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Nissan Almera Tino V10 (2001 year). Manual - part 63

Multiport Fuel Injection (MFI) System

DESCRIPTION

NLEC1342

Input/Output Signal Chart

NLEC1342S01

Sensor

Input Signal to ECM

ECM func-

tion

Actuator

Camshaft position sensor

Engine speed and piston position

Fuel injec-
tion & mix-
ture ratio
control

Injector

Mass air flow sensor

Amount of intake air

Engine coolant temperature sensor

Engine coolant temperature

Heated oxygen sensor 1 (front)

Density of oxygen in exhaust gas

Throttle position sensor

Throttle position
Throttle valve idle position

PNP switch

Gear position

Vehicle speed sensor

Vehicle speed

Ignition switch

Start signal

Air conditioner switch

Air conditioner operation

Knock sensor

Engine knocking condition

Electrical load

Electrical load signal

Battery

Battery voltage

Power steering oil pressure switch

Power steering operation

Heated oxygen sensor 2 (rear)*

Density of oxygen in exhaust gas

* Under normal conditions, this sensor is not for engine control operation.

Basic Multiport Fuel Injection System

NLEC1342S02

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 both the camshaft position sensor and the mass air
flow sensor.

Various Fuel Injection Increase/Decrease Compensation

NLEC1342S03

In addition, the amount of fuel injected is compensated to improve engine performance under various oper-
ating conditions as listed below.
<Fuel increase>

During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from “N” to “D”

High-load, high-speed operation

During deceleration

During high engine speed operation

Extremely high engine coolant temperature

ENGINE AND EMISSION BASIC CONTROL SYSTEM

DESCRIPTION

SR20DE

Multiport Fuel Injection (MFI) System

EC-569

Mixture Ratio Feedback Control (Closed loop control)

NLEC1342S04

SEF336WA

The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission con-
trol. The three way catalyst can then better reduce CO, HC and NOx emissions. This system uses a heated
oxygen sensor 1 (front) in the exhaust manifold to monitor if the engine operation is rich or lean. The ECM
adjusts the injection pulse width according to the sensor voltage signal. For more information about the heated
oxygen sensor 1 (front), refer to EC-709. 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 (rear) is located downstream of the three way catalyst. Even if the switching char-
acteristics of the heated oxygen sensor 1 (front) shift, the air-fuel ratio is controlled to stoichiometric by the
signal from the heated oxygen sensor 2 (rear).

Open Loop Control

NLEC1342S05

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 heated oxygen sensor 1 (front) or its circuit

Insufficient activation of heated oxygen sensor 1 (front) at low engine coolant temperature

High engine coolant temperature

During warm-up

When starting the engine

Mixture Ratio Self-learning Control

NLEC1342S06

The mixture ratio feedback control system monitors the mixture ratio signal transmitted from the heated oxy-
gen sensor 1 (front). 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 con-
trolled as originally designed. Both manufacturing differences (i.e., mass air flow sensor hot film) and charac-
teristic changes during operation (i.e., 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 the heated oxygen sensor 1 (front) indicates whether the mixture ratio is RICH or LEAN
compared 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.

ENGINE AND EMISSION BASIC CONTROL SYSTEM

DESCRIPTION

SR20DE

Multiport Fuel Injection (MFI) System (Cont’d)

EC-570

Fuel Injection Timing

NLEC1342S07

SEF337W

Two types of systems are used.
Sequential Multiport Fuel Injection System

NLEC1342S0701

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

NLEC1342S0702

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 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

NLEC1342S08

Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.

Electronic Ignition (EI) System

DESCRIPTION

NLEC1343

Input/Output Signal Chart

NLEC1343S01

Sensor

Input Signal to ECM

ECM func-

tion

Actuator

Camshaft position sensor

Engine speed and piston position

Ignition tim-
ing control

Power transistor

Mass air flow sensor

Amount of intake air

Engine coolant temperature sensor

Engine coolant temperature

Throttle position sensor

Throttle position
Throttle valve idle position

Vehicle speed sensor

Vehicle speed

Ignition switch

Start signal

Knock sensor

Engine knocking

PNP switch

Gear position

Battery

Battery voltage

ENGINE AND EMISSION BASIC CONTROL SYSTEM

DESCRIPTION

SR20DE

Multiport Fuel Injection (MFI) System (Cont’d)

EC-571

System Description

NLEC1343S02

SEF742M

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. This data forms the map shown above.
The ECM receives information such as the injection pulse width, crankshaft position sensor signal and cam-
shaft position sensor signal. Computing this information, ignition signals are transmitted to the power transis-
tor.
e.g.,

N: 1,800 rpm, Tp: 1.50 msec

A°BTDC

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

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.

Air Conditioning Cut Control

DESCRIPTION

NLEC1344

Input/Output Signal Chart

NLEC1344S01

Sensor

Input Signal to ECM

ECM func-

tion

Actuator

Air conditioner switch

Air conditioner “ON” signal

Air condi-
tioner cut
control

Air conditioner relay

PNP switch

Neutral position

Throttle position sensor

Throttle valve opening angle

Camshaft position sensor

Engine speed

Engine coolant temperature sensor

Engine coolant temperature

Ignition switch

Start signal

Refrigerant pressure sensor

Refrigerant pressure

Vehicle speed sensor

Vehicle speed

Power steering oil pressure switch

Power steering operation

System Description

NLEC1344S02

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.

ENGINE AND EMISSION BASIC CONTROL SYSTEM

DESCRIPTION

SR20DE

Electronic Ignition (EI) System (Cont’d)

EC-572

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 the refrigerant pressure is excessively high or low.

Fuel Cut Control (at no load & high engine
speed)

DESCRIPTION

NLEC1345

Input/Output Signal Chart

NLEC1345S01

Sensor

Input Signal to ECM

ECM func-

tion

Actuator

Vehicle speed sensor

Vehicle speed

Fuel cut
control

Injectors

PNP switch

Neutral position

Throttle position sensor

Throttle position

Engine coolant temperature sensor

Engine coolant temperature

Camshaft position sensor

Engine speed

If the engine speed is above 3,950 rpm with no load, (for example, in Neutral and engine speed over 4,000
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,150 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under “Multiport Fuel Injection (MFI) System”,
EC-569.

Evaporative Emission System

DESCRIPTION

NLEC1346

SEF916WA

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

ENGINE AND EMISSION BASIC CONTROL SYSTEM

DESCRIPTION

SR20DE

Air Conditioning Cut Control (Cont’d)

EC-573

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.

SEF917W

INSPECTION

NLEC1347

EVAP Canister

NLEC1347S01

Check EVAP canister as follows:
1.

Block port B. Orally blow air through port A. Check that air
flows freely through port C with check valve resistance.

Block port A. Orally blow air through port B. Check that air
flows freely through port C.

SEF918W

SEF943S

Fuel Tank Vacuum Relief Valve (Built into fuel filler cap)

NLEC1347S02

Wipe clean valve housing.

Check valve opening pressure and vacuum.

Pressure:

15.3 - 20.0 kPa (0.15 - 0.20 bar, 0.156 - 0.204 kg/cm

2.22 - 2.90 psi)

Vacuum:

−6.0 to −3.4 kPa (−0.060 to −0.034 bar, −0.061 to
−0.035 kg/cm

, −0.87 to −0.50 psi)

If out of specification, replace fuel filler cap as an assembly.

Evaporative Emission (EVAP) Canister Purge Volume
Control Solenoid Valve

NLEC1347S03

Refer to EC-857.

Checking EVAP Vapour Lines

NLEC1347S05

Visually inspect vapor lines for leaks, cracks, damage, loose
connections, chafing and deterioration.

Inspect vacuum relief valve of fuel tank filler cap for clogging,
sticking, etc. Refer to next page.

ENGINE AND EMISSION BASIC CONTROL SYSTEM

DESCRIPTION

SR20DE

Evaporative Emission System (Cont’d)

EC-574

EVAPORATIVE EMISSION LINE DRAWING

=NLEC1348

NOTE:
Do not use soapy water or any type of solvent while installing vacuum hoses or purge hoses.

SEF767Z

ENGINE AND EMISSION BASIC CONTROL SYSTEM

DESCRIPTION

SR20DE

Evaporative Emission System (Cont’d)

EC-575

Positive Crankcase Ventilation

DESCRIPTION

NLEC1349

SEF833X

This system returns blow-by gas to the intake collector.
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 ventilating air.
The ventilating air is then drawn from the air duct 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 intake collector under all conditions.

SEC137A

INSPECTION

NLEC1350

PCV (Positive Crankcase Ventilation) Valve

NLEC1350S01

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 fin-
ger is placed over the valve inlet.

ET277

Ventilation Hose

NLEC1350S02

Check hoses and hose connections for leaks.

Disconnect all hoses and clean with compressed air. If any
hose cannot be freed of obstructions, replace.

ENGINE AND EMISSION BASIC CONTROL SYSTEM

DESCRIPTION

SR20DE

Positive Crankcase Ventilation

EC-576

SEF094Y

SEF214Y

Fuel Pressure Release

NLEC1351

Before disconnecting fuel line, release fuel pressure from fuel
line to eliminate danger.

WITH CONSULT-II

NLEC1351S01

Start engine.

Perform “FUEL PRESSURE RELEASE” in “WORK SUP-
PORT” mode with CONSULT-II.

After engine stalls, crank it two or three times to release all fuel
pressure.

Turn ignition switch OFF.

JEF086Y

WITHOUT CONSULT-II

NLEC1351S02

Remove fuse for fuel pump. Refer to fuse block cover for fuse
location.

Start engine.

After engine stalls, crank it two or three times to release all fuel
pressure.

Turn ignition switch OFF and reconnect fuel pump fuse.

SEF775Z

Fuel Pressure Check

NLEC1352

When reconnecting fuel line, always use new clamps.

Make sure that clamp screw does not contact adjacent
parts.

Use a torque driver to tighten clamps.

Use Pressure Gauge to check fuel pressure.

Do not perform fuel pressure check with system operat-
ing. Fuel pressure gauge may indicate false readings.

Release fuel pressure to zero.

Disconnect fuel hose from fuel feed tube (engine side).

Install pressure gauge between fuel hose and fuel feed tube.

Start engine and check for fuel leakage.

Read the indication of fuel pressure gauge.

At idle speed:

With vacuum hose connected

Approximately 235 kPa (2.35 bar, 2.4 kg/cm

, 34

psi)

With vacuum hose disconnected

Approximately 294 kPa (2.94 bar, 3.0 kg/cm

, 43

psi)

BASIC SERVICE PROCEDURE

SR20DE

Fuel Pressure Release

EC-577

If results are unsatisfactory, perform Fuel Pressure Regulator
Check, EC-578.

SEF718B

Fuel Pressure Regulator Check

NLEC1353

Stop engine and disconnect fuel pressure regulator vacuum
hose from intake manifold collector.

Plug intake manifold collector with a rubber cap.

Connect variable vacuum source to fuel pressure regulator.

Start engine and read indication of fuel pressure gauge as
vacuum is changed.

Fuel pressure should decrease as vacuum increases. If results
are unsatisfactory, replace fuel pressure regulator.

Injector

REMOVAL AND INSTALLATION

NLEC1746

SEF324Z

Release fuel pressure to zero.

Remove accelerator wire bracket.

Remove EVAP canister purge volume control solenoid valve
and the bracket.

BASIC SERVICE PROCEDURE

SR20DE

Fuel Pressure Regulator Check

EC-578

Remove ventilation hose.

Disconnect injector harness connectors.

Disconnect fuel pressure regulator vacuum hose from intake
manifold collector.

Disconnect fuel hoses from fuel tube assembly.

Remove injectors with fuel tube assembly.

SEF703X

Expand and remove clips securing fuel injectors.

10. Extract fuel injectors straight from fuel tubes.

Be careful not to damage injector nozzles during removal.

Do not bump or drop fuel injectors.

11. Carefully install O-rings, including the one used with the pres-

sure regulator.

Lubricate O-rings with a smear of engine oil.

Be careful not to damage O-rings with service tools or
finger nails or clips. Do not expand or twist O-rings.

Discard old clips; replace with new ones.

12. Position clips in grooves on fuel injectors.

Make sure that protrusions of fuel injectors are aligned
with cutouts of clips after installation.

13. Align protrusions of fuel tubes with those of fuel injectors.
14. After properly inserting fuel injectors, check to make sure that

fuel tube protrusions are engaged with those of fuel injectors,
and that flanges of fuel tubes are engaged with clips.

SEF828X

15. Tighten fuel tube assembly mounting nuts in two stages.

: Tightening torque N·m (kg-m, ft-lb)

1st stage:

9.4 - 10.7 (0.95 - 1.1, 6.9 - 7.9)

2nd stage:

21 - 26 (2.1 - 2.7, 16 - 19)

16. Install all removed parts in the reverse order of removal.

CAUTION:

After properly connecting fuel tube assembly to injector and
fuel hose, check connection for fuel leakage.

SEF910X

THROTTLE OPENER (WHERE FITTED)

NLEC1747

Inspection

NLEC1747S01

Start engine and let it idle.

Confirm the amount of the rod moves “L” more than 3.0 mm
(0.118 in), the throttle drum becomes free from the rod of the
throttle opener.
If NG, go to next step.
If OK, inspection is complete.

BASIC SERVICE PROCEDURE

SR20DE

Injector (Cont’d)

EC-579

SEF109L

SEF368U

Turn ignition switch “OFF”.

Check vacuum source to throttle opener.

Check vacuum hose for disconnection or improper connection.

Remove vacuum hose connected to throttle opener.

Attach a vacuum gauge to vacuum hose, which is discon-
nected.

Start engine and let it idle.

Make sure that the vacuum is more than −40.0 kPa (−400
mbar, −300 mmHg, −11.81 inHg).

Remove the vacuum gauge.
If NG, go to next step.
If OK, go to step 7.

Check vacuum hose for clogging and cracks.
If NG, replace or clean vacuum hose.
If OK, go to next step.

Blow air into the throttle chamber and make sure air flows
freely.
If NG, replace or clean throttle chamber.
If OK, go to next step.

SEF793W

Check throttle opener.

Connect suitable vacuum hose to vacuum pump as shown at
left.

Apply vacuum [more than −40.0 kPa (−400 mbar, −300 mmHg,
−11.81 inHg)] until the throttle drum becomes free from the rod
of the throttle opener.

Confirm the amount of the rod moves more than 3.0 mm (0.118
in), and also the throttle drum becomes free from the rod of the
throttle opener.
If NG, go to next step.

Check visually for cracking and/or distortion of throttle opener
and rod.
If NG, replace throttle opener.
If OK, install the vacuum hose and repeat from step 1 to 2.

BASIC SERVICE PROCEDURE

SR20DE

Injector (Cont’d)

EC-580

SEF217Z

SEF454Y

SEF455Y

Idle Air Volume Learning

NLEC1358

DESCRIPTION

NLEC1358S01

“Idle Air Volume Learning” is an operation to learn the idle air vol-
ume that keeps each engine within the specific range. It must be
performed under any of the following conditions:

Each time IACV-AAC valve, throttle body or ECM is replaced.

Idle speed or ignition timing is out of specification.

PRE-CONDITIONING

NLEC1358S02

Before performing “Idle Air Volume Learning”, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.

Battery voltage: More than 12.9V (At idle)

Engine coolant temperature: 70 - 95°C (158 - 203°F)

PNP switch: ON

Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)

On vehicles equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.

Cooling fan motor: Not operating

Steering wheel: Neutral (Straight-ahead position)

Vehicle speed: Stopped

Transmission: Warmed-up
For models with CONSULT-II, drive vehicle until “FLUID TEMP
SE” in “DATA MONITOR” mode of “CVT” indicates less than
0.9V.
For models without CONSULT-II, drive vehicle for 10 minutes.

OPERATION PROCEDURE

NLEC1358S03

With CONSULT-II

NLEC1358S0301

Turn ignition switch “ON” and wait at least 1 second.

Turn ignition switch “OFF” and wait at least 10 seconds.

Start engine and warm it up to normal operating temperature.

Check that all items listed under the topic “PRE-CONDITION-
ING” (previously mentioned) are in good order.

Turn ignition switch “OFF” and wait at least 10 seconds.

Start the engine and let it idle for at least 15 seconds.

Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.

Touch “START” and wait 15 seconds.

Make sure that “CMPLT” is displayed on CONSULT-II screen.
If “INCMP” is displayed, “Idle Air Volume Learning” will not be
carried out successfully. In this case, find the cause of the
problem by referring to the NOTE below.

10. Rev up the engine two or three times. Make sure that idle

speed and ignition timing are within specifications.

ITEM

SPECIFICATION

Idle speed

750

50 rpm (in “P” or “N” position)

Ignition timing

2° BTDC (in “P” or “N” position)

BASIC SERVICE PROCEDURE

SR20DE

Injector (Cont’d)

EC-581

SEF770Z

Without CONSULT-II

NLEC1358S0302

Turn ignition switch “ON” and wait at least 1 second.

Turn ignition switch “OFF” and wait at least 10 seconds.

Start engine and warm it up to normal operating temperature.

Check that all items listed under the topic “PRE-CONDITION-
ING” (previously mentioned) are in good order.

Turn ignition switch “OFF” and wait at least 10 seconds.

Start the engine and let it idle for at least 15 seconds.

Disconnect throttle position sensor harness connector (brown),
then reconnect it within 5 seconds.

Wait 15 seconds.

Make sure that idle speed is within specifications. If not, the
result will be incomplete. In this case, find the cause of the
problem by referring to the NOTE below.

10. Rev up the engine two or three times. Make sure that idle

speed and ignition timing are within specifications.

ITEM

SPECIFICATION

Idle speed

750

50 rpm (in “P” or “N” position)

Ignition timing

2° BTDC (in “P” or “N” position)

NOTE:
If idle air volume learning cannot be performed successfully,
proceed as follows:
1)

Check that throttle valve is fully closed.

Check that downstream of throttle valve is free from air
leakage.

Adjust closed throttle position switch and reset memory.
(Refer to Basic Inspection, EC-623.)

When the above three items check out OK, engine com-
ponent parts and their installation condition are question-
able. Check and eliminate the cause of the problem.

If any of the following conditions occur after the engine
has started, eliminate the cause of the problem and per-
form “Idle air volume learning” all over again:

Engine stalls.

Erroneous idle.

Blown fuses related to the IACV-AAC valve system.

BASIC SERVICE PROCEDURE

SR20DE

Idle Air Volume Learning (Cont’d)

EC-582

Introduction

NLEC1359

MODELS WITH EURO-OBD SYSTEM

NLEC1359S01

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:

Diagnostic Trouble Code (DTC)

Mode 3 of ISO 15031-5

Freeze Frame data

Mode 2 of ISO 15031-5

System Readiness Test (SRT) code

Mode 1 of ISO 15031-5

1st Trip Diagnostic Trouble Code (1st Trip DTC)

Mode 7 of ISO 15031-5

1st Trip Freeze Frame data

Test values and Test limits

Mode 6 of ISO 15031-5

Calibration ID

Mode 9 of ISO 15031-5

The above information can be checked using procedures listed in the table below.

X: Applicable

—: Not applicable

DTC

1st trip DTC

Freeze Frame

data

1st trip Freeze

Frame data

SRT code

Test value

ECM*3

X*1

—

CONSULT-II

—

GST

X*2

—

*1: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
*2: 1st trip DTCs for self-diagnoses concerning SRT items cannot be shown on the GST display.
*3: In diagnostic test mode II (Self-diagnostic results), DTC is displayed on MI. DTC uses a set of four digit numbers.

The malfunction indicator (MI) 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-647.)

MODELS WITHOUT EURO-OBD SYSTEM

NLEC1359S02

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:

Diagnostic Trouble Code (DTC)

Freeze Frame data

1st Trip Diagnostic Trouble Code (1st Trip DTC)

1st Trip Freeze Frame data

The above information can be checked using procedures listed in the table below.

X: Applicable

—: Not applicable

DTC

1st trip DTC

Freeze Frame data

1st trip Freeze Frame

data

CONSULT-II

ECM*1

X*2

—

*1: In diagnostic test mode II (Self-diagnostic results), (1st trip) DTC is displayed on the MI by a set of four digit numbers.
*2: When the DTC and the 1st trip DTC appear on the display simultaneously, it is difficult to clearly distinguish one from the other.

Two Trip Detection Logic

NLEC1360

MODELS WITH EURO-OBD SYSTEM

NLEC1360S01

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 MI 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 MI lights up. The MI lights up at the same time when the DTC is stored <2nd
trip>.

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION

SR20DE

Introduction

EC-583

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 MI, and store
DTC and Freeze Frame data, even in the 1st trip, as shown below.

X: Applicable

—: Not applicable

Items

DTC

1st trip DTC

1st trip

2nd trip

1st trip

displaying

2nd trip

displaying

1st trip

displaying

2nd trip

displaying

Blinking

Lighting

Blinking

Lighting

Misfire (Possible three way
catalyst damage)
— DTC: P0300 - P0304 is
being detected

—

Misfire (Possible three way
catalyst damage)
— DTC: P0300 - P0304 is
being detected

—

Fail-safe items (Refer to
EC-647.)

—

X*1

—

X*1

—

Except above

—

*1: Except “ECM”.

MODELS WITHOUT EURO-OBD SYSTEM

NLEC1360S02

When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in
the ECM memory. <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. <2nd trip> The “trip” in the “Two Trip Detection Logic” means a driving mode in which
self-diagnosis is performed during vehicle operation. When the ECM enters the fail-safe mode (Refer to
EC-647), the DTC is stored in the ECM memory even in the 1st trip.

Emission-related Diagnostic Information

NLEC1361

MODELS WITH EURO-OBD SYSTEM

NLEC1361S01

DTC and 1st Trip DTC

NLEC1361S0101

The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, the 1st trip
DTC will not be displayed. If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM
memory. The MI will not light up (two trip detection logic). If the same malfunction is not detected in the 2nd
trip (meeting the required driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same mal-
function is detected in the 2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MI
lights up. In other words, the DTC is stored in the ECM memory and the MI lights up when the same malfunc-
tion occurs in two consecutive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed
between the 1st and 2nd trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or
light up the MI during the 1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in “How to Erase
Emission-related Diagnostic Information”. Refer to EC-594.
For malfunctions in which 1st trip DTCs are displayed, refer to EC-592. These items are required by legal
regulations to continuously monitor the system/component. In addition, the items monitored non-continuously
are also displayed on CONSULT-II.
1st trip DTC is specified in Mode 7 of ISO 15031-5. 1st trip DTC detection occurs without lighting up the MI
and therefore does not warn the driver of a problem. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in “Work Flow” procedure Step II, refer to page EC-621. Then perform “DTC Confirmation
Procedure” or “Overall Function Check” to try to duplicate the problem. If the malfunction is duplicated, the
item requires repair.
How to read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.

With CONSULT-II/

With GST

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION

SR20DE

Two Trip Detection Logic (Cont’d)

EC-584

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