sensor NISSAN PRIMERA 1999 Electronic Repair Manual

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK POWER SUPPLY.
1. Turn ignition switch to ªLOCKº position.
2. Disconnect mass air flow sensor harness
connector.
3. Turn ignition switch to ªONº position.
4. Check voltage between mass air flow
sensor connector terminal
p2and
ground.
Voltage: Battery positive voltage
OK
ENG
Repair harness or connec-
tors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch to ªLOCKº position.
2. Disconnect ECM harness connector.
3. Check harness continuity between mass
air flow sensor connector terminal
p3and ECM connector terminal218.
Continuity should exist.
If OK, check harness for short-circuit.
OK
ENG
Repair harness or connec-
tors.
CHECK INPUT SIGNAL CIRCUIT.
Check harness continuity between mass air
flow sensor connector terminal
p4and
ECM connector terminal223, mass air
flow sensor connector terminal
p5and
ECM connector terminal224.
Continuity should exist.
If OK, check harness for short.
OK
ENG
Repair harness or connec-
tors.
CHECK COMPONENT
(Mass air flow sensor).
Refer to ªCOMPONENT INSPECTIONº on
next page.
OK
ENG
Replace mass air flow sen-
sor.
Disconnect and reconnect harness connec-
tors in the circuits. Then retest.
Trouble is not fixed.
Check ECM pin terminals for damage or the
connection of ECM harness connector.
INSPECTION END
NEF788 Mass air flow sensor harness connector
NEF789
Mass air flow
sensor connector
NEF191A
Mass air
flow sensor
connector
NEF192A
Mass air flow sensor
connector
H
H
H
H
H
H
H
TROUBLE DIAGNOSIS 1CD20T
Mass Air Flow Sensor (MAFS) (Cont'd)
EC-64

COMPONENT INSPECTION
Mass air flow sensor
1. Turn ignition switch to ªONº position.
2. Start engine and warm it up sufficiently.
3. Check voltage between mass air flow sensor connector ter-
minal
p5and ground.
Conditions Voltage V
Ignition switch ªONº position (Engine stopped.)Approximately 1.0
Idle (Engine is warmed-up sufficiently.)1.9 - 2.3
4. If NG, remove mass air flow sensor from air duct. Check hot
film for damage or dust.
NEF792 Mass air flow sensor
connector
NEF669
TROUBLE DIAGNOSIS 1CD20T
Mass Air Flow Sensor (MAFS) (Cont'd)
EC-65

Engine Coolant Temperature (ECT) Sensor
The engine coolant temperature sensor is used to detect the
engine coolant temperature. The sensor modifies a voltage sig-
nal 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
(V)Resistance
(kW)
þ10 (14)4.4 7.0 - 11.4
20 (68)3.5 2.1 - 2.9
50 (122)2.3 0.68 - 1.00
90 (194)1.0 0.236 - 0.260
Malfunction is detected when ...Check Items
(Possible Cause)
lAn excessively high or low voltage from the sensor is
entered to ECM.lHarness or connectors
(The sensor circuit is open or shorted.)
lEngine coolant temperature sensor
DIAGNOSTIC TROUBLE CONFIRMATION
PROCEDURE
1) Turn ignition switch to ªONº position.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 5 seconds.
SEF594K
SEF012P
TROUBLE DIAGNOSIS 2CD20T
EC-66

YEC800
ENGINE COOLANT
TEMPERATURE
SENSOR
: Detectable line for DTC
: Non-detectable line for DTC
ECM
TROUBLE DIAGNOSIS 2CD20T
Engine Coolant Temperature (ECT) Sensor
(Cont'd)
EC-67

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK POWER SUPPLY.
1. Turn ignition switch to ªLOCKº posi-
tion.
2. Disconnect engine coolant tempera-
ture sensor harness connector.
3. Turn ignition switch to ªONº position.
4. Check voltage between engine cool-
ant temperature sensor connector
terminal
p2and ground with CON-
SULT-II or tester.
Voltage:
Approximately 4.9V
OK
ENG
Repair harness or con-
nectors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch to ªLOCKº posi-
tion.
2. Check harness continuity between
engine coolant temperature sensor
connector terminal
p1and engine
ground.
Continuity should exist.
If OK, check harness for short-cir-
cuit.
OK
ENG
Repair harness or con-
nectors.
CHECK COMPONENT
(Engine coolant temperature sensor).
Refer to ªCOMPONENT INSPECTIONº
on next page.
OK
ENG
Replace engine coolant
temperature sensor.
Disconnect and reconnect harness
connectors in the circuit. Then retest.
Trouble is not fixed.
Check ECM pin terminals for damage
and check the connection of ECM har-
ness connector. Reconnect ECM har-
ness connector and retest.
INSPECTION END
NEF401
.RH strut tower
.Engine coolant temperature
sensor harness connector
NEF193A
Engine coolant temperature
sensor connector
SEF542P
Engine coolant temperature
sensor connector
H
H
H
H
H
H
TROUBLE DIAGNOSIS 2CD20T
Engine Coolant Temperature (ECT) Sensor
(Cont'd)
EC-68

COMPONENT INSPECTION
Engine coolant temperature sensor
Check resistance as shown in the figure.
Temperature ÉC (ÉF) Resistance kW
20 (68)2.1 - 2.9
50 (122)0.68 - 1.0
90 (194)0.236 - 0.260
If NG, replace engine coolant temperature sensor.
SEF152P
SEF012P
TROUBLE DIAGNOSIS 2CD20T
Engine Coolant Temperature (ECT) Sensor
(Cont'd)
EC-69

Vehicle Speed Sensor (VSS)
Models with vehicle speed sensor
The vehicle speed sensor is installed in the transaxle. It contains
a pulse generator which provides a vehicle speed signal to the
speedometer. The speedometer then sends a signal to the ECM.
Models without vehicle speed sensor
The ABS actuator and electric unit (control unit) provides a
vehicle speed signal to the speedometer. The speedometer than
sends a signal to the ECM.
Malfunction is detected when ....Check Items
(Possible Cause)
lThe almost 0 km/h (0 mph) signal from vehicle speed sen-
sor or ABS actuator and electric unit (control unit) is sent
to ECM even when vehicle is being driven.Models with vehicle speed sensor
lHarness or connector
(The vehicle speed sensor circuit is open or shorted.)
lVehicle speed sensor
Models without vehicle speed sensor
lHarness or connector
(The ABS actuator and electric unit (control unit) is open or
shorted.)
lABS actuator and electric unit (control unit)
OVERALL FUNCTION CHECK
Use this procedure to check the overall function of the vehicle
speed sensor circuit. During this check, a DTC might not be
confirmed.
1) Jack up drive wheels.
2) Start engine.
3) Read vehicle speed sensor signal in ªDATA MONI-
TORº mode with CONSULT-II.
The vehicle speed on CONSULT-II should be able to
exceed 10 km/h (6 mph) when rotating wheels with
suitable gear position.
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Jack up drive wheels.
2) Start engine.
3) Rotate drive wheel by hand.
4) Check voltage between ECM connector terminal
417and ground with voltage tester.
Voltage should vary between approx. 0 - 0.6V.
AEC110 Vehicle speed
sensor
PEF651U
NEF194A
TROUBLE DIAGNOSIS 3CD20T
EC-70

MODELS BEFORE VIN - P11U0583350
YEC801
BATTERYIGNITION SWITCH
ON or START
FUSE
BLOCK
(J/B)Refer to EL-POWER.
: Dectable line for DTC
: Non-detectable line for DTC
VEHICLE
SPEED
SENSOR COMBINATION
METER
(SPEEDOMETER)
ECM
REFER TO THE FOLLOWING
FUSE BLOCK - Junction Box (J/B)
TROUBLE DIAGNOSIS 3CD20T
Vehicle Speed Sensor (VSS) (Cont'd)
EC-71

MODELS AFTER VIN - P11U0583350
YEC101A
TROUBLE DIAGNOSIS 3CD20T
Vehicle Speed Sensor (VSS) (Cont'd)
EC-72

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK INPUT SIGNAL CIRCUIT.
1. Turn ignition switch to ªLOCKº posi-
tion.
2. Disconnect ECM harness connector
and combination meter harness con-
nector.
3. Check harness continuity between
ECM connector terminal
417and
combination meter connector termi-
nal
p9orp4.
Continuity should exist.
If OK, check harness for short-cir-
cuit.
OK
ENG
Check the following:
lHarness connectors
M50,F104
lHarness for open or
short-circuit between
ECM and combination
meter.
If NG, repair harness or
connectors.
CHECK SPEEDOMETER FUNCTION.
Make sure that speedometer functions
correctly.
OK
ENG
Check the following:
lHarness connectors
M50,F104
lHarness for open or
short-circuit between
combination meter and
vehicle speed sensor
or ABS actuator and
electric unit (control
unit).
If NG, repair harness or
connectors.
Check vehicle speed
sensor or ABS actuator
and electric unit (control
unit) and its circuit.
Refer to EL section.
Disconnect and reconnect harness
connectors in the circuit. Then retest.
Trouble is not fixed.
Check ECM pin terminals for damage
and check the connection of ECM har-
ness connector. Reconnect ECM har-
ness connector and retest.
INSPECTION END
YEC124A
H
H
H
H
H
TROUBLE DIAGNOSIS 3CD20T
Vehicle Speed Sensor (VSS) (Cont'd)
EC-73