2003 NISSAN TEANA engine control

EC-24
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ENGINE CONTROL SYSTEM

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)BBS005BH
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed is over 1,800 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 be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under Multiport Fuel Injection (MFI) System, EC-21
.
Sensor Input Signal to ECM ECM function Actuator
Park/neutral position (PNP) switch 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
Wheel sensor Vehicle speed*

AIR CONDITIONING CUT CONTROL
EC-25
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AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartBBS005BI
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signal of engine speed and battery voltage.
SYSTEM DESCRIPTION
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
Air conditioner
cut controlAir conditioner relay Throttle position sensor Throttle position
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
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor
Vehicle speed*
1
Battery
Battery voltage*2

EVAPORATIVE EMISSION SYSTEM
EC-27
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EVAPORATIVE EMISSION SYSTEMPFP:14950
DescriptionBBS005BK
SYSTEM DESCRIPTION
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 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.
PBIB0491E

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-33
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ON BOARD DIAGNOSTIC (OBD) SYSTEMPFP:00028
IntroductionBBS005BP
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:
The above information can be checked using procedures listed in the table below.
×: Applicable —: Not applicable
*: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
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-59
.)
Two Trip Detection LogicBBS005BQ
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>
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 fail-safe mode (Refer to EC-59
.), the DTC is stored in the ECM
memory even in the 1st trip.
When there is an open circuit on MI circuit, the ECM can not warn the driver by lighting up MI when there is
trouble on engine control system. Therefore, when Electrical controlled throttle and part of the ECM related
diagnoses are continuously detected as NG for 5-trips, ECM warns the driver that engine control system has
trouble and MI circuit is open by means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MI circuit are detected and demands the
driver to repair the trouble.
Emission-related Diagnostic InformationBBS005BR
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS
×:Applicable —: Not applicable Emission-related diagnostic information
Diagnostic Trouble Code (DTC)
Freeze Frame data
1st Trip Diagnostic Trouble Code (1st Trip DTC)
1st Trip Freeze Frame data
DTC 1st trip DTC Freeze Frame data1st trip Freeze Frame
data
CONSULT-II×× × ×
ECM××*— —
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
Trip MIReference
page
CONSULT-II
ECM*2
CAN COMM CIRCUIT U1000
1000*32—EC-113
CAN COMM CIRCUIT U1001
1001*32—EC-113
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.P0000 0000—
Flashing*4EC-37
INT/V TIM CONT-B1 P0011 0011 2 —EC-116
MAF SEN/CIRCUIT P0102 0102 1×EC-124
MAF SEN/CIRCUIT P0103 0103 1×EC-124
ECT SEN/CIRC P0117 0117 2×EC-131
ECT SEN/CIRC P0118 0118 2×EC-131
TP SEN 2/CIRC P0122 0122 1×EC-136

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-37
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When there is an open circuit on MI circuit, the ECM can not warn the driver by lighting up MI when there is
trouble on engine control system.
Therefore, when Electrical controlled throttle and part of the ECM related diagnoses are continuously detected
as NG for 5-trips, ECM warns the driver that engine control system has trouble and MI circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MI circuit are detected and demands the
driver to repair the trouble.
MI Flashing without DTC
If the ECM is in Diagnostic Test Mode II, MI may flash when engine is running. In this case, check ECM diag-
nostic test mode. EC-37, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .
How to switch the diagnostic test (function) modes, and details of the above functions are described later, EC-
37 .
The following emission-related diagnostic information is cleared when the ECM memory is erased.

Diagnostic trouble codes

1st trip diagnostic trouble codes

Freeze frame data

1st trip freeze frame data

Others
HOW TO SWITCH DIAGNOSTIC TEST MODE
NOTE:

It is better to count the time accurately with a clock.

It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
Diagnostic Test
ModeKEY and ENG.
StatusFunction Explanation of Function
Mode I Ignition switch in
ON position
Engine stoppedBULB CHECK This function checks the MI bulb for damage (blown, open
circuit, etc.).
If the MI does not come on, check MI circuit.
Engine running MALFUNCTION
WARNINGThis is a usual driving condition. When a malfunction is
detected twice in two consecutive driving cycles (two trip
detection logic), the MI will light up to inform the driver that
a malfunction has been detected.
The following malfunctions will light up or blink the MI in
the 1st trip.

One trip detection diagnoses
Mode II Ignition switch in
ON position
Engine stoppedSELF-DIAGNOSTIC
RESULTSThis function allows DTCs and 1st trip DTCs to be read.
Engine running HEATED OXYGEN SENSOR 1
MONITORThis function allows the fuel mixture condition (lean or
rich), monitored by heated oxygen sensor 1, to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-39
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played, they may be either DTCs or 1st trip DTCs. DTC No. is same as that of 1st trip DTC. These unidentified
codes can be identified by using the CONSULT-II. A DTC will be used as an example for how to read a code.
A particular trouble code can be identified by the number of four-digit numeral flashes. The “zero” is indicated
by the number of ten flashes. The length of time the 1,000th-digit numeral flashes on and off is 1.2 seconds
consisting of an ON (0.6-second) - OFF (0.6-second) cycle.
The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later
numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-10, "
INDEX FOR DTC" )
How to Erase Diagnostic Test Mode II (Self-Diagnostic Results)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to EC-
37, "HOW TO SWITCH DIAGNOSTIC TEST MODE" .

If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.

Be careful not to erase the stored memory before starting trouble diagnoses.
DIAGNOSTIC TEST MODE II — HEATED OXYGEN SENSOR 1 MONITOR
In this mode, the MI displays the condition of the fuel mixture (lean or rich) which is monitored by the heated
oxygen sensor 1.
*: Maintains conditions just before switching to open loop.
To check the heated oxygen sensor 1 function, start engine in the Diagnostic Test Mode II and warm it up until
engine coolant temperature indicator points to the middle of the gauge.
Next run engine at about 2,000 rpm for about 2 minutes under no-load conditions. Then make sure that the MI
comes ON more than 5 times within 10 seconds with engine running at 2,000 rpm under no-load.
PBIA3905E
MI Fuel mixture condition in the exhaust gas Air fuel ratio feedback control condition
ON Lean
Closed loop system
OFF Rich
*Remains ON or OFF Any condition Open loop system

BASIC SERVICE PROCEDURE
EC-47
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3. Check ignition timing.
Procedure After Replacing ECMBBS005KR
When replacing ECM, the following procedure must be performed.
1. Perform initialization of NATS system and registration of all NATS ignition key IDs. Refer to BL-142, "
ECM
Re-Communicating Function" .
2. Perform EC-47, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-47, "
Throttle Valve Closed Position Learning" .
4. Perform EC-47, "
Idle Air Volume Learning" .
Accelerator Pedal Released Position LearningBBS005BV
DESCRIPTION
Accelerator Pedal Released Position Learning is an operation to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Closed Position LearningBBS005BW
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to learn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningBBS005BX
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:

Each time electric throttle control actuator or ECM is replaced.

Idle speed or ignition timing is out of specification.
PREPARATION
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)
PBIB2177E

EC-52
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TROUBLE DIAGNOSIS

TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionBBS005BZ
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the Work Flow on EC-53, "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Diagnostic Worksheet like the example
on EC-57, "
Worksheet Sample" should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
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