2006 NISSAN VERSA air condition

EC-1
ENGINE CONTROL SYSTEM
B ENGINE
CONTENTS
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SECTION EC
A
EC
Revision: June 20062007 Versa INDEX FOR DTC ........................................................ 8
DTC No. Index ......................................................... 8
Alphabetical Index .................................................. 12
PRECAUTIONS ........................................................ 16
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ................................................................ 16
Precautions for Procedures without Cowl Top Cover ... 16
On Board Diagnostic (OBD) System of Engine and
A/T, CVT ................................................................. 16
Precaution .............................................................. 17
PREPARATION ......................................................... 20
Special Service Tools ............................................. 20
Commercial Service Tools ...................................... 21
ENGINE CONTROL SYSTEM .................................. 22
System Diagram ..................................................... 22
Multiport Fuel Injection (MFI) System .................... 23
Electronic Ignition (EI) System ............................... 25
Fuel Cut Control (at No Load and High Engine
Speed) .................................................................... 26
AIR CONDITIONING CUT CONTROL ..................... 27
Input/Output Signal Chart ....................................... 27
System Description ................................................ 27
AUTOMATIC SPEED CONTROL DEVICE (ASCD) ... 28
System Description ................................................ 28
Component Description .......................................... 29
CAN COMMUNICATION .......................................... 30
System Description ................................................ 30
EVAPORATIVE EMISSION SYSTEM ....................... 31
Description ............................................................. 31
Component Inspection ........................................... 34
Removal and Installation ........................................ 35
How to Detect Fuel Vapor Leakage ....................... 35
ON BOARD REFUELING VAPOR RECOVERY
(ORVR) ...................................................................... 38
System Description ................................................ 38
Diagnostic Procedure ............................................. 39
Component Inspection ........................................... 42
POSITIVE CRANKCASE VENTILATION ................. 44Description .............................................................. 44
Component Inspection ............................................ 44
NVIS (NISSAN VEHICLE IMMOBILIZER SYSTEM-
NATS) ........................................................................ 46
Description .............................................................. 46
ON BOARD DIAGNOSTIC (OBD) SYSTEM ............ 47
Introduction ............................................................. 47
Two Trip Detection Logic ........................................ 47
Emission-related Diagnostic Information ................ 48
Malfunction Indicator Lamp (MIL) ........................... 61
OBD System Operation Chart ................................ 65
BASIC SERVICE PROCEDURE ............................... 70
Basic Inspection ..................................................... 70
Idle Speed and Ignition Timing Check .................... 75
Procedure After Replacing ECM ............................ 77
VIN Registration ..................................................... 77
Accelerator Pedal Released Position Learning ...... 77
Throttle Valve Closed Position Learning ................. 78
Idle Air Volume Learning ........................................ 78
Fuel Pressure Check .............................................. 81
TROUBLE DIAGNOSIS ............................................ 83
Trouble Diagnosis Introduction ............................... 83
DTC Inspection Priority Chart ................................. 89
Fail-Safe Chart ....................................................... 91
Symptom Matrix Chart ............................................ 92
Engine Control Component Parts Location ............ 96
Vacuum Hose Drawing .........................................102
Circuit Diagram .....................................................103
ECM Harness Connector Terminal Layout ...........105
ECM Terminals and Reference Value ...................105
CONSULT-II Function (ENGINE) ..........................113
Generic Scan Tool (GST) Function .......................126
CONSULT-II Reference Value in Data Monitor .....128
Major Sensor Reference Graph in Data Monitor
Mode .....................................................................131
TROUBLE DIAGNOSIS - SPECIFICATION VALUE .133
Description ............................................................133
Testing Condition ..................................................133
Inspection Procedure ............................................133
Diagnostic Procedure ...........................................134

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
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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

AIR CONDITIONING CUT CONTROL
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AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartUBS00PJV
*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 DescriptionUBS00PJW
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
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
EPS control unit
Power steering operation*
1
Wheel sensor
Vehicle speed*1

EC-44Revision: June 2006
POSITIVE CRANKCASE VENTILATION
2007 Versa
POSITIVE CRANKCASE VENTILATIONPFP:11810
DescriptionUBS00PK1
SYSTEM DESCRIPTION
This system returns blow-by gas to the intake manifold.
The positive crankcase ventilation (PCV) valve is provided to conduct crankcase blow-by gas to the intake
manifold. During partial throttle operation of the engine, the intake manifold sucks the blow-by gas through the
PCV valve. Normally, the capacity of the valve is sufficient to handle any blow-by and a small amount of venti-
lating air. The ventilating air is then drawn from the air inlet tubes into the crankcase. In this process the air
passes through the hose connecting air inlet tubes to rocker cover.
Under full-throttle condition, the manifold vacuum is insufficient to draw the blow-by flow through the valve.
The flow goes through the hose connection in the reverse direction.
On vehicles with an excessively high blow-by, the valve does not
meet the requirement. This is because some of the flow will go
through the hose connection to the air inlet tubes under all condi-
tions.
Component InspectionUBS00PK2
PCV (POSITIVE CRANKCASE VENTILATION) VALVE
With engine running at idle, remove PCV valve from rocker cover. A
properly working valve makes a hissing noise as air passes through
it. A strong vacuum should be felt immediately when a finger is
placed over valve inlet.
PBIB2962E
PBIB1588E
PBIB1589E

EC-48Revision: June 2006
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2007 Versa
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 InformationUBS00QBH
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 codeTe s t v a l u e /
Test limit
(GST only)TripMIL light-
ing upReference
page CONSULT-II
GST*
2ECM*3
CAN COMM CIRCUIT U1000
1000*4——1 (CVT)
1 (A/T)
2 (M/T)× (CVT)
× (A/T)
— (M/T)EC-151
CAN COMM CIRCUIT U1001
1001*4——2—EC-151
CONTROL UNIT(CAN) U1010 1010 — —1 (CVT)
1 (A/T)
2 (M/T)× (CVT)
× (A/T)
— (M/T)EC-154
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.P0000 0000———
Flashing*5EC-62
INT/V TIM CONT-B1 P0011 0011 — — 2×EC-156
A/F SEN1 HTR (B1) P0031 0031 —×2×EC-161
A/F SEN1 HTR (B1) P0032 0032 —×2×EC-161
HO2S2 HTR (B1) P0037 0037 —×2×EC-166
HO2S2 HTR (B1) P0038 0038 —×2×EC-166
INT/V TIM V/CIR-B1 P0075 0075 — — 2×EC-173
MAF SEN/CIRCUIT P0101 0101 — — 2×EC-178
MAF SEN/CIRCUIT P0102 0102 — — 1×EC-187
MAF SEN/CIRCUIT P0103 0103 — — 1×EC-187
IAT SEN/CIRCUIT P0112 0112 — — 2×EC-195
IAT SEN/CIRCUIT P0113 0113 — — 2×EC-195
ECT SEN/CIRC P0117 0117 — — 1×EC-200
ECT SEN/CIRC P0118 0118 — — 1×EC-200
TP SEN 2/CIRC P0122 0122 — — 1×EC-206
TP SEN 2/CIRC P0123 0123 — — 1×EC-206
ECT SENSOR P0125 0125 — — 1×EC-212
IAT SENSOR P0127 0127 — — 2×EC-215
THERMSTAT FNCTN P0128 0128 — — 2×EC-218
A/F SENSOR1 (B1) P0130 0130 —×2×EC-220
A/F SENSOR1 (B1) P0131 0131 —×2×EC-227
A/F SENSOR1 (B1) P0132 0132 —×2×EC-233
A/F SENSOR1 (B1) P0133 0133××2×EC-239
HO2S2 (B1) P0137 0137××2×EC-248
HO2S2 (B1) P0138 0138××2×EC-257
HO2S2 (B1) P0139 0139××2×EC-267
FUEL SYS-LEAN-B1 P0171 0171 — — 2×EC-276
FUEL SYS-RICH-B1 P0172 0172 — — 2×EC-284

EC-52Revision: June 2006
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2007 Versa
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, absolute throttle position, 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-116, "
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.
For example, the EGR malfunction (Priority: 2) was detected and the freeze frame data was stored in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st trip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or 1st
trip freeze frame data can be stored in the ECM). If freeze frame data is stored in the ECM memory and freeze
frame data with the same priority occurs later, the first (original) freeze frame data remains unchanged in the
ECM memory.
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM mem-
ory is erased. Procedures for clearing the ECM memory are described in EC-48, "
EMISSION-RELATED
DIAGNOSTIC INFORMATION ITEMS" .
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979.
As part of an enhanced emissions test for Inspection & Maintenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major emission systems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate “CMPLT” for each application system. Once set as “CMPLT”, the SRT status remains
“CMPLT” until the self-diagnosis memory is erased.
PBIB09 11 E
Priority Items
1Freeze frame data Misfire — DTC: P0300 - P0304
Fuel Injection System Function — DTC: P0171, P0172
2 Except the above items (Includes A/T or CVT related items)
3 1st trip freeze frame data