2003 NISSAN ALMERA N16 ECU

EC-50
[QG (WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
When there is an open circuit on MI circuit, the ECM cannot warn the driver by lighting MI up when there is
malfunction 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 malfunctions and MI circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MI circuit and demands the driver to repair
the malfunction.
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-51, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .
How to switch the diagnostic test (function) modes, and details of the above functions are described later, EC-
51, "HOW TO SWITCH DIAGNOSTIC TEST MODE" .
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
●Others
Diagnostic Test
ModeKEY and ENG.
Sta tusFunction 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

EC-52
[QG (WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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
malfunction. (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-
51, "HOW TO SWITCH DIAGNOSTIC TEST MODE" .
●If the battery is disconnected, the DTC will be lost from the backup memory after approx 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 ChartEBS00K3K
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-36, "
Two Trip Detection
Logic" .
SEF952W
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

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-53
[QG (WITH EURO-OBD)]
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EC
●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-55 .
For details about patterns “A” and “B” under “Other”, see EC-57
.
*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), *1 1 (pattern C), *1 1 (pattern B)
1st Trip Freeze Frame Data
(clear)*1, *2 *1, *2 1 (pattern B)

EC-54
[QG (WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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

EC-56
[QG (WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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-109
[QG (WITH EURO-OBD)]
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EC
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTPFP:00006
DescriptionEBS00K42
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 ProcedureEBS00K43
1.INSPECTION START
Erase (1st trip) DTCs. Refer to EC-48, "
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, “Incident Simulation Tests”.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.SEARCH FOR ELECTRICAL INCIDENT
Perform GI-23, “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.

EC-120
[QG (WITH EURO-OBD)]
DTC P0011 IVT CONTROL
On Board Diagnosis Logic
EBS00K4E
The MI will not light up for this diagnosis.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation ProcedureEBS00K4F
CAUTION:
Always drive at a safe speed.
NOTE:
●If DTC P0011 is displayed with DTC P1111, first perform trouble diagnosis for “DTC P1111”. See
EC-272, "
DTC P1111 IVT CONTROL SOLENOID VALVE" .
●If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and
wait at least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is between 10V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch “ON” and select ″DATA MONITOR″ mode
with CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Maintain the following conditions for at least 20 consecutive sec-
onds.
4. Stop vehicle with engine running and let engine idle for 10 seconds.
5. If 1st trip DTC is detected, go to EC-121, "
Diagnostic Procedure" .
If 1st trip DTC is not detected, go to next step.
6. Maintain the following conditions for at least 10 consecutive seconds.
7. If 1st trip DTC is detected, go to EC-121, "
Diagnostic Procedure" .
DTC No. Trouble diagnosis name Detecting condition Possible cause
P0011
0011Intake valve timing con-
trol performanceThere is a gap between angle of target and
phase-control angle degree.
●Crankshaft position sensor (POS)
●Camshaft position sensor (PHASE)
●Accumulation of debris to the signal pick-up
portion of the camshaft
Detected items Engine operating condition in fail-safe mode
Intake valve timing control The signal is not energized to the solenoid valve and the valve control does not function
VHCL SPEED SE 100 - 120 km/h (63 - 75 MPH)
ENG SPEED 2,000 - 4,000 rpm
COOLANT TEMPS 60 - 120°C (140 - 248°F)
B/FUEL SCHDL More than 3.38 msec
Selector leverA/T models: D position
M/T models: 5th position
ENG SPEED 1,700 - 3,175 rpm (A constant rotation is maintained.)
COOLANT TEMPS 70 - 105°C (176 - 194°F)
Selector lever 1st or 2nd position
Driving location uphillDriving vehicle uphill
(Increased engine load will help maintain the driving
conditions required for this test.)
SEF174Y

EC-246
[QG (WITH EURO-OBD)]
DTC P0420 THREE WAY CATALYST FUNCTION
DTC P0420 THREE WAY CATALYST FUNCTION
PFP:20905
On Board Diagnosis LogicEBS00K8J
The ECM monitors the switching frequency ratio of heated oxygen
sensors 1 and 2.
A three way catalyst (Manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decreases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of heated oxygen sensors 1 and 2
approaches a specified limit value, the three way catalyst (Manifold)
malfunction is diagnosed.
DTC Confirmation ProcedureEBS00K8K
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
TESTING CONDITION:
●Open engine hood before conducting the following procedure.
●Do not hold engine speed for more than the specified minutes below.
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch ″OFF″ and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least one minute under no
load.
4. Let engine idle for one minute.
5. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUP-
PORT” mode with CONSULT-II.
6. Rev engine up to 2,500 to 3,500 rpm and hold it for 3 consecu-
tive minutes then release the accelerator pedal completely.
If “INCMP” of “CATALYST” changed to “COMPLT”, go to step 9
7. Wait 5 seconds at idle.
SEF484YF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420Catalyst system efficiency
below threshold
●Three way catalyst (Manifold) does not operate
properly.
●Three way catalyst (Manifold) does not have
enough oxygen storage capacity.
●Three way catalyst (Manifold)
●Exhaust tube
●Intake air leaks
●Fuel injectors
●Fuel injector leaks
●Spark plug
●Improper ignition timing
PBIB0566E