2001 NISSAN PICK-UP light

SEF893J
Component DescriptionNEEC0050The 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
NEEC0051Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ªNº
+No-loadIdle 0.9 - 1.8V
2,500 rpm 1.9 - 2.3V
CAL/LD VALUE+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ªNº
+No-loadIdle 9.5 - 34.0%
2,500 rpm 13.9 - 24.9%
MASS AIRFLOW+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ªNº
+No-loadIdle 0.9 - 5.8 g´m/s
2,500 rpm 7.5 - 13.2 g´m/s
ECM Terminals and Reference ValueNEEC0052Specification 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)
54 L Mass air flow sensor[Engine is running]
+Warm-up condition
+Idle speed0.9 - 1.8V
[Engine is running]
+Warm-up condition
+Engine speed is 2,500 rpm1.9 - 2.3V
55 PMass air flow sensor
ground[Engine is running]
+Warm-up condition
+Idle speedApproximately 0V
On Board Diagnosis LogicNEEC0053
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0101
0101A) A high voltage from the sensor is sent to ECM under
light load driving condition.+Harness or connectors
(The sensor circuit is open or shorted.)
+Mass air flow sensor
DTC P0101 MAF SENSORKA24DE (EURO OBD)
Component Description
EC-3143

DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0101
0101B) A low voltage from the sensor is sent to ECM* under
heavy load driving condition.+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.
FAIL-SAFE MODENEEC0053S01
Detected items Engine operating condition in fail-safe mode
Mass air flow sensor circuitEngine speed will not rise more than 2,400 rpm due to the fuel
cut.
DTC Confirmation ProcedureNEEC0054CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch OFF and wait at least 5 seconds before
conducting the next test.
SEF174Y
PROCEDURE FOR MALFUNCTION ANEEC0054S03NOTE:
If engine will not start or stops soon, wait at least 10 seconds
with engine stopped (Ignition switch ªONº) instead of running
engine at idle speed.
With CONSULT-II
1) Turn ignition switch ON.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and warm it up to normal operating temperature.
4) Run engine for at least 10 seconds at idle speed.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-3147.
With GST
Follow the procedure ªWith CONSULT-IIº.
DTC P0101 MAF SENSORKA24DE (EURO OBD)
On Board Diagnosis Logic
EC-3144

DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0102
0102An 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.
FAIL-SAFE MODENEEC1551S01
Detected items Engine operating condition in fail-safe mode
Mass air flow sensor circuitEngine speed will not rise more than 2,400 rpm due to the fuel
cut.
DTC Confirmation ProcedureNEEC1552CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch OFF and wait at least 5 seconds before
conducting the next test.
SEF058Y
PROCEDURE FOR DTC P0103NEEC1552S01With CONSULT-II
1) Turn ignition switch ON.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 6 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-3155.
If 1st trip DTC is not detected, go to next step.
5) Start engine and let it idle for at least 6 seconds.
6) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-3155.
With GST
Follow the procedure ªWith CONSULT-IIº.
DTC P0102, P0103 MAF SENSORKA24DE (EURO OBD)
On Board Diagnosis Logic
EC-3152

FAIL-SAFE MODENEEC0067S01When the malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
Engine operating condition in fail-safe mode
The ECM functions on the assumption that the intake air temperature is 25ÉC (77ÉF).
DTC Confirmation ProcedureNEEC0068NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch OFF and wait at least 5 seconds before
conducting the next test.
SEF058Y
With CONSULT-II
1) Turn ignition switch ON.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 5 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-3163.
With GST
Follow the procedure ªWith CONSULT-IIº.
DTC P0112, P0113 IAT SENSORKA24DE (EURO OBD)
On Board Diagnosis Logic
EC-3161

On Board Diagnosis LogicNEEC0074
DTC No.Trouble diag-
nosis nameDTC detecting condition Possible cause
P0117
0117Engine cool-
ant tempera-
ture sensor
circuit low
inputAn excessively low voltage from the sensor is sent
to ECM.+Harness or connectors
(The sensor circuit is open or shorted.)
+Engine coolant temperature sensor
P0118
0118Engine cool-
ant tempera-
ture sensor
circuit high
inputAn excessively high voltage from the sensor is sent
to ECM.
FAIL-SAFE MODENEEC0074S01When the malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
Detected items Engine operating condition in fail-safe mode
Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning ignition switch
to ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided (CONSULT-II
display)
Just as ignition switch is turned to ON or Start 40ÉC (104ÉF)
More than approx. 4 minutes after ignition ON or
Start80ÉC (176ÉF)
Except as shown above40 - 80ÉC (104 - 176ÉF)
(Depends on the time)
SEF058Y
DTC Confirmation ProcedureNEEC0075NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch OFF and wait at least 5 seconds before
conducting the next test.
With CONSULT-II
1) Turn ignition switch ON.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 5 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-3168.
With GST
Follow the procedure ªWith CONSULT-IIº.
DTC P0117, P0118 ECT SENSORKA24DE (EURO OBD)
On Board Diagnosis Logic
EC-3166

ECM Terminals and Reference Value=NEEC0081Specification 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)
23 G Throttle position sensor[Ignition switch ON]
+Warm-up condition
+Accelerator pedal fully released0.2 - 0.8V
[Ignition switch ON]
+Accelerator pedal fully depressed3.5 - 4.5V
42 G/B Sensors' power supply[Ignition switch ON]Approximately 5V
43 B Sensors' ground[Engine is running]
+Idle speedApproximately 0V
On Board Diagnosis LogicNEEC0082
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0121
0121A) A high voltage from the sensor is sent to ECM
under light load driving condition.+Harness or connectors
(The throttle position sensor circuit is open or
shorted.)
+Throttle position sensor
+Fuel injector
+Camshaft position sensor
+Mass air flow sensor
B) A low voltage from the sensor is sent to ECM under
heavy load driving condition.+Harness or connectors
(The throttle position sensor circuit is open or
shorted.)
+Intake air leaks
+Throttle position sensor
DTC P0121 TP SENSORKA24DE (EURO OBD)
ECM Terminals and Reference Value
EC-3171

ECM Terminals and Reference Value=NEEC1560Specification 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)
23 G Throttle position sensor[Ignition switch ON]
+Warm-up condition
+Accelerator pedal fully released0.2 - 0.8V
[Ignition switch ON]
+Accelerator pedal fully depressed3.5 - 4.5V
42 G/B Sensors' power supply[Ignition switch ON]Approximately 5V
43 B Sensors' ground[Engine is running]
+Idle speedApproximately 0V
On Board Diagnosis LogicNEEC1561
DTC No.Trouble diagnosis
nameDTC Detecting Condition Possible Cause
P0122
0122Throttle position sen-
sor circuit low inputAn excessively low voltage from the sensor is sent
to ECM.*+Harness or connectors
(The sensor circuit is open or
shorted.)
+Throttle position sensor P0123
0123Throttle position sen-
sor circuit high inputAn excessively high voltage from the sensor is
sent to ECM.*
*: When this malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
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 P0122, P0123 TP SENSORKA24DE (EURO OBD)
ECM Terminals and Reference Value
EC-3183

On Board Diagnosis LogicNEEC0188With 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 lights up the MI (2 trip detection logic).
Sensor Input Signal to ECMECM func-
tionActuator
Heated oxygen sensor 1Density 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
+Injectors
+Exhaust gas leaks
+Incorrect fuel pressure
+Lack of fuel
+Mass air flow sensor
+Incorrect PCV hose connection
SEF215Z
SEF058Y
DTC Confirmation ProcedureNEEC0189NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch OFF and wait at least 5 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 5 seconds.
3) Turn ignition switch ON and select ªSELF-LEARNING CONTº
in ªWORK SUPPORTº mode with CONSULT-II.
4) Clear the self-learning control coefficient by touching ªCLEARº.
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-3240.
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-3240. If engine does
not start, visually check for exhaust and intake air leak.
AEC131A
With GST
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch OFF and wait at least 5 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 DTC P0102 is detected.
6) Select ªMODE 4º with GST and erase the DTC P0102.
7) Start engine again and run it for at least 10 minutes at idle
speed.
DTC P0171 FUEL INJECTION SYSTEM
FUNCTION
KA24DE (EURO OBD)
On Board Diagnosis Logic
EC-3237