EC-488
< SYMPTOM DIAGNOSIS >[HR16DE]
ENGINE CONTROL SYSTEM SYMPTOMS
SYMPTOM DIAGNOSIS
ENGINE CONTROL SYSTEM SYMPTOMS
Symptom TableINFOID:0000000005930158
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit 11232 22 3 2EC-438
Fuel pressure regulator system 334444444 4 EC-499
Fuel injector circuit11232 22 2EC-434
Evaporative emission system 334444444 4 EC-79
Air Positive crankcase ventilation sys-
tem 334444444 41
EC-459
Incorrect idle speed adjustment 1 1 1 1 1EC-24
Electric throttle control actuator 112332222 2 2 EC-391EC-400
IgnitionIncorrect ignition timing adjustment33111 11
1EC-24
Ignition circuit 11222 22 2EC-444
Main power supply and ground circuit 22333 33 23 EC-123
Mass air flow sensor circuit
1
12 2
222 2 EC-150EC-150
Engine coolant temperature sensor circuit
333
EC-170EC-178
Air fuel ratio (A/F) sensor 1 circuit EC-185
EC-191
EC-196
EC-201
EC-420
Throttle position sensor circuit
22EC-174
EC-253
EC-376
EC-378
EC-411
Accelerator pedal position sensor circuit
3 2 1 EC-402EC-406
EC-415
Knock sensor circuit
23EC-263
Revision: May 2010 2011 Versa
ENGINE CONTROL SYSTEM SYMPTOMSEC-491
< SYMPTOM DIAGNOSIS > [HR16DE]
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1 - 6: The numbers refer to the order of inspection. Va l v e
mecha-
nism
Timing chain
55555 55 5 EM-49
Camshaft
EM-59
Intake valve timing controlEM-49
Intake valve
3EM-76
Exhaust valve
Exhaust Exhaust manifold/Tube/Muf- fler/Gasket 55555 55 5 EM-30
EX-4Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/ Oil filter/Oil gallery/Oil cooler 55555 55 5EM-39
EM-42
LU-7
LU-9
Oil level (Low)/Filthy oil
LU-7
Cooling Radiator/Hose/Radiator filler
cap
55555 55 45 CO-14
CO-14
Thermostat
5CO-23
Water pump CO-21
Water galleryCO-9
Cooling fan
5CO-19
Coolant level (Low)/Contami-
nated coolant
CO-9
NVIS (NISSAN Vehicle Immobilizer Sys-
tem — NATS)11
BL-255
SYMPTOM
Reference page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code A
A AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: May 2010
2011 Versa
EC-498
< PREPARATION >[HR16DE]
PREPARATION
Fuel filler cap adapter
i.e.: (MLR-8382)Checks fuel tank vacuum relief valve opening
pressure
Socket wrench Removes and installs engine coolant temperature
sensor
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12) Reconditions 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) Lubricates oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
Tool name
(Kent-Moore No.)
Description
S-NT815
S-NT705
AEM488
S-NT779
Revision: May 2010
2011 Versa
EC-516
< SERVICE INFORMATION >[MR18DE]
PREPARATION
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.
Tool number
(Kent-Moore No.)
Tool name
Description
S-NT815
S-NT705
AEM488
S-NT779
Revision: May 2010
2011 Versa
EC-518
< SERVICE INFORMATION >[MR18DE]
ENGINE CONTROL SYSTEM
*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). T he 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 t he crankshaft position sensor (POS), camshaft position
sensor (PHASE) and the ma ss air flow sensor.
VARIOUS FUEL INJECTION I NCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.
• 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 high engine speed operation
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
Sensor Input Signal to ECMECM functionActuator
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) signal Gear position
Battery Battery voltage*
3
Knock sensorEngine 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
ABS actuator and electric unit (control unit)
Vehicle speed*2
Combination meter
PBIB3020E
Revision: May 2010 2011 Versa
ENGINE CONTROL SYSTEMEC-519
< SERVICE INFORMATION > [MR18DE]
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The mixture ratio feedback system provides the best air/
fuel mixture ratio for drivability and emission control.
The three way catalyst (manifold) can then better r educe 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-704
. 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 th ree 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 tr ansmitted 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 bas ic 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 co mpared 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 compensati on used to maintain the mixture ratio at its theoretical
value. The signal from air fuel ratio (A/F) sensor 1 i ndicates 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 ca rried 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 cycl e 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.
SEF337W
Revision: May 2010 2011 Versa
EC-520
< SERVICE INFORMATION >[MR18DE]
ENGINE CONTROL SYSTEM
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) SystemINFOID:0000000006341699
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 si gnals are transmitted to the power transistor.
During the following conditions, the ignition timing is re vised by the ECM according to the other data stored in
the ECM.
• At starting
• During warm-up
• At idle
• At low battery voltage
• 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)INFOID:0000000006341700
INPUT/OUTPUT SIGNAL CHART
Sensor Input Signal to ECMECM functionActuator
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 sensorEngine knocking
Park/neutral position (PNP) signal Gear position
ABS actuator and electric unit (control unit)
Vehicle speed*
1Combination meter
Sensor Input Signal to ECMECM functionActuator
Park/neutral position (PNP) signal Neutral position
Fuel cut control 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
ABS actuator and electric unit (control unit) Vehicle speed*
Combination meter
Revision: May 2010 2011 Versa
EC-522
< SERVICE INFORMATION >[MR18DE]
AIR CONDITIONING CUT CONTROL
AIR CONDITIONING CUT CONTROL
Input/Output Signal ChartINFOID:0000000006341701
*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 DescriptionINFOID:0000000006341702
This system improves engine operati
on 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 temperat ure 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 ECMECM functionActuator
Air conditioner switch Air conditioner ON signal*
1
Air conditioner
cut controlAir conditio
ner 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 sensorRefrigerant pressure
EPS control unit Power steering operation*
1
ABS actuator and electric unit (control unit)
Vehicle speed*1
Combination meter
Revision: May 2010 2011 Versa