ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-39
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utive 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 inEC-46, "
HOW
TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION".
For malfunctions in which 1st trip DTCs are displayed, refer toEC-37
. These items are required by legal reg-
ulations 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 vehi-
cle 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 “Work Flow” procedure Step II, refer toEC-58
. Then perform “DTC Confirmation Proce-
dure” or “Overall Function Check” 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
CONSULT-II or GST (Generic Scan Tool) Examples: P0340, P0705, P0750, etc.
These DTCs are prescribed by ISO 15031-5.
(CONSULT-II also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MI in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0102, 0340 etc.
These DTCs are controlled by NISSAN.
l1st trip DTC No. is the same as DTC No.
lOutput of a DTC indicates a malfunction. However, GST or the Diagnostic Test Mode II do not indi-
cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-II can identify malfunction status as shown below. Therefore, using CONSULT-II (if
available) is recommended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown below. DTC or 1st trip DTC of a malfunc-
tion is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-II. Time data indicates how many times
the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be “0”.
Ifa1sttripDTCisstoredintheECM,thetimedatawillbe“[1t]”.
FREEZE FRMADE DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, base fuel schedule and intake
air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
details, seeEC-89
.
Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
SEF745C
EC-48
[QR (WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
5. System readiness test (SRT) codes
6. Test values
7. 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.
NATS (Nissan Anti-theft System)EBS00BM8
lIf 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 toBL-70, "
NATS (NISSAN ANTI-THEFT SYSTEM)".
lConfirm no self-diagnostic results of NATS is displayed
before touching “ERASE” in “SELF-DIAG RESULTS” mode
with CONSULT-II.
lWhen 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 NATS ignition key ID registration, refer to
CONSULT-II operation manual, NATS.
Malfunction Indicator (MI)EBS00BM9
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.
lIf the MI does not light up, refer toDI-39, "WARNING LAMPS",
or seeEC-252
.
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
Diagnostic Test
ModeKEY and ENG.
Statu sFunction 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.
l“Misfire (Possible three way catalyst damage)”
lFail-safe mode
TROUBLE DIAGNOSIS
EC-67
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10.CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light.
OK or NG
OK >>INSPECTION END
NG >> GO TO 11.
11 .PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. PerformEC-31, "
Accelerator Pedal Released Position Learning".
>> GO TO 12.
12.PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
1. Stop engine.
2. PerformEC-31, "
Throttle Valve Closed Position Learning".
>> GO TO 13.
13.PERFORM IDLE AIR VOLUME LEARNING
Refer toEC-31, "
Idle Air Volume Learning".
CMPLT or INCMP
CMPLT>>GOTO14.
INCMP >> 1. Follow the construction of “Idle Air Volume Learning”.
2. GO TO 4.
14.CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Wi t h ou t C O N S U LT-I I
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.M/T: 14±5°BTDC
A/T: 16±5°BTDC (in "P" or "N" position)
Which is the result CMPLT or INCMP
M/T: 650±50 rpm
A/T: 700±50 rpm (in "P" or "N" position)
M/T: 650±50 rpm
A/T: 700±50 rpm (in "P" or "N" position)
EC-68
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TROUBLE DIAGNOSIS
15.CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
OK or NG
OK >>INSPECTION END
NG >> GO TO 16.
16.CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer toEM-43, "
TIMING CHAIN".
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation.
2. GO TO 4.
17.DETECT MALFUNCTIONING PART
Check the following.
lCheck camshaft position sensor (PHASE) and circuit. Refer toEC-223.
lCheck crankshaft position sensor (POS) and circuit. Refer toEC-217.
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace.
2. GO TO 4.
18.CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of a problem, but
this is the rarely the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer toEC-48, "
NATS
(Nissan Anti-theft System)".
>> GO TO 4. M/T: 14±5°BTDC
A/T: 16±5°BTDC (in "P" or "N" position)
EC-94
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TROUBLE DIAGNOSIS
ACTIVE TEST MODE
Test Item
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer toEC-40, "SYSTEM READINESS TEST (SRT) CODE".
SRT Work Support Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION
lEngine: Return to the original
trouble condition
lChange the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
lHarness and connectors
lFuel injectors
lHeated oxygen sensor 1
IGNITION TIM-
ING
lEngine: Return to the original
trouble condition
lTiming light: Set
lRetard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
lPerform “Idle Air Volume Learn-
ing”.
POWER BAL-
ANCE
lEngine: After warming up, idle
the engine.
lA/C switch “OFF”
lShift lever “N”
lCut off each injector signal one at
a time using CONSULT-II.Engine runs rough or dies.
lHarness and connectors
lCompression
lFuel injectors
lPower transistor
lSpark plugs
lIgnition coils
COOLING FAN
lIgnition switch: ON
lTurn the cooling fan “ON” and
“OFF” with CONSULT-II.Cooling fan moves and stops.
lHarness and connectors
lCooling fan relay
lCooling fan motor
ENG COOLANT
TEMP
lEngine: Return to the original
trouble condition
lChange the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
lHarness and connectors
lEngine coolant temperature sen-
sor
lFuel injectors
FUEL PUMP
RELAY
lIgnition switch: ON (Engine
stopped)
lTurn the fuel pump relay “ON”
and “OFF” using CONSULT-II
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.lHarness and connectors
lFuel pump relay
PURG VOL
CONT/V
lEngine: After warming up, run
engine at 1,500 rpm.
lChange the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.Engine speed changes according to
the opening percent.lHarness and connectors
lSolenoid valve
V/T ASSIGN
ANGLE
lEngine: Return to the original
trouble condition
lChange intake valve timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
lHarness and connectors
lIntake valve timing control sole-
noid valve
EC-98
[QR (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
lSpecification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data in
spite of the ignition timing not being adjusted to the specification data. This IGN TIMING monitors the data calculated by the ECM
according to the signals input from the camshaft position sensor and other ignition timing related sensors.
lIf the real-time diagnosis results are NG and the on board diagnostic system results are OK when diagnosing the mass air flow sen-
sor, first check to see if the fuel pump control circuit is normal.
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED
lTachometer: Connect
lRun engine and compare tachometer indication with the CONSULT-II
value.Almost the same speed as the
CONSULT-II value.
MAS A/F SE-B1
lEngine: After warming up
lAir conditioner switch: OFF
lShift lever: N
lNo-loadIdle Approx. 1.0 - 1.5V
2,500 rpm Approx. 1.6 - 2.0V
B/FUEL SCHDL
lEngine: After warming up
lShift lever: N
lAir conditioner switch: OFF
lNo-loadIdle 2.5 - 3.5 msec
2,000 rpm 2.5 - 3.5 msec
A/F ALPHA-B1
lEngine: After warming upMaintaining engine speed at 2,000
rpm54% - 155%
COOLAN TEMP/S
lEngine: After warming up More than 70°C(158°F)
HO2S1 (B1)
lEngine: After warming upMaintaining engine speed at 2,000
rpm0 - 0.3V¨Approx. 0.6 - 1.0V
HO2S2 (B1)
lEngine: After warming upRevving engine from idle to 3,000
rpm quickly.0 - 0.3V¨Approx. 0.6 - 1.0V
HO2S1 MNTR (B1)
lEngine: After warming upMaintaining engine speed at 2,000
rpmLEAN¨RICH
Changes more than 5 times dur-
ing 10 seconds.
HO2S2 MNTR (B1)
lEngine: After warming upRevving engine from idle to 3,000
rpm quickly.LEAN¨RICH
VEH SPEED SE
lTurn drive wheels and compare speedometer indication with the CON-
SULT-II value.Almost the same speed as the
CONSULT-II value
BATTERY VOLT
lIgnition switch: ON (Engine stopped) 11 - 14V
ACCEL SEN1
lIgnition switch: ON
(engine stopped)Accelerator pedal: Fully released 0.41 - 0.71V
Accelerator pedal: Fully depressed More than 3.9V
ACCEL SEN2
lIgnition switch: ON
(engine stopped)Accelerator pedal: Fully released 0.15 - 0.97V
Accelerator pedal: Fully depressed More than 3.8V
THRTL SEN1
THRTL SEN2
lIgnition switch: ON
(Engine stopped)Accelerator pedal: Fully released More than 0.36V
lShift lever:
D (A/T model)
1st (M/T model)Accelerator pedal: Fully depressed Less than 4.75V
START SIGNAL
lIgnition switch: ON®START®ON OFF®ON®OFF
CLSD THL POS
lIgnition switch: ONAccelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
AIR COND SIG
lEngine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
P/N POSI SW
lIgnition switch: ONShift lever:
P or N (A/T model)
Neutral (M/T model)ON
Shift lever: Except above OFF
EC-194
[QR (WITH EURO-OBD)]
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
PFP:16600
On Board Diagnosis LogicEBS00B5A
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensor 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and light up the MI (2 trip detection logic).
DTC Confirmation ProcedureEBS00B5B
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 CONSUTL-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Turn ignition switch “ON” and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0171 should be detected at this stage, if a
malfunction exists. If so, go toEC-197, "
Diagnostic Procedure".
7. If it is difficult to start engine at step 6, the fuel injection system
has a malfunction, too.
8. Crank engine while depressing accelerator pedal. If engine
starts, go toEC-197, "
Diagnostic Procedure". If engine does not
start, check exhaust and intake air leak visually.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
Sensor Input Signal to ECMECM
functionActuator
Heated oxygen sensors 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injec-
tion controlFuel injectors
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0171
0171Fuel injection system
too lean
lFuel injection system does not operate properly.
lThe amount of mixture ratio compensation is too
large.
(The mixture ratio is too lean.)
lIntake air leaks
lHeated oxygen sensor 1
lInjectors
lExhaust gas leaks
lIncorrect fuel pressure
lLack of fuel
lMass air flow sensor
lIncorrect PCV hose connection
SEF215Z
EC-200
[QR (WITH EURO-OBD)]
DTC P0172 FUEL INJECTION SYSTEM FUNCTION
DTC P0172 FUEL INJECTION SYSTEM FUNCTION
PFP:16600
On Board Diagnosis LogicEBS00B5E
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and light up the MI (2 trip detection logic).
DTC Confirmation ProcedureEBS00B5F
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
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Turn ignition switch “ON” and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0172 should be detected at this stage, if a
malfunction exists. If so, go toEC-203, "
Diagnostic Procedure".
7. If it is difficult to start engine at step 6, the fuel injection system
has a malfunction, too.
8. Crank engine while depressing accelerator pedal.
If engine starts, go toEC-203, "
Diagnostic Procedure". If engine
does not start, remove ignition plugs and check for fouling, etc.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
Sensor Input Signal to ECMECM
functionActuator
Heated oxygen sensors 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injec-
tion controlFuel injectors
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0172
0172Fuel injection system
too rich
lFuel injection system does not operate properly.
lThe amount of mixture ratio compensation is too
large.
(The mixture ratio is too rich.)
lHeated oxygen sensor 1
lInjectors
lExhaust gas leaks
lIncorrect fuel pressure
lMass air flow sensor
SEF215Z