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2) Touch ªENGINEº.
3) Touch ªSELF-DIAG RESULTSº.
4) Touch ªERASEº. (The DTC in the ECM will be erased.)
SEF993XA
The emission related diagnostic information in the ECM can be erased by selecting ªERASEº in the ªSELF-
DIAG RESULTSº mode with CONSULT-II.
How to Erase DTC (
Without CONSULT-II)
1) If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
10 seconds and then turn it ªONº (engine stopped) again.
2) Change the diagnostic test mode from Mode II to Mode I by using the data link connector. (See EC-75.)
The emission related diagnostic information in the ECM can be erased by changing the diagnostic test mode.
+If the battery is disconnected, the emission-related diagnostic information will be lost after approx.
24 hours.
+Erasing the emission-related diagnostic information using CONSULT-II is easier and quicker than
switching the diagnostic test mode using the data link connector.
+The following data are cleared when the ECM memory is erased.
1) Diagnostic trouble codes
2) 1st trip diagnostic trouble codes
3) Freeze frame data
4) 1st trip freeze frame data
5) Others
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.
SEF543X
NATS (Nissan Anti-theft System)NLEC0591+If the security indicator lights up with the ignition switch
in the ªONº position or ªNATS MALFUNCTIONº is dis-
played on ªSELF-DIAG RESULTSº screen, perform self-
diagnostic results mode with CONSULT-II using NATS pro-
gram card. Refer to NATS (Nissan Anti-Theft System) in EL
section.
+Confirm no self-diagnostic results of NATS is displayed
before touching ªERASEº in ªSELF-DIAG RESULTSº
mode with CONSULT-II.
+When replacing ECM, initialization of NATS system and
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
Emission-related Diagnostic Information (Cont'd)
EC-72
Page 498 of 3051
registrationof al lN ATS ignitio nke yID smus tbe carried
SAT652J
MI Condition
NATS (Nissan Anti-theft System) (Cont'd)
Page 499 of 3051
Condition Diagnostic Test Mode I Diagnostic Test Mode II
Ignition switch in ªONº position
Engine stopped
BULB CHECK SELF-DIAGNOSTIC RESULTS
Engine running
MALFUNCTION WARNINGHEATED OXYGEN SENSOR 1
MONITOR (FRONT)
The following emission-related diagnostic information is cleared when the ECM memory is erased.
1) Diagnostic trouble codes
2) 1st trip diagnostic trouble codes
3) Freeze frame data
4) 1st trip freeze frame data
5) System readiness test (SRT) codes
6) Test values
7) Distance traveled while MI is activated
8) Others
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
Malfunction Indicator (MI) (Cont'd)
EC-74
Page 500 of 3051
How to Switch Diagnostic Test ModesNLEC0032S02
SEF951WA
*1: EC-545
*2: EC-73*3: EC-545 *4: EC-123
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
Malfunction Indicator (MI) (Cont'd)
EC-75
Page 501 of 3051
DiagnosticTes tMod eIÐ BulbCheck
MI Condition
SEF952W
Malfunction Indicator (MI) (Cont'd)
Page 502 of 3051

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
*: Maintains conditions just before switching to open loop.
To check the heated oxygen sensor 1 (front) 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 Chart (With Euro-OBD
Models Only)
NLEC0033RELATIONSHIP BETWEEN MI, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMSNLEC0033S01+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 ªTwo Trip Detection Logicº on
EC-59.
+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 (driv-
ing pattern C) without the same malfunction recurring. The ªTIMEº in ªSELF-DIAGNOSTIC RESULTSº
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 ªOKº for the 2nd trip.
SUMMARY CHARTNLEC0033S02
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)
For details about patterns ªBº and ªCº under ªFuel Injection Systemº and ªMisfireº, see EC-79.
For details about patterns ªAº and ªBº under ªOtherº, see EC-81.
*1: Clear timing is at the moment OK is detected.
*2: Clear timing is when the same malfunction is detected in the 2nd trip.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
Malfunction Indicator (MI) (Cont'd)
EC-77
Page 503 of 3051

RELATIONSHIP BETWEEN MI, DTC, 1ST TRIP DTC AND DRIVING PATTERNS FOR
ªMISFIREº , ªFUEL INJECTION SYSTEMº
NLEC0033S03
SEF392SA
*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
malfunctions.
*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 framedata 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 tripfreeze 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.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
OBD System Operation Chart (With Euro-OBD Models Only) (Cont'd)
EC-78
Page 504 of 3051

EXPLANATION FOR DRIVING PATTERNS FOR ªMISFIRE
DETERIORATION>º, ªFUEL INJECTION SYSTEMº
NLEC0033S04Driving Pattern BNLEC0033S0401Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.
+The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
+The B counter will be counted up when driving pattern B is satisfied without any malfunction.
+The MI will go off when the B counter reaches 3. (*2 in EC-78)
Driving Pattern CNLEC0033S0402Driving pattern C means the vehicle operation as follows:
1) The following conditions should be satisfied at the same time:
Engine speed: (Engine speed in the freeze frame data)±375 rpm
Calculated load value: (Calculated load value in the freeze frame data)´(1±0.1) [%]
Engine coolant temperature (T) condition:
+When the freeze frame data shows lower than 70ÉC (158ÉF), ªTº should be lower than 70ÉC (158ÉF).
+When the freeze frame data shows higher than or equal to 70ÉC (158ÉF), ªTº should be higher than or
equal to 70ÉC (158ÉF).
Example:
If the stored freeze frame data is as follows:
Engine speed: 850 rpm, Calculated load value: 30%, Engine coolant temperature: 80ÉC (176ÉF)
To be satisfied with driving pattern C, the vehicle should run under the following conditions:
Engine speed: 475 - 1,225 rpm, Calculated load value: 27 - 33%, Engine coolant temperature: more than 70ÉC
(158ÉF)
+The C counter will be cleared when the malfunction is detected regardless of driving pattern C.
+The C counter will be counted up when driving pattern C is satisfied without the same malfunction.
+The DTC will not be displayed after C counter reaches 80.
+The 1st trip DTC will be cleared when C counter is counted once without the same malfunction after DTC
is stored in ECM.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
OBD System Operation Chart (With Euro-OBD Models Only) (Cont'd)
EC-79