2007 NISSAN 350Z width

EC-26
ENGINE CONTROL SYSTEM
Revision: 2006 November2007 350Z

When selector lever is changed from N to D (A/T models)

High-load, high-speed operation


During deceleration

During high engine speed operation
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 air fuel ratio
(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 air fuel
ratio (A/F) sensor 1, refer to EC-257, "
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 air fuel ratio (A/F) 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 air fuel ratio (A/F) sensor 1 or its circuit

Insufficient activation of air fuel ratio (A/F) sensor 1 at low engine coolant temperature

High engine coolant temperature

During warm-up

After shifting from N to D (A/T models)

When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from air fuel ratio (A/F)
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., 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 air fuel ratio (A/F) sensor 1 indicates whether the mixture ratio is RICH or LEAN com-
pared 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.
PBIB3020E

ENGINE CONTROL SYSTEM
EC-27
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Revision: 2006 November2007 350Z
“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.
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) SystemNBS0002J
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
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
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor
Vehicle speed*1

EC-120
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
*: This item is the same as that of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×: Applicable ENGINE SPEED
[rpm]

The engine speed at the moment a malfunction is detected is displayed.
VEHICL SPEED
[km/h] or [mph]

The vehicle speed at the moment a malfunction is detected is displayed.
ABSOL TH-P/S [%]

The throttle valve operating angle at the moment a malfunction is detected is displayed.
B/FUEL SCHDL
[msec]

The base fuel schedule at the moment a malfunction is detected is displayed.
INT/A TEMP SE
[°C] or [°F]

The intake air temperature at the moment a malfunction is detected is displayed. Freeze frame data
item*Description
Monitored item [Unit] Description Remarks
ENG SPEED [rpm]

Indicates the engine speed computed from the signals
of the crankshaft position sensor (POS) and camshaft
position sensor (PHASE).
Accuracy becomes poor if engine speed drops
below the idle rpm.

If the signal is interrupted while the engine is
running, an abnormal value may be indicated.
MAS A/F SE-B1 [V]

The signal voltage of the mass air flow sensor is dis-
played.

When the engine is stopped, a certain value is
indicated.

When engine is running specification range is
indicated in “SPEC”. MAS A/F SE-B2 [V]
B/FUEL SCHDL [msec]

“Base fuel schedule” indicates the fuel injection pulse
width programmed into ECM, prior to any learned on
board correction.
When engine is running specification range is
indicated in “SPEC”.
A/F ALPHA-B1 [%]

The mean value of the air-fuel ratio feedback correc-
tion factor per cycle is indicated.

When the engine is stopped, a certain value is
indicated.

This data also includes the data for the air-fuel
ratio learning control.

When engine is running specification range is
indicated in “SPEC”. A/F ALPHA-B2 [%]
COOLAN TEMP/S [°C]
or [°F]

The engine coolant temperature (determined by the
signal voltage of the engine coolant temperature sen-
sor) is displayed.
When the engine coolant temperature sensor
is open or short-circuited, ECM enters fail-safe
mode. The engine coolant temperature deter-
mined by the ECM is displayed.
A/F SEN1 (B1) [V]

The A/F signal computed from the input signal of the
A/F sensor 1 is displayed.
A/F SEN1 (B2) [V]
HO2S2 (B1) [V]

The signal voltage of the heated oxygen sensor 2 is
displayed.
HO2S2 (B2) [V]
HO2S2 MNTR(B1)
[RICH/LEAN]

Display of heated oxygen sensor 2 signal:
RICH: Means the amount of oxygen after three way
catalyst is relatively small.
LEAN: Means the amount of oxygen after three way
catalyst is relatively large.

When the engine is stopped, a certain value is
indicated.
HO2S2 MNTR(B2)
[RICH/LEAN]
VHCL SPEED SE [km/
h] or [mph]

The vehicle speed computed from the vehicle speed
signal sent from combination meter is displayed.
BATTERY VOLT [V]

The power supply voltage of ECM is displayed.
ACCEL SEN 1 [V]

The accelerator pedal position sensor signal voltage is
displayed.
ACCEL SEN 2 signal is converted by ECM
internally. Thus, it differs from ECM terminal
voltage signal. ACCEL SEN 2 [V]

TROUBLE DIAGNOSIS
EC-121
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Revision: 2006 November2007 350Z
TP SEN 1-B1 [V]
The throttle position sensor signal voltage is dis-
played.
THRTL SEN 2-B1 signal is converted by ECM
internally. Thus, it differs from ECM terminal
voltage signal. TP SEN 2-B1 [V]
FUEL T/TMP SE [°C]
or [°F]

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

The intake air temperature (determined by the signal
voltage of the intake air temperature sensor) is indi-
cated.
EVAP SYS PRES [V]

The signal voltage of EVAP control system 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 voltage.
After starting the engine, [OFF] is displayed
regardless of the starter signal.
CLSD THL POS [ON/
OFF]

Indicates idle position [ON/OFF] computed by ECM
according to the accelerator pedal position sensor sig-
nal.
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 steer-
ing pressure sensor) is indicated.
LOAD SIGNAL [ON/
OFF]

Indicates [ON/OFF] condition from the electrical load
signal.
ON: Rear window defogger switch is ON and/or light-
ing 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 ignition switch sig-
nal.
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 compen-
sated by ECM according to the input signals.
When the engine is stopped, a certain com-
puted 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.
CAL/LD VALUE [%]

“Calculated load value” indicates the value of the cur-
rent air flow divided by peak air flow.
MASS AIRFLOW [g·m/
s]

Indicates the mass air flow computed by ECM accord-
ing to the signal voltage of the mass air flow sensor.
PURG VOL C/V [%]

Indicates the EVAP canister purge volume control
solenoid valve control value computed by the ECM
according to the input signals.

The opening becomes larger as the value increases.
INT/V TIM(B1) [°CA]

Indicates [°CA] of intake camshaft advanced angle.
INT/V TIM(B2) [°CA]
EXH/V TIM B1 [°CA]

Indicates [°CA] of exhaust camshaft retarded angle.
EXH/V TIM B2 [°CA] Monitored item [Unit] Description Remarks

TROUBLE DIAGNOSIS
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NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.VHCL SPEED SE [km/
h] or [mph]

The vehicle speed computed from the vehicle speed
signal sent from TCM is displayed.
SET VHCL SPD
[km/h] or [mph]

The preset vehicle speed is displayed.
MAIN SW
[ON/OFF]

Indicates [ON/OFF] condition from MAIN switch sig-
nal.
CANCEL SW
[ON/OFF]

Indicates [ON/OFF] condition from CANCEL switch
signal.
RESUME/ACC SW
[ON/OFF]

Indicates [ON/OFF] condition from RESUME/ACCEL-
ERATE switch signal.
SET SW
[ON/OFF]

Indicates [ON/OFF] condition from SET/COAST
switch signal.
BRAKE SW1
[ON/OFF]

Indicates [ON/OFF] condition from ASCD brake switch
signal and ASCD clutch switch signal (M/T)
BRAKE SW2
[ON/OFF]

Indicates [ON/OFF] condition of stop lamp switch sig-
nal.
VHCL SPD CUT
[NON/CUT]

Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the ASCD set
speed.
CUT: Vehicle speed decreased to excessively low
compared with the ASCD set speed, and ASCD oper-
ation is cut off.
LO SPEED CUT
[NON/CUT]

Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the ASCD set
speed.
CUT: Vehicle speed decreased to excessively low, and
ASCD operation is cut off.
AT OD MONITOR
[ON/OFF]

Indicates [ON/OFF] condition of A/T O/D according to
the input signal from the TCM.
For M/T models always “OFF” is displayed.
AT OD CANCEL
[ON/OFF]

Indicates [ON/OFF] condition of A/T O/D cancel
request signal.
For M/T models always “OFF” is displayed.
CRUISE LAMP
[ON/OFF]

Indicates [ON/OFF] condition of CRUISE lamp deter-
mined by the ECM according to the input signals.
SET LAMP
[ON/OFF]

Indicates [ON/OFF] condition of SET lamp determined
by the ECM according to the input signals.
EXH V/T LEARN [YET/
CMPLT]

Display the condition of Exhaust Valve Timing Control
Learning
YET: Exhaust Valve Timing Control Learning has not
been performed yet.
CMPLT: Exhaust Valve Timing Control Learning has
already been performed successfully.
A/F ADJ-B1

Indicates the correction of factor stored in ECM. The
factor is calculated from the difference between the
target air-fuel ratio stored in ECM and the air-fuel ratio
calculated from A/F sensor 1 signal. A/F ADJ-B2
Voltage [V]

Voltage, frequency, duty cycle or pulse width mea-
sured by the probe.

Only “#” is displayed if item is unable to be
measured.

Figures with “#”s are temporary ones. They
are the same figures as an actual piece of data
which was just previously measured. Frequency [msec], [Hz]
or [%]
DUTY-HI
DUTY-LOW
PLS WIDTH-HI
PLS WIDTH-LOWMonitored item [Unit] Description Remarks

EC-132
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Revision: 2006 November2007 350Z
TROUBLE DIAGNOSIS - SPECIFICATION VALUEPFP:00031
DescriptionNBS0003R
The specification (SP) value indicates the tolerance of the value that is displayed in “SPEC” in “DATA MONI-
TOR” mode of CONSULT-III during normal operation of the Engine Control System. When the value in “SPEC”
in “DATA MONITOR” mode is within the SP value, the Engine Control System is confirmed OK. When the
value in “SPEC” in “DATA MONITOR” mode is NOT within the SP value, the Engine Control System may have
one or more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:

B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)

A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)

MAS A/F SE-B1/B2 (The signal voltage of the mass air flow sensor)
Testing ConditionNBS0003S

Vehicle driven distance: More than 5,000 km (3,107 miles)

Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm2 , 14.25 - 15.12 psi)

Atmospheric temperature: 20 - 30°C (68 - 86°F)

Engine coolant temperature: 75 - 95°C (167 - 203°F)

Transmission: Warmed-up
–For A/T models: After the engine is warmed up to normal operating temperature, drive vehicle until “ATF
TEMP 1” (A/T fluid temperature sensor signal) indicates more than 60°C (140°F).
–For M/T models: After the engine is warmed up to normal operating temperature, drive vehicle for 5 min-
utes.

Electrical load: Not applied
–Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.

Engine speed: Idle
Inspection ProcedureNBS0003T
NOTE:
Perform “SPEC” in “DATA MONITOR” mode in maximum scale display.
1. Perform EC-71, "
Basic Inspection" .
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2”, “MAS A/F SE-B1” and “MAS A/F SE-B2” in
“SPEC” of ”DATA MONITOR” mode with CONSULT-III.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-133, "
Diagnostic Procedure" .

DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
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DTC P0075, P0081 IVT CONTROL SOLENOID VALVEPFP:23796
Component DescriptionNBS000BR
Intake valve timing control solenoid valve is activated by ON/OFF
pulse duty (ratio) signals from the ECM.
The intake valve timing 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.
CONSULT-III Reference Value in Data Monitor ModeNBS000BS
Specification data are reference values.
On Board Diagnosis LogicNBS000BT
DTC Confirmation ProcedureNBS000BU
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.
WITH CONSULT-III
1. Start engine and let it idle for 5 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-188, "
Diagnostic Procedure" .
WITH GST
Following the procedure “WITH CONSULT-III” above.
PBIB1842E
MONITOR ITEM CONDITION SPECIFICATION
INT/V SOL(B1)
INT/V SOL(B2)

Engine: After warming up

Shift lever: P or N (A/T), Neutral
(M/T)

Air conditioner switch: OFF

No loadIdle 0% - 2%
2,000 rpm Approx. 0% - 50%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0075
0075
(Bank 1)
Intake valve timing control
solenoid valve circuitAn improper voltage is sent to the ECM
through intake valve timing control solenoid
valve.

Harness or connectors
(The intake valve timing control solenoid
valve circuit is open or shorted.)

Intake valve timing control solenoid valve P0081
0081
(Bank 2)

EC-190
DTC P0078 P0084 EVT CONTROL MAGNET RETARDER
Revision: 2006 November2007 350Z
DTC P0078 P0084 EVT CONTROL MAGNET RETARDERPFP:23795
Component DescriptionNBS0004R
Exhaust valve timing control magnet retarder (1) controls the shut/
open timing of the exhaust valve by ON/OFF pulse duty signals sent
from the ECM.
The longer pulse width retards valve angle.
The shorter pulse width advances valve angle.
CONSULT-III Reference Value in Data Monitor ModeNBS0004S
Specification data are reference values.
On Board Diagnosis LogicNBS0004T
DTC Confirmation ProcedureNBS0004U
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-III
1. Start engine and let it idle for 5 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-195, "
Diagnostic Procedure" .
WITH GST
Following the procedure “WITH CONSULT-III” above.
PBIB3525E
MONITOR ITEM CONDITION SPECIFICATION
EX VTC DTY B1
EX VTC DTY B2

Engine: After warming up

Shift lever: Neutral

Air conditioner switch: OFF

No loadIdle 0% - 2%
Around 2,500 rpm while the engine
speed is risingApprox. 0% - 70%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0078
0078
(Bank 1)Exhaust valve timing con-
trol magnet retarder cir-
cuitAn improper voltage is sent to the ECM
through exhaust valve timing control magnet
retarder.

Harness or connectors
(Exhaust valve timing control magnet
retarder circuit is open or shorted.)

Exhaust valve timing control magnet
retarder P0084
0084
(Bank 2)