NISSAN PRIMERA 1999 Electronic Repair Manual

4 DETECT MALFUNCTIONING PART
Check the following.
IHarness for open or short between ECM and intake air temperature sensor
©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to ªComponent Inspectionº, EC-QG-119.
OK or NG
OK©GO TO 6.
NG©Replace intake air temperature sensor.
6 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-QG-102.
©INSPECTION END
Component InspectionNCEC0071INTAKE AIR TEMPERATURE SENSORNCEC0071S01Check resistance between mass air flow sensor terminal 1 and 3.

Intake air temperature
ÉC (ÉF)Resistance kW
20 (68) 2.1 - 2.9
80 (176) 0.27 - 0.38
If NG, replace mass air flow sensor.
SEF012P
DTC P0110 INTAKE AIR TEMPERATURE SENSORQG16I18DE
Diagnostic Procedure (Cont'd)
EC-119

Component DescriptionNCEC0072The 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.

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 dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0073
MONITOR ITEM CONDITION SPECIFICATION
COOLAN TEMP/SIEngine: After warming up More than 70ÉC (158ÉF)
On Board Diagnosis LogicNCEC0074
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0115
0115IAn excessively high or low voltage from the sensor is
sent to ECM.*IHarness or connectors
(The sensor circuit is open or shorted.)
IEngine coolant temperature sensor
*: 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
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.
SEF594K
SEF012P
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR
(ECTS) (CIRCUIT)QG16I18DE
Component Description
EC-120

DTC Confirmation ProcedureNCEC0075NOTE:
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-
QG-123.
With GST
Follow the procedure ªWith CONSULT-IIº above.
NEF068A
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR
(ECTS) (CIRCUIT)QG16I18DE
DTC Confirmation Procedure
EC-121

Wiring DiagramNCEC0076
YEC261
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR
(ECTS) (CIRCUIT)QG16I18DE
Wiring Diagram
EC-122

Diagnostic ProcedureNCEC0077
1 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect engine coolant temperature sensor harness connector.
SEF999W3. Turn ignition switch ªONº.
4. Check voltage between terminal 2 and ground with CONSULT-II or tester.
SEF997WVoltage: Approximately 5V
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the harness for open or short between ECM and engine coolant temperature sensor.
©Repair harness or connectors.
3 CHECK GROUND CIRCUIT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between engine coolant temperature sensor harness connector terminal 1 and engine ground.
Refer to wiring diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
IHarness for open or short between ECM and engine coolant temperature sensor
©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR
(ECTS) (CIRCUIT)QG16I18DE
Diagnostic Procedure
EC-123

5 CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to ªComponent Inspectionº, EC-QG-124.
OK or NG
OK©GO TO 6.
NG©Replace engine coolant temperature sensor.
6 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-QG-102.
©INSPECTION END
Component InspectionNCEC0078ENGINE COOLANT TEMPERATURE SENSORNCEC0078S01Check resistance as shown in the figure.

Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
If NG, replace engine coolant temperature sensor.
SEF152P
SEF012P
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR
(ECTS) (CIRCUIT)QG16I18DE
Diagnostic Procedure (Cont'd)
EC-124

Component DescriptionNCEC0079The throttle position sensor responds to the accelerator pedal movement. This sensor is a kind of potentiom-
eter which transforms the throttle position into output voltage, and emits the voltage signal to the ECM. In
addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal
to the ECM.
Idle position of the throttle valve is determined by the ECM receiving the signal from the throttle position sen-
sor. This sensor controls engine operation such as fuel cut. On the other hand, the ªWide open and closed
throttle position switchº, which is built into the throttle position sensor unit, is not used for engine control.
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0080Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
THRTL POS SENIEngine: Idle Throttle valve fully closed 0.35 - 0.65V
IIgnition switch: ON
(Engine stopped)Throttle valve fully opened 3.7 - 4.5V
ABSOL TH×P/SIEngine: Idle Throttle valve fully closed 0.0É
IIgnition switch: ON
(Engine stopped)Throttle valve fully opened Approx. 80É
NEF245A Throttle
position
sensor
Output voltage between terminal No. 2 and 3 (V)
Throttle valve opening angle (deg) Output voltage between
terminal No. 2 and 3)Supply voltage: 5V
(Applied between terminal
No. 1 and 3)
DTC P0120 THROTTLE POSITION SENSORQG16I18DE
Component Description
EC-125

ECM Terminals and Reference Value=NCEC0081Specification 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]
IWarm up condition
IIdle speedApproximately 0V
92 Y Throttle position sensor[Engine is running]
IAccelerator pedal fully released0.35 - 0.65V
[Ignition switch ªONº]
IAccelerator pedal fully depressed3.7 - 4.5V
111 G Sensors' power supply[Ignition switch ªONº]Approximately 5V
On Board Diagnosis LogicNCEC0082
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.IHarness or connectors
(The throttle position sensor circuit is open or
shorted.)
IThrottle position sensor
*: 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 Confirmation ProcedureNCEC0083NOTE:
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:
IBefore performing the following procedure, confirm that
battery voltage is more than 10V at idle.
IThis test may be conducted with the drive wheels lifted in
the shop or by driving the vehicle. If a road test is
expected to be easier, it is unnecessary to lift the vehicle.
DTC P0120 THROTTLE POSITION SENSORQG16I18DE
ECM Terminals and Reference Value
EC-126

With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
with CONSULT-II.
2) Start engine and maintain the following conditions for at least
5 consecutive seconds.
VHCL SPEED SE More than 4 km/h (2 MPH)
Selector lever Suitable position except ªNº position
3) If 1st trip DTC is detected, go to ªDiagnostic Procedureº, EC-
QG-129.
With GST
Follow the procedure ªWith CONSULT-IIº above.
PEF651U
DTC P0120 THROTTLE POSITION SENSORQG16I18DE
DTC Confirmation Procedure (Cont'd)
EC-127

Wiring DiagramNCEC0084
YEC064A
DTC P0120 THROTTLE POSITION SENSORQG16I18DE
Wiring Diagram
EC-128