2003 NISSAN X-TRAIL ECU

EC-64
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ON BOARD DIAGNOSTIC (OBD) SYSTEM

2. Perform AT- 4 3 , "HOW TO ERASE DTC (WITH GST)" . (The DTC in the TCM will be erased.)
3. Select MODE 4 with GST (Generic Scan Tool).
No Tools
NOTE:
If the DTC is not for A/T related items (see EC-19
), skip step 2.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once.
Wait at least 10 seconds and then turn it ON (engine stopped) again.
2. Perform AT- 4 3 , "
HOW TO ERASE DTC (NO TOOLS)" . (The DTC in TCM will be erased.)
3. Change the diagnostic test mode from Mode II to Mode I by depressing the accelerator pedal. Refer to
EC-66, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .

If the battery is disconnected, the emission-related diagnostic information will be lost within 24
hours.

The following data are 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 values
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
NATS (Nissan Anti-theft System)EBS010LM

If the security indicator lights up with the ignition switch in
the ON position or “NATS MALFUNCTION” is displayed on
“SELF-DIAG RESULTS” screen, perform self-diagnostic
results mode with CONSULT-II using NATS program card.
Refer to BL-108, "
NATS (NISSAN ANTI-THEFT SYSTEM)" .

Confirm no self-diagnostic results of NATS is displayed
before touching “ERASE” in “SELF-DIAG RESULTS” mode
with CONSULT-II.

When replacing ECM, initialization of NATS system and reg-
istration of all NATS ignition key IDs must be carried out
with CONSULT-II using NATS program card.
Therefore, be sure to receive all keys from vehicle owner.
Regarding the procedures of NATS initialization and all NATS ignition key ID registration, refer to
CONSULT-II Operation Manual, NATS.
Malfunction Indicator (MI)EBS010LN
DESCRIPTION
The MI is located on the instrument panel.
1. The MI will light up when the ignition switch is turned ON without
the engine running. This is a bulb check.
If the MI does not light up, refer to DI-33, "
WARNING LAMPS"
or see EC-469 .
2. When the engine is started, the MI should go off.
If the MI remains on, the on board diagnostic system has
detected an engine system malfunction.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following four functions.
SEF515Y
SAT652J

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-65
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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 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-66, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .
How to switch the diagnostic test (function) modes, and details of the above functions are described later, EC-
66 .
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 values
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.

Misfire (Possible three way catalyst damage)

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-67
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codes can be identified by using the CONSULT-II or GST. 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-19, "
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-
66, "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.
OBD System Operation ChartEBS010LO
RELATIONSHIP BETWEEN MI, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMS

When a malfunction is detected for the first time, the 1st trip DTC and the 1st trip freeze frame data are
stored in the ECM memory.

When the same malfunction is detected in two consecutive trips, the DTC and the freeze frame data are
stored in the ECM memory, and the MI will come on. For details, refer to EC-51, "
Tw o Tr i p D e t e c t i o n
Logic" .
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

EC-68
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ON BOARD DIAGNOSTIC (OBD) SYSTEM


The MI will go off after the vehicle is driven 3 times with no malfunction. The drive is counted only when
the recorded driving pattern is met (as stored in the ECM). If another malfunction occurs while counting,
the counter will reset.

The DTC and the freeze frame data will be stored until the vehicle is driven 40 times (driving pattern A)
without the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and
Fuel Injection System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times
(driving pattern C) without the same malfunction recurring. The “TIME” in “SELF-DIAGNOSTIC
RESULTS” mode of CONSULT-II will count the number of times the vehicle is driven.

The 1st trip DTC is not displayed when the self-diagnosis results in OK for the 2nd trip.
SUMMARY CHART
For details about patterns B and C under “Fuel Injection System” and “Misfire”, see EC-70 .
For details about patterns A and B under “Other”, see EC-72
.
*1: Clear timing is at the moment OK is detected.
*2: Clear timing is when the same malfunction is detected in the 2nd trip.Items Fuel Injection System Misfire Other
MI (goes off) 3 (pattern B) 3 (pattern B) 3 (pattern B)
DTC, Freeze Frame Data (no
display)80 (pattern C) 80 (pattern C) 40 (pattern A)
1st Trip DTC (clear)
1 (pattern C), *
11 (pattern C), *11 (pattern B)
1st Trip Freeze Frame Data
(clear)*
1 , *2*1 , *21 (pattern B)

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-69
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RELATIONSHIP BETWEEN MI, DTC, 1ST TRIP DTC AND DRIVING PATTERNS FOR “MISFIRE”
, “FUEL INJECTION SYSTEM”
*1: When the same malfunction is
detected in two consecutive trips, MI
will light up.*2: MI will go off after vehicle is driven 3
times (pattern B) without any mal-
functions.*3: When the same malfunction is
detected in two consecutive trips, the
DTC and the freeze frame data will
be stored in ECM.
*4: The DTC and the freeze frame data
will not be displayed any longer after
vehicle is driven 80 times (pattern C)
without the same malfunction. (The
DTC and the freeze frame data still
remain in ECM.)*5: When a malfunction is detected for
the first time, the 1st trip DTC and
the 1st trip freeze frame data will be
stored in ECM.*6: The 1st trip DTC and the 1st trip
freeze frame data will be cleared at
the moment OK is detected.
*7: When the same malfunction is
detected in the 2nd trip, the 1st trip
freeze frame data will be cleared.*8: 1st trip DTC will be cleared when
vehicle is driven once (pattern C)
without the same malfunction after
DTC is stored in ECM.
SEF392SA

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-71
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RELATIONSHIP BETWEEN MI, DTC, 1ST TRIP DTC AND DRIVING PATTERNS EXCEPT FOR
“MISFIRE ”, “FUEL INJECTION SYSTEM”
*1: When the same malfunction is
detected in two consecutive trips, MI
will light up.*2: MI will go off after vehicle is driven 3
times (pattern B) without any mal-
functions.*3: When the same malfunction is
detected in two consecutive trips, the
DTC and the freeze frame data will
be stored in ECM.
*4: The DTC and the freeze frame data
will not be displayed any longer after
vehicle is driven 40 times (pattern A)
without the same malfunction.
(The DTC and the freeze frame data
still remain in ECM.)*5: When a malfunction is detected for
the first time, the 1st trip DTC and
the 1st trip freeze frame data will be
stored in ECM.*6: 1st trip DTC will be cleared after
vehicle is driven once (pattern B)
without the same malfunction.
*7: When the same malfunction is
detected in the 2nd trip, the 1st trip
freeze frame data will be cleared.
SEF393SA

TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT
EC-123
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TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTPFP:00006
DescriptionEBS010M6
Intermittent incidents (I/I) may occur. In many cases, the malfunction resolves itself (the part or circuit function
returns to normal without intervention). It is important to realize that the symptoms described in the customer's
complaint often do not recur on (1st trip) DTC visits. Realize also that the most frequent cause of I/I occur-
rences is poor electrical connections. Because of this, the conditions under which the incident occurred may
not be clear. Therefore, circuit checks made as part of the standard diagnostic procedure may not indicate the
specific malfunctioning area.
Common I/I Report Situations
Diagnostic ProcedureEBS010M7
1. INSPECTION START
Erase (1st trip) DTCs. Refer to EC-63, "
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMA-
TION" .
>> GO TO 2.
2. CHECK GROUND TERMINALS
Check ground terminals for corroding or loose connection.
Refer to GI-23, "
How to Perform Efficient Diagnosis for an Electrical Incident" , “Incident Simulation Tests”,
“Ground Inspection”.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. SEARCH FOR ELECTRICAL INCIDENT
Perform GI-23, "
How to Perform Efficient Diagnosis for an Electrical Incident" , “Incident Simulation Tests”.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace.
STEP in Work Flow Situation
II The CONSULT-II is used. The SELF-DIAG RESULTS screen shows time data other than [0] or [1t].
III The symptom described by the customer does not recur.
IV (1st trip) DTC does not appear during the DTC Confirmation Procedure.
VI The Diagnostic Procedure for PXXXX does not indicate the malfunctioning area.

POWER SUPPLY AND GROUND CIRCUIT
EC-131
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Component InspectionEBS010MA
ECM RELAY
1. Apply 12V direct current between ECM relay terminals 1 and 2.
2. Check continuity between relay terminals 3 and 5, 6 and 7.
3. If NG, replace ECM relay.
Ground Inspection EBS011V6
Ground connections are very important to the proper operation of electrical and electronic circuits. Ground
connections are often exposed to moisture, dirt and other corrosive elements. The corrosion (rust) can
become an unwanted resistance. This unwanted resistance can change the way a circuit works.
Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can drasti-
cally affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit. Even
when the ground connection looks clean, there can be a thin film of rust on the surface.
When inspecting a ground connection follow these rules:

Remove the ground bolt or screw.

Inspect all mating surfaces for tarnish, dirt, rust, etc.

Clean as required to assure good contact.

Reinstall bolt or screw securely.

Inspect for “add-on” accessories which may be interfering with the ground circuit.

If several wires are crimped into one ground eyelet terminal, check for proper crimps. Make sure all of the
wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one
eyelet make sure no ground wires have excess wire insulation.
For detailed ground distribution information, refer to PG-13, "
Ground Distribution" .
Condition Continuity
12V direct current supply between
terminals 1 and 2Ye s
OFF No
PBIB0077E
PBIB1870E