2007 NISSAN LATIO Lan system

CVT-70
DTC U1000 CAN COMMUNICATION LINE
Revision: June 20062007 Versa
TCM terminal data are reference values, measured between each terminal and ground.
Diagnostic ProcedureUCS005YP
1. CHECK CAN COMMUNICATION CIRCUIT
With CONSULT-II
1. Turn ignition switch ON and start engine.
2. Select “SELF-DIAG RESULTS” mode for “TRANSMISSION”
with CONSULT-II.
Is any malfunction of the
“U1000 CAN COMM CIRCUIT” indicated?
YES >> Print out CONSULT-II screen, go to LAN section. Refer
to LAN-47, "
CAN System Specification Chart" .
NO >>INSPECTION END
TerminalWire
colorItem Condition Data (Approx.)
5 L CAN-H — —
6 P CAN-L — —
SCIA5982E

DI-6
COMBINATION METERS
Revision: June 20062007 Versa

through grounds M57 and M61.
SPEEDOMETER
With ABS
The ABS actuator and electric unit (control unit) provides a vehicle speed signal to the combination meter via
CAN communication lines.
Without ABS or CVT
The vehicle speed sensor provides a vehicle speed signal to the combination meter for speedometer indica-
tion.
With CVT, Without ABS
The TCM provides a vehicle speed signal to the combination meter via CAN communication lines.
TACHOMETER
The tachometer indicates engine speed in revolutions per minute (rpm). The ECM provides an engine speed
signal to combination meter via CAN communication lines.
FUEL GAUGE
The fuel gauge indicates the approximate fuel level in the fuel tank.
The fuel gauge is regulated by the unified meter control unit and a variable resistor signal supplied

to combination meter terminal 24

through fuel level sensor unit and fuel pump terminal 5

through fuel level sensor unit and fuel pump terminal 2

from combination meter terminal 6.
ODO/TRIP METER
The vehicle speed signal and the memory signals from the meter memory circuit are processed by the combi-
nation meter and the mileage is displayed.
How to Change the Display
Refer to Owner's Manual for odo/trip meter operating instructions.
CAN COMMUNICATION SYSTEM DESCRIPTION
Refer to LAN-4, "SYSTEM DESCRIPTION" .
WKIA5370E
SKIB6904E

DI-22
COMBINATION METERS
Revision: June 20062007 Versa
Fuel Gauge Fluctuates, Indicates Wrong Value, or VariesEKS00I0K
1. CHECK FUEL GAUGE FLUCTUATION
Test drive vehicle to see if gauge fluctuates only during driving or at the instant of stopping.
Does the indication value vary only during driving or at the at the instant of stopping?
YES >> The pointer fluctuation may be caused by fuel level change in the fuel tank. Condition is normal.
NO >> Ask the customer about the situation when the symptom occurs in detail, and perform the trouble
diagnosis.
Fuel Gauge Does Not Move to Full positionEKS00I0L
1. OBSERVE FUEL GAUGE
Does it take a long time for the pointer to move to FULL position?
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2. IDENTIFY FUELING CONDITION
Was the vehicle fueled with the ignition switch ON?
YES or NO
YES >> Be sure to fuel the vehicle with the ignition switch OFF. Otherwise, it will take a long time to move
to FULL position because of the characteristic of the fuel gauge.
NO >> GO TO 3.
3. OBSERVE VEHICLE POSITION
Is the vehicle parked on an incline?
YES or NO
YES >> Check the fuel level indication with vehicle on a level surface.
NO >> GO TO 4.
4. OBSERVE FUEL GAUGE POINTER
During driving, does the fuel gauge pointer move gradually toward EMPTY position?
YES or NO
YES >> Check the components. Refer to DI-23, "FUEL LEVEL SENSOR UNIT CHECK" .
NO >> The float arm may interfere or bind with any of the components in the fuel tank.
DTC [U1000] CAN Communication CircuitEKS00IAR
Symptom: Display CAN COMM CIRC [U1000] at the result of self-diagnosis for combination meter.
1. CHECK CAN COMMUNICATION
1. Select "SELF-DIAG RESULTS" mode for "METER" with CONSULT-II.
2. Print out CONSULT-II screen.
>> Go to "CAN SYSTEM". Refer to LAN-44, "
TROUBLE DIAGNOSIS" .

DI-52
WARNING CHIME
Revision: June 20062007 Versa
Terminals and Reference Values for BCMEKS00I12
Refer to BCS-12, "Terminals and Reference Values for BCM" .
CONSULT-II Function (BCM)EKS00I13
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II START PROCEDURE
Refer to GI-38, "CONSULT-II Start Procedure" .
DATA MONITOR
Display Item List
ACTIVE TEST
Display Item List
SELF-DIAG RESULTS
Display Item List
NOTE:
If “CAN communication [U1000]” is indicated, after printing the monitor item, go to “LAN system”. Refer to
LAN-44, "
TROUBLE DIAGNOSIS" .
BCM diagnostic
test itemDiagnostic mode Description
Inspection by partWORK SUPPORTSupports inspections and adjustments. Commands are transmitted to the BCM
for setting the status suitable for required operation, input/output signals are
received from the BCM and received data is displayed.
DATA MONITOR Displays BCM input/output data in real time.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
SELF-DIAG RESULTS Displays BCM self-diagnosis results.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
ECU PART NUMBER BCM part number can be read.
CONFIGURATION Performs BCM configuration read/write functions.
Monitored item ALL SIGNALSSELECTION
FROM MENUContents
IGN ON SW X X Indicates [ON/OFF] condition of ignition switch.
KEY ON SW X X Indicates [ON/OFF] condition of key switch.
DOOR SW-DR X X Indicates [ON/OFF] condition of front door switch LH.
LIGHT SW 1ST X X Indicates [ON/OFF] condition of lighting switch.
BUCKLE SW X X Indicates [ON/OFF] condition of seat belt buckle switch LH.
Test item Malfunction is detected when···
IGN KEY WARN ALM This test is able to check key warning chime operation.
LIGHT WARN ALM This test is able to check light warning chime operation.
SEAT BELT WARN TEST This test is able to check seat belt warning chime operation.
Display item [Code] Malfunction is detected when...
CAN communication [U1000] Malfunction is detected in CAN communication.

PREPARATION
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Commercial Service ToolsUBS00PJQ
Tool number
(Kent-Moore No.)
Tool nameDescription
Leak detector
i.e.: (J-41416)Locating the EVAP leak
EVAP service port
adapter
i.e.: (J-41413-OBD)Applying positive pressure through EVAP service
port
Fuel filler cap adapter
i.e.: (MLR-8382)Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant tempera-
ture sensor
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12)Reconditioning the exhaust system threads before
installing a new oxygen sensor. Use with anti-
seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for Zirco-
nia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for Tita-
nia Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL specifica-
tion MIL-A-907)Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
S-NT703
S-NT704
S-NT815
S-NT705
AEM488
S-NT779

ENGINE CONTROL SYSTEM
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Multiport Fuel Injection (MFI) SystemUBS00PJS
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from the crankshaft position sensor (POS), camshaft position
sensor (PHASE) and the mass air flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.


During warm-up

When starting the engine

During acceleration

Hot-engine operation

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

High-load, high-speed operation


During deceleration

During high engine speed operation
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
3
Knock sensor Engine knocking condition
EPS control unit
Power steering operation*
2
Heated oxygen sensor 2*1Density of oxygen in exhaust gas
Air conditioner switch
Air conditioner operation*
2
Wheel sensor
Vehicle speed*2

EC-24Revision: June 2006
ENGINE CONTROL SYSTEM
2007 Versa
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 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-227, "
DTC P0131 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 (manifold). Even if the switching
characteristics 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 and CVT 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.
“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
EC-25
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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 four cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The four 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) SystemUBS00PJT
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 - 3 - 4 - 2
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
SEF 3 37 W
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