
The ªtripº in the ªTwo Trip Detection Logicº means a driving mode in which self-diagnosis is performed during
vehicle operation. Specific on board diagnostic items will cause the ECM to light up or blink the MI, and store
DTC and Freeze Frame data, even in the 1st trip, as shown below.
X: Applicable Ð: Not applicable
ItemsMI DTC 1st trip DTC
1st trip 2nd trip
1st trip
displaying2nd trip
displaying1st trip
displaying2nd trip
displaying
BlinkingLighting
upBlinkingLighting
up
Misfire (Possible three way
catalyst damage)
Ð DTC: P0300 - P0304 is
being detectedX ÐÐÐÐÐ X Ð
Misfire (Possible three way
catalyst damage)
Ð DTC: P0300 - P0304 is
being detectedÐÐXÐÐXÐÐ
Fail-safe items (Refer to
EC-123.)Ð X Ð Ð X*1 Ð X*1 Ð
Except above Ð ÐÐXÐX XÐ
*1: Except ªECMº.
MODELS WITHOUT EURO-OBD SYSTEMNLEC0030S02When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in
the ECM memory. <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. <2nd trip> The ªtripº in the ªTwo Trip Detection Logicº means a driving mode in which
self-diagnosis is performed during vehicle operation. When the ECM enters the fail-safe mode (Refer to
EC-123), the DTC is stored in the ECM memory even in the 1st trip.
Emission-related Diagnostic InformationNLEC0031MODELS WITH EURO-OBD SYSTEMNLEC0031S01DTC and 1st Trip DTCNLEC0031S0101The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, the 1st trip
DTC will not be displayed. If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM
memory. The MI will not light up (two trip detection logic). If the same malfunction is not detected in the 2nd
trip (meeting the required driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same mal-
function is detected in the 2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MI
lights up. In other words, the DTC is stored in the ECM memory and the MI lights up when the same malfunc-
tion occurs in two consecutive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed
between the 1st and 2nd trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or
light up the MI during the 1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in ªHow to Erase
Emission-related Diagnostic Informationº. Refer to EC-69.
For malfunctions in which 1st trip DTCs are displayed, refer to EC-68. These items are required by legal
regulations to continuously monitor the system/component. In addition, the items monitored non-continuously
are also displayed on CONSULT-II.
1st trip DTC is specified in Mode 7 of ISO 15031-5. 1st trip DTC detection occurs without lighting up the MI
and therefore does not warn the driver of a problem. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in ªWork Flowº procedure Step II, refer to page EC-97. Then perform ªDTC Confirmation
Procedureº or ªOverall Function Checkº to try to duplicate the problem. If the malfunction is duplicated, the
item requires repair.
How to read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.
With CONSULT-II/With GST
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
Two Trip Detection Logic (Cont'd)
EC-60

System Readiness Test (SRT) CodeNLEC0031S0103System Readiness Test (SRT) code is specified in Mode 1 of ISO 15031-5.
As part of an emissions test for Inspection & Maintenance (I/M), certain states require the status of SRT be
used to indicate whether the ECM has completed self-diagnosis of major emission systems and components.
Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating ªINCMPº,
use the information in this Service Manual to set the SRT to ªCMPLTº.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate ªCMPLTº for each application system. Once set as ªCMPLTº, the SRT status remains
ªCMPLTº 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 ªINCMPº for these items.
NOTE:
The SRT will also indicate ªINCMPº if the self-diagnosis memory is erased for any reason or if the ECM
memory power supply is interrupted for several hours.
If, during the state emissions inspection, the SRT indicates ªCMPLTº for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indicates ªINCMPº for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MI is ªONº during the state emissions inspection, the vehicle is also returned to the customer untested even
though the SRT indicates ªCMPLTº for all test items. Therefore, it is important to check SRT (ªCMPLTº) and
DTC (No DTCs) before the inspection.
SRT ItemNLEC0031S0107The table below shows required self-diagnostic items to set the SRT to ªCMPLTº.
SRT item
(CONSULT-II indica-
tion)Perfor-
mance Pri-
ority*1Required self-diagnostic items to set the SRT to ªCMPLTºCorresponding
DTC No.
CATALYST 3 Three way catalyst function P0420
O2 SENSOR 3 Heated oxygen sensor 1 (front) (circuit) P0130
Heated oxygen sensor 1 (front) (lean shift monitoring) P0131
Heated oxygen sensor 1 (front) (rich shift monitoring) P0132
Heated oxygen sensor 1 (front) (response monitoring) P0133
Heated oxygen sensor 1 (front) (high voltage) P0134
Heated oxygen sensor 2 (rear) (min. voltage monitoring) P0137
Heated oxygen sensor 2 (rear) (max. voltage monitoring) P0138
Heated oxygen sensor 2 (rear) (response monitoring) P0139
Heated oxygen sensor 2 (rear) (high voltage) P0140
O2 SEN HEATER 3 Heated oxygen sensor 1 heater (front) P0135
Heated oxygen sensor 1 heater (rear) P0141
EGR SYSTEM
(where fitted)3 EGR function (close) P0400
1 EGR function (open) P1402
*1: 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 TimingNLEC0031S0108SRT is set as ªCMPLTº 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.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
Emission-related Diagnostic Information (Cont'd)
EC-62

Basic InspectionNLEC0564MODELS WITH THROTTLE POSITION SWITCH AND
THROTTLE OPENER
NLEC0564S01Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
+Headlamp switch is OFF,
On vehicle equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.
+Air conditioner switch is OFF,
+Rear window defogger switch is OFF,
+Steering wheel is in the straight-ahead position, etc.
1 INSPECTION START
1. Check service records for any recent repairs that may indicate a related problem, or a current need for scheduled
maintenance.
2. Open engine hood and check the following:
+Harness connectors for improper connections
+Vacuum hoses for splits, kinks and improper connections
+Wiring for improper connections, pinches and cuts
+Air cleaner clogging
+Hoses and ducts for leaks
SEF983U
©GO TO 2.
2 CHECK THROTTLE OPENER OPERATION-I
Confirm that there is a clearance between throttle drum and stopper.
SEF850Y
OK or NG
OK©GO TO 4.
NG©GO TO 3.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG18DE
Basic Inspection
EC-99

MODELS WITHOUT THROTTLE POSITION SWITCH AND
THROTTLE OPENER
NLEC0564S02Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
+Headlamp switch is OFF,
On vehicle equipped with daytime light system, set lighting
switch to the 1st position to light only small lamps.
+Air conditioner switch is OFF,
+Rear window defogger switch is OFF,
+Steering wheel is in the straight-ahead position, etc.
1 INSPECTION START
1. Check service records for any recent repairs that may indicate a related problem, or a current need for scheduled
maintenance.
2. Open engine hood and check the following:
+Harness connectors for improper connections
+Vacuum hoses for splits, kinks and improper connections
+Wiring for improper connections, pinches and cuts
+Air cleaner clogging
+Hoses and ducts for leaks
SEF983U
©GO TO 2.
2 CHECK THROTTLE DRUM OPERATION-I
Confirm that throttle drum is in contact with the stopper.
OK or NG
OK (with CONSULT-II)©GO TO 5.
OK (without CONSULT-
II)©GO TO 8.
NG©GO TO 3.
3 CHECK ACCELERATOR WIRE INSTALLATION
Check accelerator wire for slack.
OK or NG
OK©GO TO 4.
NG©Adjust accelerator wire. Refer to FE section, ªAdjusting Accelerator Wireº.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG18DE
Basic Inspection (Cont'd)
EC-114

4 CHECK FUEL PRESSURE
1. Release fuel pressure to zero.
Refer to EC-43.
2. Install fuel pressure gauge and check fuel pressure.
At idling:
When fuel pressure regulator valve vacuum hose is connected.
235 kPa (2.35 bar, 2.4 kg/cm
2, 34 psi)
When fuel pressure regulator valve vacuum hose is disconnected.
294 kPa (2.94 bar, 3.0 kg/cm
2, 43 psi)
OK or NG
OK©GO TO 6.
NG©GO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
+Fuel pump and circuit (Refer to EC-516.)
+Fuel pressure regulator (Refer to EC-44.)
+Fuel lines (Refer to ªENGINE MAINTENANCEº in MA section.)
+Fuel filter for clogging
©Repair or replace.
6 CHECK MASS AIR FLOW SENSOR
With CONSULT-II
Check ªMASS AIR FLOWº in ªDATA MONITORº mode with CONSULT-II.
at idling: 1.0 - 4.0 g´m/sec
at 2,500 rpm: 5.0 - 10.0 g´m/sec
With GST
Check mass air flow sensor signal in MODE 1 with GST.
at idling: 1.0 - 4.0 g´m/sec
at 2,500 rpm: 5.0 - 10.0 g´m/sec
OK or NG
OK©GO TO 7.
NG©Check connectors for rusted terminals or loose connections in the mass air flow sensor
circuit or engine grounds. Refer to EC-154.
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
(LEAN SIDE)
QG18DE
Diagnostic Procedure (Cont'd)
EC-274

Precautions for Supplemental Restraint System
(SRS) ªAIR BAGº and ªSEAT BELT
PRE-TENSIONERº
NLEC1745The Supplemental Restraint System ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº, used along with a seat
belt, help to reduce the risk or severity of injury to the driver and front passenger in a frontal collision. The
Supplemental Restraint System consists of air bag modules (located in the center of the steering wheel and
on the instrument panel on the passenger side), seat belt pre-tensioners, a diagnosis sensor unit, warning
lamp, wiring harness and spiral cable.
In addition to the supplemental air bag modules for a frontal collision, the supplemental side air bag used along
with the seat belt helps to reduce the risk or severity of injury to the driver and front passenger in a side col-
lision. The supplemental side air bag consists of air bag modules (located in the outer side of front seats),
satellite sensor, diagnosis sensor unit (one of components of supplemental air bags for a frontal collision),
wiring harness, warning lamp (one of components of supplemental air bags for a frontal collision). Information
necessary to service the system safely is included in theRS sectionof this Service Manual.
WARNING:
+To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be performed
by an authorized NISSAN dealer.
+Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system.
+Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified with yellow harness connector (and with
yellow harness protector or yellow insulation tape before the harness connectors).
Precautions for On Board Diagnostic (OBD)
System of Engine and CVT
NLEC1332The ECM has an on board diagnostic system. It will light up the malfunction indicator (MI) to warn the driver
of a malfunction causing emission deterioration.
CAUTION:
+Be sure to turn the ignition switch ªOFFº and disconnect the negative battery terminal before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc.
will cause the MI to light up.
+Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MI to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
+Certain systems and components, especially those related to OBD, may use a new style slide-
locking type harness connector.
For description and how to disconnect, refer to EL section, ªDescriptionº, ªHARNESS CONNEC-
TORº.
+Be sure to route and secure the harnesses properly after work. The interference of the harness with
a bracket, etc. may cause the MI to light up due to the short circuit.
+Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MI to light up due to the malfunction of fuel injection system, etc.
+Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and
TCM (Transmission Control Module) before returning the vehicle to the customer.
PRECAUTIONSSR20DE
Precautions for Supplemental Restraint System (SRS) ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº
EC-555

The ªtripº in the ªTwo Trip Detection Logicº means a driving mode in which self-diagnosis is performed during
vehicle operation. Specific on board diagnostic items will cause the ECM to light up or blink the MI, and store
DTC and Freeze Frame data, even in the 1st trip, as shown below.
X: Applicable Ð: Not applicable
ItemsMI DTC 1st trip DTC
1st trip 2nd trip
1st trip
displaying2nd trip
displaying1st trip
displaying2nd trip
displaying
BlinkingLighting
upBlinkingLighting
up
Misfire (Possible three way
catalyst damage)
Ð DTC: P0300 - P0304 is
being detectedX ÐÐÐÐÐ X Ð
Misfire (Possible three way
catalyst damage)
Ð DTC: P0300 - P0304 is
being detectedÐÐXÐÐXÐÐ
Fail-safe items (Refer to
EC-647.)Ð X Ð Ð X*1 Ð X*1 Ð
Except above Ð ÐÐXÐX XÐ
*1: Except ªECMº.
MODELS WITHOUT EURO-OBD SYSTEMNLEC1360S02When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in
the ECM memory. <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. <2nd trip> The ªtripº in the ªTwo Trip Detection Logicº means a driving mode in which
self-diagnosis is performed during vehicle operation. When the ECM enters the fail-safe mode (Refer to
EC-647), the DTC is stored in the ECM memory even in the 1st trip.
Emission-related Diagnostic InformationNLEC1361MODELS WITH EURO-OBD SYSTEMNLEC1361S01DTC and 1st Trip DTCNLEC1361S0101The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, the 1st trip
DTC will not be displayed. If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM
memory. The MI will not light up (two trip detection logic). If the same malfunction is not detected in the 2nd
trip (meeting the required driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same mal-
function is detected in the 2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MI
lights up. In other words, the DTC is stored in the ECM memory and the MI lights up when the same malfunc-
tion occurs in two consecutive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed
between the 1st and 2nd trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or
light up the MI during the 1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in ªHow to Erase
Emission-related Diagnostic Informationº. Refer to EC-594.
For malfunctions in which 1st trip DTCs are displayed, refer to EC-592. These items are required by legal
regulations to continuously monitor the system/component. In addition, the items monitored non-continuously
are also displayed on CONSULT-II.
1st trip DTC is specified in Mode 7 of ISO 15031-5. 1st trip DTC detection occurs without lighting up the MI
and therefore does not warn the driver of a problem. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in ªWork Flowº procedure Step II, refer to page EC-621. Then perform ªDTC Confirmation
Procedureº or ªOverall Function Checkº to try to duplicate the problem. If the malfunction is duplicated, the
item requires repair.
How to read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.
With CONSULT-II/With GST
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONSR20DE
Two Trip Detection Logic (Cont'd)
EC-584

System Readiness Test (SRT) CodeNLEC1361S0103System Readiness Test (SRT) code is specified in Mode 1 of ISO 15031-5.
As part of an emissions test for Inspection & Maintenance (I/M), certain states require the status of SRT be
used to indicate whether the ECM has completed self-diagnosis of major emission systems and components.
Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating ªINCMPº,
use the information in this Service Manual to set the SRT to ªCMPLTº.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate ªCMPLTº for each application system. Once set as ªCMPLTº, the SRT status remains
ªCMPLTº 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 ªINCMPº for these items.
NOTE:
The SRT will also indicate ªINCMPº if the self-diagnosis memory is erased for any reason or if the ECM
memory power supply is interrupted for several hours.
If, during the state emissions inspection, the SRT indicates ªCMPLTº for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indicates ªINCMPº for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MI is ªONº during the state emissions inspection, the vehicle is also returned to the customer untested even
though the SRT indicates ªCMPLTº for all test items. Therefore, it is important to check SRT (ªCMPLTº) and
DTC (No DTCs) before the inspection.
SRT ItemNLEC1361S0104The table below shows required self-diagnostic items to set the SRT to ªCMPLTº.
SRT item
(CONSULT-II indica-
tion)Perfor-
mance Pri-
ority*1Required self-diagnostic items to set the SRT to ªCMPLTºCorresponding
DTC No.
CATALYST 3 Three way catalyst function P0420
O2 SENSOR 3 Heated oxygen sensor 1 (front) (circuit) P0130
Heated oxygen sensor 1 (front) (lean shift monitoring) P0131
Heated oxygen sensor 1 (front) (rich shift monitoring) P0132
Heated oxygen sensor 1 (front) (response monitoring) P0133
Heated oxygen sensor 1 (front) (high voltage) P0134
Heated oxygen sensor 2 (rear) (min. voltage monitoring) P0137
Heated oxygen sensor 2 (rear) (max. voltage monitoring) P0138
Heated oxygen sensor 2 (rear) (response monitoring) P0139
Heated oxygen sensor 2 (rear) (high voltage) P0140
O2 SEN HEATER 3 Front heated oxygen sensor 1 heater (front) P0135
Rear heated oxygen sensor 1 heater (rear) P0141
EGR SYSTEM 3 EGR function (close) P0400
1 EGR function (open) P1402
*1: 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.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONSR20DE
Emission-related Diagnostic Information (Cont'd)
EC-586