
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

Self-diagnosis resultExample
DiagnosisIgnition cycle
¬ON®OFF¬ON®OFF¬ON®OFF¬ON®
All OK Case 1 P0400 OK (1) Ð (1) OK (2) Ð (2)
P0402 OK (1) Ð (1) Ð (1) OK (2)
P1402 OK (1) OK (2) Ð (2) Ð (2)
SRT of EGR ªCMPLTº ªCMPLTº ªCMPLTº ªCMPLTº
Case 2 P0400 OK (1) Ð (1) Ð (1) Ð (1)
P0402 Ð (0) Ð (0) OK (1) Ð (1)
P1402 OK (1) OK (2) Ð (2) Ð (2)
SRT of EGR ªINCMPº ªINCMPº ªCMPLTº ªCMPLTº
NG exists Case 3 P0400 OK OK Ð Ð
P0402ÐÐÐÐ
P1402 NG Ð NGNG
(Consecutive
NG)
(1st trip)
DTC1st trip DTC Ð 1st trip DTCDTC
(= MIL ªONº)
SRT of EGR ªINCMPº ªINCMPº ªINCMPº ªCMPLTº
OK: Self-diagnosis is carried out and the result is OK.
NG: Self-diagnosis is carried out and the result is NG.
Ð: Self-diagnosis is not carried out.
When all SRT related self-diagnoses showed OK results in a single cycle (Ignition OFF-ON-OFF), the SRT
will indicate ªCMPLTº.®Case 1 above
When all SRT related self-diagnoses showed OK results through several different cycles, the SRT will indi-
cate ªCMPLTº at the time the respective self-diagnoses have at least one OK result.®Case 2 above
If one or more SRT related self-diagnoses showed NG results in 2 consecutive cycles, the SRT will also indi-
cate ªCMPLTº.®Case 3 above
The table above shows that the minimum number of cycles for setting SRT as ªINCMPº is one (1) for each
self-diagnosis (Case1&2)ortwo(2)foroneofself-diagnoses (Case 3). However, in preparation for the state
emissions inspection, it is unnecessary of each self-diagnosis to be executed twice (Case 3) for the following
reasons:
+The SRT will indicate ªCMPLTº at the time the respective self-diagnoses have one (1) OK result.
+The emissions inspection requires ªCMPLTº of the SRT only with OK self-diagnosis results.
+When, during SRT driving pattern, 1st trip DTC (NG) is detected prior to ªCMPLTº of SRT, the self-diag-
nosis memory must be erased from ECM after repair.
+If the 1st trip DTC is erased, all the SRT will indicate ªINCMPº.
NOTE:
SRT can be set as ªCMPLTº together with the DTC(s). Therefore, DTC check must always be carried out prior
to the state emission inspection even though the SRT indicates ªCMPLTº.
SRT Service ProcedureNLEC0031S0109If a vehicle has failed the state emissions inspection due to one or more SRT items indicating ªINCMPº, review
the flowchart diagnostic sequence on the next page.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
Emission-related Diagnostic Information (Cont'd)
EC-63

SEF821Y
2.With GST
Selecting Mode 1 with GST (Generic Scan Tool)
How to Set SRT CodeNLEC0031S0111To set all SRT codes, self-diagnosis for the items indicated above must be performed one or more times. Each
diagnosis may require a long period of actual driving under various conditions.
With CONSULT-II
Perform corresponding DTC Confirmation Procedure one by one based on ªPerformance Priorityº in the table
on EC-122.
Without CONSULT-II
The most efficient driving pattern in which SRT codes can be properly set is explained on the next page. The
driving pattern should be performed one or more times to set all SRT codes.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
Emission-related Diagnostic Information (Cont'd)
EC-65

DTC Work Support ModeNLEC0034S0802
TEST MODE TEST ITEM CONDITION REFERENCE PAGE
HEATED OXYGEN
SENSOR 1 (FRONT)HO2S1 (B1) P0130
Refer to corresponding
trouble diagnosis for DTC.EC-184
HO2S1 (B1) P0131 EC-192
HO2S1 (B1) P0132 EC-198
HO2S1 (B1) P0133 EC-204
HEATED OXYGEN
SENSOR 2 (REAR)HO2S2 (B1) P0137 EC-227
HO2S2 (B1) P0138 EC-237
HO2S2 (B1) P0139 EC-246
EGR SYSTEM
(where fitted)EGR SYSTEM P0400 EC-310
EGR SYSTEM P1402 EC-393
SEF705Y
SEF707X
REAL TIME DIAGNOSIS IN DATA MONITOR MODE
(RECORDING VEHICLE DATA)
NLEC0034S10CONSULT-II has two kinds of triggers and they can be selected by
touching ªSETTINGº in ªDATA MONITORº mode.
1) ªAUTO TRIGº (Automatic trigger):
+The malfunction will be identified on the CONSULT-II screen in
real time.
In other words, DTC/1st trip DTC and malfunction item will be
displayed if the malfunction is detected by ECM.
At the moment a malfunction is detected by ECM, ªMONITORº
in ªDATA MONITORº screen is changed to ªRecording Data ...
xx%º as shown at left, and the data after the malfunction detec-
tion is recorded. Then when the percentage reached 100%,
ªREAL-TIME DIAGº screen is displayed. If ªSTOPº is touched
on the screen during ª Recording Data ... xx%º, ªREAL-TIME
DIAGº screen is also displayed.
The recording time after the malfunction detection and the
recording speed can be changed by ªTRIGGER POINTº and
ªRecording Speedº. Refer to CONSULT-II OPERATION
MANUAL.
2) ªMANU TRIGº (Manual trigger):
+DTC/1st trip DTC and malfunction item will not be displayed
automatically on CONSULT-II screen even though a malfunc-
tion is detected by ECM.
DATA MONITOR can be performed continuously even though
a malfunction is detected.
Use these triggers as follows:
1) ªAUTO TRIGº
+While trying to detect the DTC/1st trip DTC by performing the
ªDTC Confirmation Procedureº, be sure to select to ªDATA
MONITOR (AUTO TRIG)º mode. You can confirm the malfunc-
tion at the moment it is detected.
+While narrowing down the possible causes, CONSULT-II
should be set in ªDATA MONITOR (AUTO TRIG)º mode, espe-
cially in case the incident is intermittent.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG18DE
CONSULT-II (Cont'd)
EC-91

MEF036D
SEF233G
SEF234G
IntroductionNLEC0036The engine has an ECM to control major systems such as fuel
control, ignition control, idle air control system, etc. The ECM
accepts input signals from sensors and instantly drives actuators.
It is essential that both input and output signals are proper and
stable. At the same time, it is important that there are no problems
such as vacuum leaks, fouled spark plugs, or other problems with
the engine.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this
case, careful checking of suspected circuits may help prevent the
replacement of good parts.
A visual check only may not find the cause of the problems. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the ªWork Flowº on EC-97.
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 problems, espe-
cially intermittent ones. Find out what symptoms are present and
under what conditions they occur. A ªDiagnostic Worksheetº like the
example on next page should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
SEF907L
DIAGNOSTIC WORKSHEETNLEC0036S01There are many operating conditions that lead to the malfunction
of engine components. A good grasp of such conditions can make
trouble-shooting faster and more accurate.
In general, each customer feels differently about a problem. It is
important to fully understand the symptoms or conditions for a
customer 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 malfunction indicator lamp to
come on steady or blink and DTC to be detected.
Example:
Vehicle ran out of fuel, which caused the engine to misfire.
TROUBLE DIAGNOSIS Ð INTRODUCTIONQG18DE
EC-95

19 CHECK IGNITION TIMING-I
1. Turn ignition switch ªOFFº.
2. Release vacuum from throttle opener.
3. Remove vacuum pump and vacuum hose from throttle opener.
4. Reinstall original vacuum hose to throttle opener securely.
5. Start engine and warm it up to normal operating temperature.
6. Stop engine and disconnect throttle position sensor harness connector.
JEF091Y
7. Start engine.
8. Check ignition timing at idle using a timing light.
SEF984U
Ignition timing:
8±2É BTDC
OK or NG
OK©GO TO 24.
NG©GO TO 20.
20 DETECT MALFUNCTIONING PART
Check the following.
+Crankshaft position sensor (POS) circuit and function. Refer to EC-295.
+Camshaft position sensor (PHASE) circuit and function. Refer to EC-302.
OK or NG
OK©GO TO 22.
NG©GO TO 21.
21 REPAIR MALFUNCTION
Repair or replace malfunctioning part following the ªDiagnostic Procedureº corresponding the detected malfunction.
©GO TO 23.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG18DE
Basic Inspection (Cont'd)
EC-110

26 CHECK IGNITION TIMING AGAIN
Check ignition timing again. Refer to Test No. 24.
OK or NG
OK (With CONSULT-II)©GO TO 32.
OK (Without CONSULT-
II)©GO TO 35.
NG©GO TO 27.
27 CHECK FOR INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an air leak from PCV hose and after IACV-AAC valve.
OK or NG
OK©GO TO 29.
NG©GO TO 28.
28 REPAIR MALFUNCTION
1. Stop engine.
2. Repair or replace malfunctioning part.
©GO TO 25.
29 DETECT MALFUNCTIONING PART
Check the IACV-AAC valve circuit and function. Refer to EC-343.
OK or NG
OK©GO TO 31.
NG©GO TO 30.
30 REPAIR MALFUNCTION
Repair or replace malfunction part following the ªDiagnostic Procedureº corresponding the detected malfunction.
©GO TO 25.
31 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function.
(ECM may be the cause of a problem, but this is rarely the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-72.
©GO TO 25.
32 CHECK TARGET IDLE SPEED
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode.
3. Check idle speed.
700±50 rpm
OK or NG
OK©GO TO 38.
NG©GO TO 33.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG18DE
Basic Inspection (Cont'd)
EC-112

7 CHECK INPUT SIGNAL CIRCUIT
1. Check harness continuity between mass air flow sensor harness connector terminal 1 and ECM terminal 61.
Refer to wiring diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 8.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
8 CHECK MASS AIR FLOW SENSOR
Refer to ªComponent Inspectionº, EC-160.
OK or NG
OK©GO TO 9.
NG©Replace mass air flow sensor.
9 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-145.
©INSPECTION END
SEF993W
SEF987W
Component InspectionNLEC0058MASS AIR FLOW SENSORNLEC0058S011. Turn ignition switch ªONº.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 61 (Mass air flow sen-
sor signal) and ground.
Conditions Voltage V
Ignition switch ªONº (Engine stopped.) Less than 1.2
Idle (Engine is warmed-up to normal operating
temperature.)1.0 - 1.7
2,500 rpm (Engine is warmed-up to normal oper-
ating temperature.)1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.7 to Approx. 4.0
*: Check for linear voltage rise in response to increases to about 4,000 rpm in
engine speed.
4. If the voltage is out of specification, disconnect mass air flow
sensor harness connector and connect it again. Repeat above
check.
5. If NG, remove mass air flow sensor from air duct. Check hot
film for damage or dust.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG18DE
Diagnostic Procedure (Cont'd)
EC-160