2001 NISSAN ALMERA N16 coolant sensor

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-123

SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Crankshaft position sensor (POS)
circuit22EC-272
Camshaft position sensor
(PHASE) circuit3 2 3 EC-278
Mass air flow sensor circuit11222 22 2EC-152
Heated oxygen sensor 1 (front)
circuit1232 22 2EC-176,
183
Engine coolant temperature sen-
sor circuit112323223 2EC-163,
165
Throttle position sensor circuit 1 222222 2EC-168
Incorrect throttle position sensor
adjustment31 11111 1EC-98
Vehicle speed sensor circuit 2 3 3 3 EC-309
Knock sensor circuit 2 3 EC-268
ECM 22333333333EC-327,
123
Start signal circuit 2EC-461
PNP switch circuit 3 3 3 3 3 EC-364
Power steering oil pressure switch
circuit2 3 3 EC-471
Electrical load signal circuit 3 3 EC-480
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
Symptom Matrix Chart (Cont'd)
EC-125

MONITOR ITEM CONDITION SPECIFICATION
COOLING FAN+After warming up engine, idle
the engine.
+Air conditioner switch: OFFEngine coolant temperature is 99ÉC
(210ÉF) or lessOFF
Engine coolant temperature is 100ÉC
(212ÉF) or moreON
HO2S1 HTR (B1)+Engine speed: Below 3,200 rpm ON
+Engine speed: Above 3,200 rpm OFF
HO2S2 HTR (B1)+Engine speedBelow 3,600 rpm [After driving for 2
minutes at a speed of 70 km/h (43
MPH) or more]ON
Above 3,600 rpm OFF
+Ignition switch ON (Engine stopped) OFF
TRVL AFTER MI+Ignition switch: ONVehicle has traveled after MI has
turned ON.0 - 65,535 km
(0 - 40,723 mile)
*: If so equipped
Major Sensor Reference Graph in Data Monitor
Mode
NJEC0043The following are the major sensor reference graphs in ªDATA MONITORº mode.
THRTL POS SEN, ABSOL TH´P/S, CLSD THL/P SWNJEC0043S01Below is the data for ªTHRTL POS SENº, ªABSOL TH´P/Sº and ªCLSD THL/P SWº when depressing the
accelerator pedal with the ignition switch ªONº.
The signal of ªTHRTL POS SENº and ªABSOL TH´P/Sº should rise gradually without any intermittent drop or
rise after ªCLSD THL/P SWº is changed from ªONº to ªOFFº.
SEF240Y
ENG SPEED, MAS A/F SE-B1, THRTL POS SEN, HO2S2 (B1), HO2S1 (B1), INJ PULSE-B1NJEC0043S02Below is the data for ªENG SPEEDº, ªMAS A/F SE-B1º, ªTHRTL POS SENº, ªHO2S2 (B1)º, ªHO2S1 (B1)º and
ªINJ PULSE-B1º when revving engine quickly up to 4,800 rpm under no load after warming up engine to nor-
mal operating temperature.
Each value is for reference, the exact value may vary.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
CONSULT-II Reference Value in Data Monitor Mode (Cont'd)
EC-130

TERMI-
NAL
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
62 WHeated oxygen sensor 1
(front)[Engine is running]
+Warm-up condition
+Engine speed is 2,000 rpm0 - Approximately 0.7V
SEF008W
63 LHeated oxygen sensor 2
(rear)[Engine is running]
+After warming up to normal operating tem-
perature and engine speed is 3,000 rpm0 - Approximately 1.0V
64 Y/BIntake air temperature
sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with
intake air temperature
66
75R
RCamshaft position sen-
sor (PHASE)[Engine is running]
+Warm-up condition
+Idle speed2.0 - 3.0V
SEF977W
[Engine is running]
+Engine speed is 2,000 rpm2.0 - 3.0V
SEF978W
67 W/LPower supply for ECM
(Back-up)[Ignition switch ªOFFº]BATTERY VOLTAGE
(11 - 14V)
70 BR/WEngine coolant tempera-
ture sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with
engine coolant temperature
71 GYThrottle position sensor
signal output[Engine is running]
+Warm-up condition
+Accelerator pedal fully releasedApproximately 0.4V
[Ignition switch ªONº]
+Accelerator pedal fully depressedApproximately 4V
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
ECM Terminals and Reference Value (Cont'd)
EC-137

DescriptionNJEC1265The specification (SP) value indicates the tolerance of the value that is displayed in ªDATA MONITOR (SPEC)º
mode of CONSULT-II during normal operation of the Engine Control System. When the value in ªDATA MONI-
TOR (SPEC)º mode is within the SP value, the Engine Control System is confirmed OK. When the value in
ªDATA MONITOR (SPEC)º mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
+B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)
+A/F ALPHA-B1 (The mean value of air-fuel ratio feedback correction factor per cycle)
+MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionNJEC1266+Vehicle driven distance: More than 5,000 km (3,017 miles)
+Barometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm2, 14.25 - 15.12 psi)
+Atmospheric temperature: 20 - 30ÉC (68 - 86ÉF)
+Engine coolant temperature: 75 - 95ÉC (167 - 203ÉF)
+Transmission: Warmed-up*1
+Electrical load: Not applied*2
+Engine speed: Idle
*1: For A/T or CVT models, after the engine is warmed up to normal operating temperature, drive vehicle until
ªFLUID TEMP SEº (A/T or CVT fluid temperature sensor signal) indicates less than 0.9V. For M/T models, drive
vehicle for 5 minutes after the engine is warmed up to normal operating temperature.
*2: Rear window defogger switch, air conditioner switch, lighting switch are ªOFFº. Cooling fans are not oper-
ating. Steering wheel is straight ahead.
SEF601Z
Inspection ProcedureNJEC1267NOTE:
Perform ªDATA MONITOR (SPEC)º mode in maximum scale dis-
play.
1. Perform ªBasic Inspectionº, EC-98.
2. Confirm that the testing conditions indicated above are met.
3. Select ªB/FUEL SCHDLº, ªA/F ALPHA-B1º and ªMAS A/F
SE-B1º in ªDATA MONITOR (SPEC)º mode with CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to ªDiagnostic Procedureº, EC-141.
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUEQG
Description
EC-140

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-163

Fail-safe ModeNJEC0566
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
ªONº or ªSTARTº.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided (CONSULT-II
display)
Just as ignition switch is turned 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)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates
while the engine is running.
SEF013Y
DTC Confirmation ProcedureNJEC0075NOTE:
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) Turn ignition switch ªONº.
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-166 .
With GST
Follow the procedure ªWith CONSULT-IIº above.
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR (ECTS)
(CIRCUIT)
QG
Fail-safe Mode
EC-164

Wiring DiagramNJEC0076
YEC965
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR (ECTS)
(CIRCUIT)
QG
Wiring Diagram
EC-165