2001 NISSAN PICK-UP engine coolant

3 CHECK COOLING FAN OPERATION
Without CONSULT-II
1. Turn ignition switch ªOFFº.
2. Disconnect engine coolant temperature sensor harness connector.
3. Connect 150Wresistor to engine coolant temperature sensor harness connector.
4. Restart engine and make sure that cooling fan operates.
SEC636CA
OK or NG
OKcGO TO 13.
NGcGO TO 4.
DTC 0208 OVER HEATYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3494

16 CHECK THERMOSTAT
1. Remove thermostat.
2. Check valve seating condition at normal room temperatures.
It should seat tightly.
3. Check valve opening temperature and valve lift.
SLC343
Valve opening temperature:
82ÉC (180ÉF) [standard]
Valve lift:
More than 10 mm/95ÉC (0.394 in/203ÉF)
4. Check if valve is closed at 5ÉC (9ÉF) below valve opening temperature. For details, refer to LC section, ªThermostatº.
OK or NG
OKcGO TO 17.
NGcReplace thermostat.
17 CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Remove engine coolant temperature sensor.
2. Check resistance between engine coolant temperature sensor terminals 1 and 2 as shown in the figure.
SEF304X
OK or NG
OKcGO TO 18.
NGcReplace engine coolant temperature sensor.
DTC 0208 OVER HEATYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3499

18 CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to ªMAIN 12 CAUSES OF OVERHEATINGº, EC-3501.
cINSPECTION END
Main 12 Causes of Overheating
Engine Step Inspection item Equipment Standard Reference page
OFF 1+Blocked radiator
+Blocked condenser
+Blocked radiator grille
+Blocked bumper+Visual No blocking Ð
2+Coolant mixture+Coolant tester 30 - 50% coolant mixture See ªRECOMMENDED
FLUIDS AND LUBRI-
CANTSº in MA section.
3+Coolant level+Visual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee ªChanging Engine
Coolantº, ªENGINE MAIN-
TENANCEº in MA sec-
tion.
4+Radiator cap+Pressure tester 78 - 98 kPa
(0.78 - 0.98 bar, 0.8 - 1.0
kg/cm
2, 11 - 14 psi)
59 - 98 kPa (0.59 - 0.98
bar, 0.6 - 1.0 kg/cm
2,
9 - 14 psi) (Limit)See ªSystem Checkº,
ªENGINE COOLING SYS-
TEMº in LC section.
ON*2 5+Coolant leaks+Visual No leaks See ªSystem Checkº,
ªENGINE COOLING SYS-
TEMº in LC section.
ON*2 6+Thermostat+Touch the upper and
lower radiator hosesBoth hoses should be hot. See ªThermostatº and
ªRadiatorº, ªENGINE
COOLING SYSTEMº in
LC section.
ON*1 7+Cooling fan+Visual Operating See ªDTC 0208 OVER
HEATº, EC-3489.
OFF 8+Combustion gas leak+Color checker chemical
tester 4 gas analyzerNegative Ð
ON*3 9+Coolant temperature
gauge+Visual Gauge less than 3/4
when drivingÐ
+Coolant overflow to res-
ervoir tank+Visual No overflow during driving
and idlingSee ªChanging Engine
Coolantº, ªENGINE MAIN-
TENANCEº in MA sec-
tion.
OFF*4 10+Coolant return from res-
ervoir tank to radiator+Visual Should be initial level in
reservoir tankSee ªENGINE MAINTE-
NANCEº in MA section.
OFF 11+Cylinder head+Straight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See ªInspectionº, ªCYLIN-
DER HEADº in EM sec-
tion.
12+Cylinder block and pis-
tons+Visual No scuffing on cylinder
walls or pistonSee ªInspectionº, ªCYLIN-
DER BLOCKº in EM sec-
tion.
*1: Engine running at idle.
*2: Engine running at 3,000 rpm for 10 minutes.
*3: Drive at 90 km/h (55 MPH) for 30 minutes and then let idle for 10 minutes.
*4: After 60 minutes of cool down time.
For more information, refer to ªOVERHEATING CAUSE ANALYSISº in LC section.
DTC 0208 OVER HEATYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3500

Description
SYSTEM DESCRIPTION
Sensor Input Signal to ECM ECM Function Actuator
Electronic controlled fuel injection pump Fuel injection signal
EGR volume
controlEGR volume control valve Crankshaft position sensor (TDC) Engine speed
Vehicle speed sensor Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Accelerator position sensor Accelerator position
Battery Battery voltage
Air conditioner switch Air conditioner operation
PNP switch Park/Neutral position signal
Barometric pressure sensor (Built into
ECM)Barometric pressure
This system controls flow rate of EGR led from exhaust manifold
to intake manifold. The opening of the EGR by-pass passage in
the EGR volume control valve changes to control the flow rate.
A built-in step motor moves the valve in steps corresponding to
the ECM output pulses. The opening of the valve varies for opti-
mum engine control. The optimum value stored in the ECM is
determined by considering various engine conditions.
The EGR volume control valve remains close under the follow-
ing conditions.
+Engine stopped
+Engine starting
+Low engine coolant temperature
+Excessively high engine coolant temperature
+High engine speed
+Wide open throttle
+Low battery voltage
+Low barometric pressure
SEF908Y
DTC 1003 EGR VOLUME CONT/VYD25DDTi
EC-3605

Description
SYSTEM DESCRIPTION
Sensor Input Signal to ECMECM
FunctionActuator
Crankshaft position
sensor (TDC)Engine speed
Glow
controlGlow lamp,
Glow relay
¯
Glow plugs Engine coolant tem-
perature sensorEngine coolant tem-
perature
When engine coolant temperature is more than approximately
75ÉC (167ÉF), the glow relay turns off, inactivating the quick-glow
control until coolant temperature drops below approximately
55ÉC (131ÉF).
When coolant temperature is lower than approximately 75ÉC
(167ÉF):
+Ignition switch ON
After ignition switch has turned to ON, the glow relay turns
ON for a certain period of time in relation to engine coolant
temperature, allowing current to flow through glow plug.
+Cranking
The glow relay turns ON, allowing current to flow through
glow plug.
+Starting
After engine has started, current continues to flow through
glow plug (after-glow mode) for a certain period in relation to
engine coolant temperature.
When engine speed exceeds approximately 4,800 rpm, cur-
rent flow through glow plug is interrupted.
The glow indicator lamp turns ON for a certain period of time in
relation to engine coolant temperature at the time glow relay is
turned ON.
COMPONENT DESCRIPTION
Glow plug
+The glow plug is provided with a ceramic heating element to
obtain a high-temperature resistance. It glows in response to
a signal sent from the ECM, allowing current to flow through
the glow plug via the glow relay.
SEF376Y
GLOW CONTROL SYSTEMYD25DDTi
EC-3621

Component Description
The heat up switch is located on the lower side of the instrument
panel. This switch is used to speed up the heater's operation
when the engine is cold.
When the ECM received the heat up switch ªONº signal, the
ECM increases the engine idle speed to 1,100 to 1,200 rpm to
warm up engine quickly.
This system works when all conditions listed below are met.
Heat up switch ON
Engine coolant temperature Below 105ÉC (221ÉF)
Shift lever ªPº or ªNº
Accelerator pedal Fully released
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
WARM UP SW+Ignition switch: ONHeat up switch: ON ON
Heat up switch: OFF OFF
ECM Terminals and Reference Value
Specification 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 damage the
ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
59 BR/R Heat up switchIgnition switch ªONº
Heat up switch is ªOFFº.0V
Ignition switch ªONº
Heat up switch is ªONº.BATTERY VOLTAGE
(11 - 14V)
SEC235D
HEAT UP SWITCHYD25DDTi
EC-3638

General Specifications
Unit: rpm
EngineYD25DDTi
Idle speed750 25
Maximum engine speed4,900
Injection Pump Numbers
Engine Part number
YD25DDTi 16700 VK500
Injection Nozzle
Unit: kPa (bar, kg/cm2, psi)
Initial injection pressureUsed 18,500 - 19,500 (185 - 195, 189 - 199, 2,682 - 2,828)
New 19,500 - 20,500 (195 - 205, 199 - 209, 2,828 - 2,973)
Limit 16,200 (162, 165, 2,349)
Engine Coolant Temperature Sensor
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.0
90 (194) 0.236 - 0.260
Intake Air Temperature Sensor
Intake air temperature ÉC (ÉF)Resistance kW
20 (68)2.1 - 2.9
80 (176)0.27 - 0.38
Crankshaft Position Sensor (TDC)
Resistance [at 20ÉC (68ÉF)]W495 - 605
Glow Plug
Resistance [at 20ÉC (68ÉF)]WApproximately 0.8
Accelerator Position Sensor
Throttle valve conditionsVoltage (at normal operating temperature, engine is not running, ignition
SW ON)
Accelerator pedal fully released (A) 0.29 - 0.79V
Partially openBetween (A) - (B)
Accelerator pedal fully depressed (B) 3.48 - 4.64V
EGR Volume Control Valve
Resistance [at 20ÉC (68ÉF)]W13-17
SERVICE DATA AND SPECIFICATIONS (SDS)YD25DDTi
EC-3650

Bulb Replacement
The headlamp is a semi-sealed beam type which uses a replace-
able halogen bulb. The bulb can be replaced from the engine
compartment side without removing the headlamp body.
+Grasp only the plastic base when handling the bulb.
Never touch the glass envelope.
1. Disconnect the battery cable.
2. Disconnect the harness connector from the back side of the
bulb.
3. Pull off the rubber cap.
4. Push and raise retaining pin to loosen it.
5. Remove the headlamp bulb carefully. Do not shake or rotate
the bulb when removing it.
6. Install in the reverse order of removal.
CAUTION:
Do not leave headlamp reflector without bulb for a long
period of time. Dust, moisture, smoke, etc. entering head-
lamp body may affect the performance of the headlamp.
Remove headlamp bulb from the headlamp reflector just
before a replacement bulb is installed.
Aiming Adjustment
When performing headlamp aiming adjustment, use an aiming
machine, aiming wall screen or headlamp tester. Aimers should
be in good repair, calibrated and operated in accordance with
respective operation manuals.
If any aimer is not available, aiming adjustment can be done as
follows:
For details, refer to the regulations in your own country.
a. Keep all tires inflated to correct pressures.
b. Place vehicle and tester on one and same flat surface.
c. See that there is no-load in vehicle (coolant, engine oil
filled up to correct level and full fuel tank) other than the
driver (or equivalent weight placed in driver's position).
CAUTION:
Be sure aiming switch is set to ª0º when performing aiming
adjustment on vehicles equipped with headlamp aiming
control.
GEL452A
SEL596Y
SEL597Y
HEADLAMP Ð Conventional Type Ð
EL-3027