2001 NISSAN ALMERA lights

IntroductionNJEC0029MODELS WITH EURO-OBD SYSTEMNJEC0029S01The ECM has an on board diagnostic system which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-related diagnostic information including:
Diagnostic Trouble Code (DTC) Mode 3 of ISO 15031-5
Freeze Frame data Mode 2 of ISO 15031-5
System Readiness Test (SRT) code Mode 1 of ISO 15031-5
1st Trip Diagnostic Trouble Code (1st Trip DTC) Mode 7 of ISO 15031-5
1st Trip Freeze Frame data
Test values and Test limits Mode 6 of ISO 15031-5
Calibration ID Mode 9 of ISO 15031-5
The above information can be checked using procedures listed in the table below.
X: Applicable Ð: Not applicable
DTC 1st trip DTCFreeze Frame
data1st trip Freeze
Frame dataSRT code Test value
ECM*3 X X*1ÐÐÐÐ
CONSULT-IIXXXXXÐ
GST X X*2 X Ð X X
*1: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
*2: 1st trip DTCs for self-diagnoses concerning SRT items cannot be shown on the GST display.
*3: In diagnostic test mode II (Self-diagnostic results), DTC is displayed on MI. DTC uses a set of four digit numbers. (If so equipped)
The malfunction indicator (MI) on the instrument panel lights up when the same malfunction is detected in two
consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode. (Refer to EC-154.)
MODELS WITHOUT EURO-OBD SYSTEMNJEC0029S02The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-related diagnostic information including:
Diagnostic Trouble Code (DTC)
Freeze Frame data
1st Trip Diagnostic Trouble Code (1st Trip DTC)
1st Trip Freeze Frame data
The above information can be checked using procedures listed in the table below.
X: Applicable Ð: Not applicable
DTC 1st trip DTC Freeze Frame data1st trip Freeze Frame
data
CONSULT-II X X X X
ECM*1 X X*2 Ð Ð
*1: In diagnostic test mode II (Self-diagnostic results), (1st trip) DTC is displayed on the MI by a set of four digit numbers.
*2: When the DTC and the 1st trip DTC appear on the display simultaneously, it is difficult to clearly distinguish one from the other.
Two Trip Detection LogicNJEC0030MODELS WITH EURO-OBD SYSTEMNJEC0030S01When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in
the ECM memory. The MI will not light up at this stage <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, and the MI lights up. The MI lights up at the same time when the DTC is stored <2nd
trip>.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
Introduction
EC-59

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-154.)Ð X Ð Ð X*1 Ð X*1 Ð
Except above Ð ÐÐXÐX XÐ
*1: Except ªECMº.
MODELS WITHOUT EURO-OBD SYSTEMNJEC0030S02When 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-154), the DTC is stored in the ECM memory even in the 1st trip.
Emission-related Diagnostic InformationNJEC0031MODELS WITH EURO-OBD SYSTEMNJEC0031S01DTC and 1st Trip DTCNJEC0031S0101The 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-70.
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-98. 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 DESCRIPTIONQG
Two Trip Detection Logic (Cont'd)
EC-60

SEF543X
NATS (Nissan Anti-theft System)NJEC0591+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
registration 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 procedure of NATS initialization and NATS
ignition key ID registration, refer to CONSULT-II operation
manual, NATS.
Malfunction Indicator (MI)
DESCRIPTIONNJEC0032
SAT652J
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.
+If the MI does not light up, refer to EL-184, ªWARNING LAMPSº or see EC-591.
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 FunctionNJEC0032S01The on board diagnostic system has the following four functions.
Diagnostic Test Mode I
1. BULB CHECK:
This function checks the MI bulb for damage (blown, open circuit, etc.).
If the MI does not come on, check MI circuit and ECM test mode selector. (See the following page.)
2. MALFUNCTION WARNING:
MI Condition
ON When the malfunction is detected or the ECM's CPU is malfunctioning.
OFF No malfunction.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
NATS (Nissan Anti-theft System)
EC-74

Fail-safe Chart=NJEC0040The ECM enters fail-safe mode if any of the following malfunctions is detected due to the open or short cir-
cuit. When the ECM enters the fail-safe mode, the MI illuminates.
DTC No.
Detected items Engine operating condition in fail-safe mode CON-
SULT-II
GSTECM*1
P0100 0100 Mass air flow sensor
circuitEngine speed will not rise more than 2,400 rpm due to the fuel cut.
P0115 0115 Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time
after turning ignition switch ªONº or ªSTARTº.
CONSULT-II displays the engine coolant temperature decided by ECM.
The radiator fan operates.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or Start40ÉC (104ÉF)
More than approx. 4 minutes
after ignition ON or Start80ÉC (176ÉF)
Except as shown above40 - 80ÉC (104 - 176ÉF)
(Depends on the time)
P0120 0120 Throttle position sensor
circuitThrottle position will be determined based on the injected fuel amount and
the engine speed. Therefore, acceleration will be poor.
Condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration
Unable to
access
ECMUnable to
access
Diagnostic
Test Mode
IIECMECM fail-safe activating condition
The computing function of the ECM was judged to be malfunctioning.
When the fail-safe system activates (i.e., if the ECM detects a malfunction
condition in the CPU of ECM), the MI on the instrument panel lights to warn
the driver.
However it is not possible to access ECM and DTC cannot be confirmed.
Engine control with fail-safe
When ECM fail-safe is operating, fuel injection, ignition timing, fuel pump
operation and IACV-AAC valve operation are controlled under certain limita-
tions.
ECM fail-safe operation
Engine speedEngine speed will not rise more than
3,000 rpm
Fuel injectionSimultaneous multiport fuel injection sys-
tem
Ignition timing Ignition timing is fixed at the preset value
Fuel pumpFuel pump relay is ªONº when engine is
running and ªOFFº when engine stalls
IACV-AAC valve Full open
Cooling fansCooling fan relay ªONº (High speed condi-
tion) when engine is running, and ªOFFº
when engine stalls.
Replace ECM, if ECM fail-safe condition is confirmed.
*: In Diagnostic Test Mode II (Self-diagnostic results) (If so equipped)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
Fail-safe Chart
EC-154

SEF987W
Component DescriptionNJEC0050The mass air flow sensor is placed in the stream of intake air. It
measures the intake flow rate by measuring a part of the entire
intake flow. It consists of a hot wire that is supplied with electric
current from the ECM. The temperature of the hot wire is controlled
by the ECM a certain amount. The heat generated by the hot wire
is reduced as the intake air flows around it. The more air, the
greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot wire as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0051Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1+Engine: After warming up
+Air conditioner switch: ªOFFº
+Shift lever: ªNº
+No-loadIdle 1.0 - 1.7V
2,500 rpm 1.5 - 2.1V
MASS AIRFLOW+Engine: After warming up
+Air conditioner switch: ªOFFº
+Shift lever: ªNº
+No-loadIdle 1.0 - 4.0 g´m/s
2,500 rpm 5.0 - 10.0 g´m/s
ECM Terminals and Reference ValueNJEC0052Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
61 G Mass air flow sensor[Engine is running]
+Warm-up condition
+Idle speed1.0 - 1.7V
[Engine is running]
+Warm-up condition
+Engine speed is 2,500 rpm1.5 - 2.1V
73 BMass air flow sensor
ground[Engine is running]
+Warm-up condition
+Idle speedApproximately 0V
On Board Diagnosis LogicNJEC0053
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0100
0100A) An excessively high voltage from the sensor is sent
to ECM when engine is not running.+Harness or connectors
(The sensor circuit is open or shorted.)
+Mass air flow sensor
B) An excessively low voltage from the sensor is sent
to ECM* when engine is running.+Harness or connectors
(The sensor circuit is open or shorted.)
+Intake air leaks
+Mass air flow sensor
*: When this malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG
Component Description
EC-187

SEF594K
Component DescriptionNJEC0072The engine coolant temperature sensor is used to detect the
engine coolant temperature. The sensor modifies a voltage signal
from the ECM. The modified signal returns to the ECM as the
engine coolant temperature input. The sensor uses a thermistor
which is sensitive to the change in temperature. The electrical
resistance of the thermistor decreases as temperature increases.
SEF012P

Engine coolant temperature
ÉC (ÉF)Voltage*
VResistance
kW
þ10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
*: These data are reference values and are measured between ECM terminal 70
(Engine coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0073
MONITOR ITEM CONDITION SPECIFICATION
COOLAN TEMP/S+Engine: After warming up More than 70ÉC (158ÉF)
On Board Diagnosis LogicNJEC0074
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0115
0115+An excessively high or low voltage from the sensor is
sent to ECM.*+Harness or connectors
(The sensor circuit is open or shorted.)
+Engine coolant temperature sensor
*: When this malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR
(ECTS) (CIRCUIT)
QG
Component Description
EC-201

ECM Terminals and Reference Value=NJEC0081Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
58 B Sensors' ground[Engine is running]
+Warm up condition
+Idle speedApproximately 0V
92 Y Throttle position sensor[Engine is running]
+Accelerator pedal fully released0.15 - 0.85V
[Ignition switch ªONº]
+Accelerator pedal fully depressed3.5 - 4.7V
111 R Sensors' power supply[Ignition switch ªONº]Approximately 5V
On Board Diagnosis LogicNJEC0082
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0120
0120An excessively low or high voltage from the sensor is
sent to ECM* while driving.+Harness or connectors
(The throttle position sensor circuit is open or
shorted.)
+Throttle position sensor
*: When this malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
Fail-safe ModeNJEC0567
Detected items Engine operating condition in fail-safe mode
Throttle position sensor
circuitThrottle position will be determined based on the injected fuel amount and the engine speed.
Therefore, acceleration will be poor.
Condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration
DTC Confirmation ProcedureNJEC0083NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
+Before performing the following procedure, confirm that
battery voltage is more than 10V at idle.
+This test may be conducted with the drive wheels lifted in
DTC P0120 THROTTLE POSITION SENSORQG
ECM Terminals and Reference Value
EC-208

On Board Diagnosis LogicNJEC0188With 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 (front).
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 lights up the MIL (2 trip detection logic).
Sensor Input Signal to ECMECM func-
tionActuator
Heated oxygen sensor 1 (front)Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injec-
tion & mix-
ture ratio
controlInjectors
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0171
0171+Fuel injection system does not operate properly.
+The amount of mixture ratio compensation is too large.
(The mixture ratio is too lean.)+Intake air leaks
+Heated oxygen sensor 1 (front)
+Injectors
+Exhaust gas leaks
+Incorrect fuel pressure
+Lack of fuel
+Mass air flow sensor
SEF215Z
SEF058Y
DTC Confirmation ProcedureNJEC0189NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds.
3) Turn ignition switch ªONº and select ªSELF-LEARN CON-
TROLº in ªWORK SUPPORTº mode with CONSULT-II.
4) Clear the self-learning control coefficient by touching ªSTARTº.
5) Select ªDATA MONITORº 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 to ªDiagnostic Procedureº,
EC-301.
7) If it is difficult to start engine at step 6, the fuel injection sys-
tem has a malfunction.
8) Crank engine while depressing accelerator pedal. If engine
starts, go to ªDiagnostic Procedureº, EC-301. If engine does
not start, visually check for exhaust and intake air leak.
JEF105Y
With GST
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds.
3) Disconnect mass air flow sensor harness connector. Then
restart and run engine for at least 3 seconds at idle speed.
4) Stop engine and reconnect mass air flow sensor harness con-
nector.
5) Select ªMODE 7º with GST. Make sure 1st trip DTC P0100 is
detected.
6) Select ªMODE 4º with GST and erase the 1st trip DTC P0100.
DTC P0171 FUEL INJECTION SYSTEM FUNCTION (LEAN SIDE)QG
On Board Diagnosis Logic
EC-297