blink the MIL,
and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
× : Applicable —: Not applicable
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.
Emission-related diagnostic information Diagnostic service
Diagnostic Trouble Code (DTC) Service $03 of SAE J1979
Freeze Frame data Service $02 of SAE J1979
System Readiness Test (SRT) code Service $01 of SAE J1979
1st Trip Diagnostic Trouble Code (1st Trip DTC) Service $07 of SAE J1979
1st Trip Freeze Frame data
Test values and Test limits Service $06 of SAE J1979
Calibration ID Service $09 of SAE J1979
DTC 1st trip DTC Freeze
Frame data 1st trip Freeze
Frame data SRT code SRT status Test value
CONSULT-II ×× × × × × —
GST ×× × —×××
ECM ××*— — — ×—
Items MIL DTC 1st trip DTC
1st trip 2nd trip 1st trip
displaying 2nd trip
displaying 1st trip
displaying 2nd trip
display- ing
Blinking Lighting
up Blinking Lighting
up
Misfire (Possible three way cata-
lyst damage) — DTC: P0300 -
P0306 is being detected ×
———— — ×—
Misfire (Possible three way cata-
lyst damage) — DTC: P0300 -
P0306 is being detected ——
×—— ×——
One trip detection diagnoses
(Refer to EC-15
.) —
×—— ×———
Except above — — — ×— ×× —

EC-56
[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2005 July 2005 FX
CYL 1 MISFIRE P0301 0301 — — 2 ×EC-285
CYL 2 MISFIRE P0302 0302 — — 2 ×EC-285
CYL 3 MISFIRE P0303 0303 — — 2 ×EC-285
CYL 4 MISFIRE P0304 0304 — — 2 ×EC-285
CYL 5 MISFIRE P0305 0305 — — 2 ×EC-285
CYL 6 MISFIRE P0306 0306 — — 2 ×EC-285
KNOCK SEN/CIRC-B1 P0327 0327 — — 2 — EC-295
KNOCK SEN/CIRC-B1 P0328 0328 — — 2 —EC-295
CKP SEN/CIRCUIT P0335 0335 — — 2×EC-300
CMP SEN/CIRC-B1 P0340 0340 — — 2 ×EC-307
CMP SEN/CIRC-B2 P0345 0345 — — 2 ×EC-307
TW CATALYST SYS-B1 P0420 0420 ××2×EC-316
TW CATALYST SYS-B2 P0430 0430 ××2×EC-316
EVAP PURG FLOW/MON P0441 0441 ××2×EC-322
EVAP SMALL LEAK P0442 0442 ××2×EC-327
PURG VOLUME CONT/V P0444 0444 — — 2 ×EC-336
PURG VOLUME CONT/V P0445 0445 — — 2 ×EC-336
VENT CONTROL VALVE P0447 0447 — — 2 ×EC-343
EVAP SYS PRES SEN P0451 0451 — — 2 ×EC-350
EVAP SYS PRES SEN P0452 0452 — — 2 ×EC-353
EVAP SYS PRES SEN P0453 0453 — — 2 ×EC-359
EVAP GROSS LEAK P0455 0455 — — 2 ×EC-367
EVAP VERY SML LEAK P0456 0456
× *4× 2 ×EC-375
FUEL LEV SEN SLOSH P0460 0460 — — 2 ×EC-385
FUEL LEVEL SENSOR P0461 0461 — — 2 ×EC-387
FUEL LEVL SEN/CIRC P0462 0462 — — 2 ×EC-389
FUEL LEVEL SEN/CIRC P0463 0463 — — 2 ×EC-389
VEH SPEED SEN/CIRC*6P0500 0500 — — 2 ×EC-391
ISC SYSTEM P0506 0506 — — 2 ×EC-393
ISC SYSTEM P0507 0507 — — 2 ×EC-395
PW ST P SEN/CIRC P0550 0550 — — 2 — EC-397
ECM P0605 0605 — — 1 or 2× or — EC-402
TCM P0700 0700 — — 1 ×AT- 11 3
PNP SW/CIRC P0705 0705 — — 2 ×AT- 11 4
ATF TEMP SEN/CIRC P0710 0710 — — 2 ×AT-136
VEH SPD SEN/CIR AT*6P0720 0720 — — 2 ×AT- 11 8
ENGINE SPEED SIG P0725 0725 — — 2 ×AT-123
TCC SOLENOID/CIRC P0740 0740 — — 2 ×AT-125
A/T TCC S/V FNCTN P0744 0744 — — 2 ×AT-127
L/PRESS SOL/CIRC P0745 0745 — — 2 ×AT-129
A/F SEN1 HTR (B1) P1031 1031 ××2×EC-405
A/F SEN1 HTR (B1) P1032 1032 ××2×EC-405
Items
(CONSULT-II screen terms) DTC*
1
SRT code
Test value/
Test limit
(GST only) Trip
Reference
page
CONSULT-II
GST*
2ECM*3

ON BOARD DIAGNOSTIC (OBD) SYSTEM EC-59
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Revision: 2005 July 2005 FX
For malfunctions in which 1st trip DTCs are displayed, refer to EC-55, "EMISSION-RELATED DIAGNOSTIC
INFORMATION ITEMS" . These items are required by legal regulations to continuously monitor the system/
component. In addition, the items monitored non-continuously are also displayed on CONSULT-II.
1st trip DTC is specified in Service $07 of SAE J1979. 1st trip DTC detection occurs without lighting up the MIL
and therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step II, refer to EC-102, "
WORK FLOW" . Then perform DTC Con-
firmation Procedure or Overall Function Check to try to duplicate the malfunction. If the malfunction is dupli-
cated, the item requires repair.
How to Read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.
With CONSULT-II
With GST
CONSULT-II or GST (Generic Scan Tool) Examples: P0340, P1148, P1706, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MIL in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0340, 1148, 1706, etc.
These DTCs are controlled by NISSAN.

1st trip DTC No. is the same as DTC No.

Output of a DTC indicates a malfunction. However, GST or the Diagnostic Test Mode II do not indi-
cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-II can identify malfunction status as shown below. Therefore, using CONSULT-II (if
available) is recommended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown below. DTC or 1st trip DTC of a malfunc-
tion is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-II. Time data indicates how many times
the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be [0].
If a 1st trip DTC is stored in the ECM, the time data will be [1t].
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, base fuel schedule and intake
air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
details, see EC-136, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
PBIB0911E

EC-68
[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2005 July 2005 FX
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION
How to Erase DTC
With CONSULT-II
The emission related diagnostic information in the ECM can be erased by selecting “ERASE” in the “SELF-
DIAG RESULTS” mode with CONSULT-II.
If DTCs are displayed for both ECM and TCM (Transmission control module), they need to be erased individu-
ally from the ECM and TCM (Transmission control module).
NOTE:
If the DTC is not for A/T related items (see EC-15
), skip steps 2 through 4.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10 seconds and then turn it ON (engine stopped) again.
2. Turn CONSULT-II ON and touch “A/T”.
3. Touch “SELF-DIAG RESULTS”.
4. Touch “ERASE”. [The DTC in the TCM (Transmission control module) will be erased.] Then touch “BACK” twice.
5. Touch “ENGINE”.
6. Touch “SELF-DIAG RESULTS”.
7. Touch “ERASE”. (The DTC in the ECM will be erased.)
With GST
The emission related diagnostic information in the ECM can be erased by selecting Service $04 with GST.
NOTE:
If the DTC is not for A/T related items (see EC-15
), skip step 2.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10 seconds and then turn it ON (engine stopped) again.
SCIA5671E

EC-70
[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2005 July 2005 FX
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following three functions.
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.
MIL Flashing Without DTC
When any SRT codes are not set, MIL may flash without DTC. For the details, refer to EC-63, "How to Display
SRT Status" .
HOW TO SWITCH DIAGNOSTIC TEST MODE
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.

Always ECM returns to Diagnostic Test Mode I after ignition switch is turned OFF.
How to Set Diagnostic Test Mode II (Self-Diagnostic Results)
1. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
2. Repeat the following procedure quickly 5 times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the MIL starts blinking.
Diagnostic Test
Mode KEY and ENG.
Sta tus Function Explanation of Function
Mode I Ignition switch in ON position
Engine stopped BULB CHECK This function checks the MIL bulb for damage (blown,
open circuit, etc.).
If the MIL does not come on, check MIL circuit.
Engine running MALFUNCTION WARNING This is a usual driving condition. When a malfunction is
detected twice in two consecutive driving cycles (two trip
detection logic), the MIL will light up to inform the driver
that a malfunction has been detected.
The following malfunctions will light up or blink the MIL in
the 1st trip.

Misfire (Possible three way catalyst damage)

One trip detection diagnoses
Mode II Ignition switch in ON position
Engine stopped SELF-DIAGNOSTIC
RESULTS This function allows DTCs and 1st trip DTCs to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut