ecm INFINITI M35 2007 Factory Owners Manual

EC-32
[VQ35DE]
ENGINE CONTROL SYSTEM
Revision: 2007 April2007 M35/M45
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 1 can then better reduce CO, HC and NOx emissions. This system uses A/F 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 A/F sensor 1, refer to EC-244,
"DTC P0131, P0151 A/F SENSOR 1" . 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 1. Even if the switching characteris-
tics of A/F sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal from heated oxygen sen-
sor 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 A/F sensor 1 or its circuit

Insufficient activation of A/F 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 A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-
ing operation (i.e., fuel 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 A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-
oretical 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.
PBIB3020E

ENGINE CONTROL SYSTEM
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Revision: 2007 April2007 M35/M45
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all six cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The six fuel injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration, operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speeds.
Electronic Ignition (EI) SystemNBS004S4
INPUT/OUTPUT SIGNAL CHART
*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 DESCRIPTION
Firing order: 1 - 2 - 3 - 4 - 5 - 6
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor (PHASE) sig-
nal. Computing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is revised by the ECM according to the other data stored in
the ECM.

At starting

During warm-up

At idle

At low battery voltage
SEF179U
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
2
Piston position
Ignition timing
controlPower transistor Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Battery
Battery voltage*
2
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Wheel sensor
Vehicle speed*
1

EC-34
[VQ35DE]
ENGINE CONTROL SYSTEM
Revision: 2007 April2007 M35/M45

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)NBS004S5
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,400 rpm under no load (for example, the selector lever position is neutral and
engine speed is over 1,400 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off var-
ies based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,000 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under Multiport Fuel Injection (MFI) System, 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-
trolFuel 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
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Revision: 2007 April2007 M35/M45
AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartNBS004S6
*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 DescriptionNBS004S7
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
Air conditioner ON signal*
1
Air conditioner
cut controlAir conditioner relay Accelerator pedal position sensor Accelerator pedal position
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
Vehicle speed*
1

EC-36
[VQ35DE]
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Revision: 2007 April2007 M35/M45
AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionNBS004S8
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 lamp and SET lamp in combination meter. If any malfunc-
tion occurs in ASCD system, it automatically deactivates control.
NOTE:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
SET OPERATION
Press MAIN switch. (The CRUISE lamp 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 lamp in combination meter illuminates.)
ACCELERATE 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 pressing 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.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switchGear position
Wheel sensor Vehicle speed*
TCM Powertrain revolution*

EVAPORATIVE EMISSION SYSTEM
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Revision: 2007 April2007 M35/M45
EVAPORATIVE EMISSION SYSTEMPFP:14950
DescriptionNBS004SB
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

IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS)
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IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS)PFP:28591
DescriptionNBS004SK

If the security indicator lights up with the ignition switch in
the ON position or “NATS MALFUNCTION” is displayed on
“SELF-DIAG RESULTS” screen, perform self-diagnostic
results mode with CONSULT-II using NATS program card.
Refer to BL-244, "
IVIS (INFINITI VEHICLE IMMOBILIZER
SYSTEM-NATS)" .

Confirm no self-diagnostic results of IVIS (NATS) is dis-
played before touching “ERASE” in “SELF-DIAG RESULTS”
mode with CONSULT-II.

When replacing ECM, initialization of IVIS (NATS) system
and registration of all IVIS (NATS) ignition key IDs must be
carried out with CONSULT-II using NATS program card.
Therefore, be sure to receive all keys from vehicle owner. Regarding the procedures of IVIS (NATS)
initialization and all IVIS (NATS) ignition key ID registration, refer to CONSULT-II Operation Manual,
IVIS/NVIS.
SEF543X

EC-54
[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2007 April2007 M35/M45
ON BOARD DIAGNOSTIC (OBD) SYSTEMPFP:00028
IntroductionNBS004SL
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-98,
"Fail-Safe Chart" .)
Two Trip Detection LogicNBS004SM
When a malfunction is detected for the first 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.
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 DTCFreeze
Frame data1st trip Freeze
Frame dataSRT code SRT status Test value
CONSULT-II×× × × × ×—
GST×× ×—×××
ECM××*— — —×—
ItemsMIL DTC 1st trip DTC
1st trip 2nd trip
1st trip
displaying2nd trip
displaying1st trip
displaying2nd trip
display-
ing BlinkingLighting
upBlinkingLighting
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-55, "
EMISSION-
RELATED DIAGNOSTIC INFOR-
MATION ITEMS" .)—×——×———
Except above — — —×—××—

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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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.
Emission-Related Diagnostic InformationNBS004SN
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS
×:Applicable —: Not applicable Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
Items
(CONSULT-II screen terms)DTC*
1
SRT codeTest value/
Test limit
(GST only)Trip MIL Reference page
CONSULT-II
GST*
2ECM*3
CAN COMM CIRCUIT U1000
1000*4—— 1×EC-161
CAN COMM CIRCUIT U1001
1001*4——2 (Models with
ASCD)
—EC-1611 or 2 (Models
with ICC)
CONTROL UNIT(CAN) U1010 1010 — — 1×EC-164
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.P0000 0000—— —Flas
hing
*
8—
INT/V TIM CONT-B1 P0011 0011 — — 2×EC-166
INT/V TIM CONT-B2 P0021 0021 — — 2×EC-166
A/F SEN1 HTR (B1) P0031 0031 —×2×EC-170
A/F SEN1 HTR (B1) P0032 0032 —×2×EC-170
HO2S2 HTR (B1) P0037 0037 —×2×EC-177
HO2S2 HTR (B1) P0038 0038 —×2×EC-177
A/F SEN1 HTR (B2) P0051 0051 —×2×EC-170
A/F SEN1 HTR (B2) P0052 0052 —×2×EC-170
HO2S2 HTR (B2) P0057 0057 —×2×EC-177
HO2S2 HTR (B2) P0058 0058 —×2×EC-177
INT/V TIM V/CIR-B1 P0075 0075 — — 2×EC-185
INT/V TIM V/CIR-B2 P0081 0081 — — 2×EC-185
MAF SEN/CIRCUIT P0101 0101 — — 2×EC-193
MAF SEN/CIRCUIT P0102 0102 — — 1×EC-202
MAF SEN/CIRCUIT P0103 0103 — — 1×EC-202
IAT SEN/CIRCUIT P0112 0112 — — 2×EC-209
IAT SEN/CIRCUIT P0113 0113 — — 2×EC-209
ECT SEN/CIRC P0117 0117 — — 1×EC-214
ECT SEN/CIRC P0118 0118 — — 1×EC-214
TP SEN 2/CIRC P0122 0122 — — 1×EC-219
TP SEN 2/CIRC P0123 0123 — — 1×EC-219
ECT SENSOR P0125 0125 — — 2×EC-226
IAT SENSOR P0127 0127 — — 2×EC-229
THERMSTAT FNCTN P0128 0128 — — 2×EC-232
A/F SENSOR1 (B1) P0130 0130 —×2×EC-234
A/F SENSOR1 (B1) P0131 0131 —×2×EC-244
A/F SENSOR1 (B1) P0132 0132 —×2×EC-253

EC-56
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2007 April2007 M35/M45
A/F SENSOR1 (B1) P0133 0133××2×EC-262
HO2S2 (B1) P0137 0137××2×EC-274
HO2S2 (B1) P0138 0138××2×EC-285
HO2S2 (B1) P0139 0139××2×EC-298
A/F SENSOR1 (B2) P0150 0150 —×2×EC-234
A/F SENSOR1 (B2) P0151 0151 —×2×EC-244
A/F SENSOR1 (B2) P0152 0152 —×2×EC-253
A/F SENSOR1 (B2) P0153 0153××2×EC-262
HO2S2 (B2) P0157 0157××2×EC-274
HO2S2 (B2) P0158 0158××2×EC-285
HO2S2 (B2) P0159 0159××2×EC-298
FUEL SYS-LEAN-B1 P0171 0171 — — 2×EC-309
FUEL SYS-RICH-B1 P0172 0172 — — 2×EC-320
FUEL SYS-LEAN-B2 P0174 0174 — — 2×EC-309
FUEL SYS-RICH-B2 P0175 0175 — — 2×EC-320
FTT SENSOR P0181 0181 — — 2×EC-331
FTT SEN/CIRCUIT P0182 0182 — — 2×EC-337
FTT SEN/CIRCUIT P0183 0183 — — 2×EC-337
TP SEN 1/CIRC P0222 0222 — — 1×EC-342
TP SEN 1/CIRC P0223 0223 — — 1×EC-342
MULTI CYL MISFIRE P0300 0300 — — 2×EC-349
CYL 1 MISFIRE P0301 0301 — — 2×EC-349
CYL 2 MISFIRE P0302 0302 — — 2×EC-349
CYL 3 MISFIRE P0303 0303 — — 2×EC-349
CYL 4 MISFIRE P0304 0304 — — 2×EC-349
CYL 5 MISFIRE P0305 0305 — — 2×EC-349
CYL 6 MISFIRE P0306 0306 — — 2×EC-349
KNOCK SEN/CIRC-B1 P0327 0327 — — 2 —EC-359
KNOCK SEN/CIRC-B1 P0328 0328 — — 2 —EC-359
CKP SEN/CIRCUIT P0335 0335 — — 2×EC-364
CMP SEN/CIRC-B1 P0340 0340 — — 2×EC-371
CMP SEN/CIRC-B2 P0345 0345 — — 2×EC-371
TW CATALYST SYS-B1 P0420 0420××2×EC-380
TW CATALYST SYS-B2 P0430 0430××2×EC-380
EVAP PURG FLOW/MON P0441 0441××2×EC-386
EVAP SMALL LEAK P0442 0442××2×EC-391
PURG VOLUME CONT/V P0443 0443 — — 2×EC-400
PURG VOLUME CONT/V P0444 0444 — — 2×EC-408
PURG VOLUME CONT/V P0445 0445 — — 2×EC-408
VENT CONTROL VALVE P0447 0447 — — 2×EC-415
VENT CONTROL VALVE P0448 0448 — — 2×EC-422
EVAP SYS PRES SEN P0451 0451 — — 2×EC-428
Items
(CONSULT-II screen terms)DTC*
1
SRT codeTest value/
Te s t l i m i t
(GST only)Trip MIL Reference page
CONSULT-II
GST*
2ECM*3