2005 NISSAN X-TRAIL OBD port

ENGINE CONTROL SYSTEM
EC-37
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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 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 or operation of the engine at excessively high speeds.
Electronic Ignition (EI) SystemEBS010LA
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
The ignition timing is controlled by the ECM to maintain the best air-
fuel ratio for every running condition of the engine. The ignition tim-
ing data is stored in the ECM. This data forms the map shown.
The ECM receives information such as the injection pulse width and
camshaft position sensor signal. Computing this information, ignition
signals are transmitted to the power transistor.
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
SEF337W
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS)
Engine speed*
2
piston position
Ignition
timing con-
trolPower 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
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor*1Vehicle speed
SEF742M

EC-38
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ENGINE CONTROL SYSTEM


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.
Air Conditioning Cut ControlEBS010LB
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
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.
Fuel Cut Control (at No Load and High Engine Speed)EBS010LC
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 EC-35, "
Multiport Fuel Injection (MFI) System" .
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 valve opening angle
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
Power steering pressure sensor Power steering operation
Wheel sensor*
1Vehicle speed
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

BASIC SERVICE PROCEDURE
EC-47
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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 LearningEBS010LG
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 LearningEBS010LH
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)

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.

Steering wheel: Neutral (Straight-ahead position)

Vehicle speed: Stopped

Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until “FLUID TEMP SE” in “DATA MONITOR” mode of “A/
T” system indicates less than 0.9V.
For A/T models without CONSULT-II and M/T models, drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-46, "Accelerator Pedal Released Position Learning" .
2. Perform EC-47, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
SEF217Z

BASIC SERVICE PROCEDURE
EC-49
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12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.
13. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried
out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCE-
DURE below.
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1.Check that throttle valve is fully closed.
2.Check PCV valve operation.
3.Check that downstream of throttle valve is free from air leakage.
4.When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the incident.
It is useful to perform EC-120, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
5.If any of the following conditions occur after the engine has started, eliminate the cause of the
incident and perform Idle Air Volume Learning all over again:

Engine stalls.

Erroneous idle.
Fuel Pressure CheckEBS010LI
FUEL PRESSURE RELEASE
With CONSULT-II
1. Turn ignition switch ON.
2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT”
mode with CONSULT-II.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch OFF.
Without CONSULT-II
1. Remove fuel pump fuse located in fuse box.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch OFF.
5. Reinstall fuel pump fuse after servicing fuel system.
FUEL PRESSURE CHECK
CAUTION:
Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
ITEM SPECIFICATION
Idle speed QR20DE with M/T models: 650 ± 50 rpm (in Neutral position)
Except above: 700 ± 50 rpm [in P or N (A/T), Neutral (M/T) position]
Ignition timing M/T: 15 ± 5° BTDC (in Neutral position)
A/T: 15 ± 5° BTDC (in P or N position)
SEF214Y
PBIB0508E

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-57
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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.
Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's
normal driving pattern; the SRT will indicate “INCMP” for these items.
NOTE:
The SRT will also indicate “INCMP” if the self-diagnosis memory is erased for any reason or if the ECM mem-
ory power supply is interrupted for several hours.
If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indicates “INCMP” for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MI is “ON” during the state emissions inspection, the vehicle is also returned to the customer untested even
though the SRT indicates “CMPLT” for all test items. Therefore, it is important to check SRT (“CMPLT”) and
DTC (No DTCs) before the inspection.
SRT Item
The table below shows required self-diagnostic items to set the SRT to “CMPLT”.
*: If completion of several SRTs is required, perform driving patterns (DTC confirmation procedure), one by one based on the priority for
models with CONSULT-II.
SRT Set Timing
SRT is set as “CMPLT” after self-diagnosis has been performed one or more times. Completion of SRT is
done regardless of whether the result is OK or NG. The set timing is different between OK and NG results and
is shown in the table below.
SRT item
(CONSULT-II
indication)Performance
Priority*Required self-diagnostic items to set the SRT to “CMPLT” Corresponding DTC No.
CATALYST 2 Three way catalyst function P0420
HO2S 1 Heated oxygen sensor 1 P0133
Heated oxygen sensor 1 P1143
Heated oxygen sensor 1 P1144
Heated oxygen sensor 2 P0139
Heated oxygen sensor 2 P1146
Heated oxygen sensor 2 P1147
HO2S HTR 1 Heated oxygen sensor 1 heater P0031, P0032
Heated oxygen sensor 2 heater P0037, P0038
Self-diagnosis resultExample
DiagnosisIgnition cycle
← ON → OFF ← ON → OFF ← ON → OFF ← ON →
All OK Case 1 P0400 OK (1) — (1) OK (2) — (2)
P0402 OK (1) — (1) — (1) OK (2)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “CMPLT” “CMPLT” “CMPLT” “CMPLT”
Case 2 P0400 OK (1) — (1) — (1) — (1)
P0402 — (0) — (0) OK (1) — (1)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “INCMP” “INCMP” “CMPLT” “CMPLT”

TROUBLE DIAGNOSIS
EC-73
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TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionEBS010LP
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 GST) or a circuit tester connected should
be performed. Follow EC-74, "
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-76, "
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
SEF234G

EC-76
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TROUBLE DIAGNOSIS

DIAGNOSTIC WORKSHEET
Description
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about a incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MI to come on steady or blink and
DTC to be detected. Examples:

Vehicle ran out of fuel, which caused the engine to misfire.
Worksheet Sample
SEF907L
MTBL0017

TROUBLE DIAGNOSIS
EC-103
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*1: For QR25DE engine models
CONSULT-II Function (ENGINE)EBS010LY
FUNCTION
*: 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

System readiness test (SRT) codes

Test valuesDiagnostic test mode Function
Work supportThis mode enables a technician to adjust some devices faster and more accurately by following the
indications on the CONSULT-II unit.
Self-diagnostic resultsSelf-diagnostic results such as 1st trip DTC, DTCs and 1st trip freeze frame data or freeze frame data
can be read and erased quickly.*
Data monitor Input/Output data in the ECM can be read.
Data monitor (SPEC)Input/Output of the specification for Basic fuel schedule, AFM, A/F feedback control value and the
other data monitor items can be read.
CAN diagnostic support
monitorThe results of transmit/receive diagnosis of CAN communication can be read.
Active testDiagnostic Test Mode in which CONSULT-II drives some actuators apart from the ECMs and also
shifts some parameters in a specified range.
Function test This mode is used to inform customers when their vehicle condition requires periodic maintenance.
DTC & SRT confirmation The status of system monitoring tests and the self-diagnosis status/result can be confirmed.
ECM part number ECM part number can be read.