engine coolant NISSAN PICK-UP 1998 Owner's Manual

TERMINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC voltage)
4 L/RECCS relay (Self-
shutoff)Engine is running.
Ignition switch ``OFF''
For a few seconds after turning ignition
switch ``OFF''0-1V
Ignition switch ``OFF''
A few seconds passed after turning ignition
switch ``OFF''BATTERY VOLTAGE
(11 - 14V)
6 B/P ECCS groundEngine is running.
Idle speedEngine ground
7W
Data link connec-
tor for CONSULTEngine is running.
Idle speedConnect CONSULT and select DATA
MONITOR mode.Approximately 0.1V
14 Y/RApproximately 3.5V
15 LApproximately4-6V
23 LApproximately 0V
11 G/RAir conditioner
relayEngine is running.
Both air conditioner switch and blower fan
switch are ``ON''. (Compressor operates.)Approximately 1V
Engine is running.
Air conditioner switch is ``OFF''.BATTERY VOLTAGE
(11 - 14V)
12 G/YSwirl control valve
control solenoid
valveEngine is running.
Idle speed0-1V
Engine is running.
Engine speed is above 3,600 rpm.BATTERY VOLTAGE
(11 - 14V)
13 B/P ECCS groundEngine is running.
Idle speedEngine ground
16 BMass air flow
sensorEngine is running.
(Warm-up condition)
Idle speed1.3 - 1.7V
Engine is running.
(Warm-up condition)
Engine speed is 2,500 rpm.1.7 - 2.1V
17 WMass air flow
sensor groundEngine is running.
(Warm-up condition)
Idle speed0.005 - 0.02V
18 LG/REngine coolant
temperature sen-
sorEngine is running.
Approximately 0 - 4.8V
Output voltage varies with
engine coolant temperature.
19 WHeated oxygen
sensorEngine is running.
After warming up sufficiently and engine
speed is 2,000 rpm0 - Approximately 1.0V
(periodically change)
20 LGThrottle position
sensorIgnition switch ``ON''
(Warm-up condition)
Accelerator pedal released0.35 - 0.65V
Ignition switch ``ON''
Accelerator pedal fully depressedApproximately 4V
21
29B/G
B/GSensors' groundEngine is running.
(Warm-up condition)
Idle speed0.001 - 0.02V
TROUBLE DIAGNOSIS Ð General DescriptionKA
ECM Terminals and Reference Value
(Cont'd)
EC-70

Engine Coolant Temperature Sensor (ECTS)
COMPONENT DESCRIPTION
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 tempera-
ture
ÉC (ÉF)Voltage*
(V)Resistance
(kW)
þ10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 1.0 0.236 - 0.260
*: These data are reference values and are measured between ECM termi-
nal
V18(Engine coolant temperature sensor) and ECM terminalV39(ECCS
ground).
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ...Check Items
(Possible Cause)
13
lAn excessively high or low voltage from the sensor is
sent to ECM.*lHarness or connectors
(The sensor circuit is open or shorted.)
lEngine coolant temperature sensor
*: When this malfunction is detected, the ECM enters fail-safe mode.
Engine operating condition in fail-safe mode ConditionEngine coolant temperature decided
(CONSULT DISPLAY)
Engine coolant temperature will be determined
by ECM based on the time after turning igni-
tion switch ``ON'' or ``START''.
CONSULT displays the engine coolant tem-
perature decided by ECM.Just as ignition switch is turned ON or START 20ÉC (68ÉF)
More than 6 minutes after ignition START 80ÉC (176ÉF)
Except as shown above20 - 80ÉC (68 - 176ÉF)
(Depends on the time)
DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
1) Turn ignition switch ``ON''.
2) Select ``DATA MONITOR'' mode with CONSULT.
3) Wait at least 5 seconds.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Turn ignition switch ``ON'' and wait at least 5 seconds.
2) Turn ignition switch ``OFF'', wait at least 5 seconds and
then turn ``ON''.
3) Perform ``Diagnostic Test Mode II (Self-diagnostic
results)'' with ECM.
SEF594K
SEF012P
SEF759T
TROUBLE DIAGNOSIS FOR ``COOLANT TEMP SEN'' (DTC 13)KA
EC-95

HEC343
TROUBLE DIAGNOSIS FOR ``COOLANT TEMP SEN'' (DTC 13)KA
Engine Coolant Temperature Sensor (ECTS)
(Cont'd)
EC-96

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect engine coolant temperature
sensor harness connector.
3. Turn ignition switch ``ON''.
4. Check voltage between terminal
V2
and ground with CONSULT or tester.
Voltage:
Approximately 5V
OK
cNG
Repair harness or connec-
tors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Check harness continuity between ter-
minal
V1and engine ground.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
lHarness for open or
short between ECM and
engine coolant tempera-
ture sensor
If NG, repair open circuit,
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENT
(Engine coolant temperature sensor).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace engine coolant
temperature sensor.
Disconnect and reconnect harness con-
nectors 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 harness
connector and retest.
INSPECTION END
SEF083U
SEF645R
SEF646R
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``COOLANT TEMP SEN'' (DTC 13)KA
Engine Coolant Temperature Sensor (ECTS)
(Cont'd)
EC-97

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 - 1.00
90 (194) 0.236 - 0.260
If NG, replace engine coolant temperature sensor.
SEF152P
SEF012P
TROUBLE DIAGNOSIS FOR ``COOLANT TEMP SEN'' (DTC 13)KA
Engine Coolant Temperature Sensor (ECTS)
(Cont'd)
EC-98

Overheat
ON BOARD DIAGNOSIS LOGIC
If the cooling fan or another component in the cooling system malfunctions, the engine coolant temperature
will rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
Diagnostic trouble
code No.Malfunction is detected when ...Check Items
(Possible Cause)
28
lEngine coolant temperature reaches an abnormally
high temperature.lCooling fan
lRadiator hose
lRadiator
lRadiator cap
lWater pump
lThermostat
For more information, refer to ``MAIN 12
CAUSES OF OVERHEATING'', EC-108.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in MA sec-
tion (``Changing Engine Coolant'', ``ENGINE MAINTENANCE''). Also, replace the engine oil.
lFill radiator with coolant up to specified level with a filling speed of 2 liters per minute like pour-
ing coolant by kettle. Be sure to use coolant with the proper mixture ratio. Refer to MA section
(``Anti-freeze Coolant Mixture Ratio'', ``RECOMMENDED FLUIDS AND LUBRICANTS'').
lAfter refilling coolant, run engine to ensure that no water-flow noise is emitted.
OVERALL FUNCTION CHECK
WARNING:
Never remove the radiator cap when the engine is hot. Seri-
ous burns could be caused by high pressure fluid escaping
from the radiator.
Wrap a thick cloth around cap. Carefully remove the cap by
turning it a quarter turn to allow built-up pressure to escape.
Then turn the cap all the way off.
1. Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is
below the proper range, skip the following step and go to
``DIAGNOSTIC PROCEDURE'' on next page.
2. Confirm whether customer filled the coolant or not. If cus-
tomer filled the coolant, go to ``DIAGNOSTIC PROCEDURE''
on next page.
AEC640
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)KA
EC-106

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK COOLING SYSTEM FOR LEAK.
Apply pressure to the cooling system with a
tester, and check if the pressure drops.
Testing pressure:
157 kPa (1.57 bar, 1.6 kg/cm
2, 23 psi)
Pressure should not drop.
CAUTION:
Higher than the specified pressure may
cause radiator damage.
OK
cNG
Check the following for leak.
lHoselRadiatorlWater pump
Refer to LC section (``Water
Pump'').
CHECK RADIATOR CAP.
Apply pressure to cap with a tester.
Radiator cap relief pressure:
78 - 98 kPa (0.78 - 0.98 bar, 0.8 - 1.0
kg/cm
2, 11 - 14 psi)
OK
cNG
Replace radiator cap.
CHECK THERMOSTAT.
1. Check valve seating condition at normal
room temperatures.
It should seat tightly.
2. Check valve opening temperature and valve
lift.
Valve opening temperature:
76.5ÉC (170ÉF) [standard]
Valve lift:
More than 10 mm/90ÉC
(0.39 in/194ÉF)
3. Check if valve is closed at 5ÉC (9ÉF) below
valve opening temperature.
For details, refer to LC section (``Thermostat'').
OK
cNG
Replace thermostat.
Check engine coolant temperature sensor.
Refer to ``COMPONENT INSPECTION'',
EC-98.
OK
cNG
Replace engine coolant tem-
perature sensor.
If the cause cannot be isolated, go to ``MAIN
12 CAUSES OF OVERHEATING'' on next
page.
INSPECTION END
Perform FINAL CHECK by the following procedure after
repair is completed.
1. Warm up engine. Run the vehicle for at least 20 minutes. Pay
attention to engine coolant temperature gauge on the instru-
ment panel. If the reading shows an abnormally high
temperature, another part may be malfunctioning.
2. Stop vehicle and let engine idle. Check the intake and exhaust
systems for leaks by listening for noise or visually inspecting
the components.
3. Allow engine to cool and visually check for oil and coolant
leaks. Then, perform ``OVERALL FUNCTION CHECK''.
SLC754AA
SLC755AA
SLC343
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)KA
Overheat (Cont'd)
EC-107

MAIN 12 CAUSES OF OVERHEATING
Engine Step Inspection item Equipment Standard Reference page
OFF 1
lBlocked radiator
lBlocked condenser
lBlocked radiator grille
lBlocked bumper
lVisual No blocking Ð
2
lCoolant mixturelCoolant tester 50 - 50% coolant mixture See ``RECOMMENDED
FLUIDS AND LUBRI-
CANTS'' in MA section.
3
lCoolant levellVisual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
4
lRadiator caplPressure 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 ``System Check'',
``ENGINE COOLING
SYSTEM'' in LC section.
ON*2 5
lCoolant leakslVisual No leaks See ``System Check'',
``ENGINE COOLING
SYSTEM'' in LC section.
ON*2 6
lThermostatlTouch the upper and
lower radiator hosesBoth hoses should be hot. See ``Thermostat'' and
``Radiator'', ``ENGINE
COOLING SYSTEM'' in
LC section.
ON*1 7
lCooling fanlVisual Operating See ``Cooling Fan'',
``ENGINE COOLING
SYSTEM'' in LC section.
OFF 8
lCombustion gas leaklColor checker chemical
tester 4 gas analyzerNegative Ð
ON*3 9
lCoolant temperature
gaugelVisual Gauge less than 3/4
when drivingÐ
lCoolant overflow to res-
ervoir tanklVisual No overflow during driving
and idlingSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
OFF*4 10
lCoolant return from res-
ervoir tank to radiatorlVisual Should be initial level in
reservoir tankSee ``ENGINE MAINTE-
NANCE'' in MA section.
OFF 11
lCylinder headlStraight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See ``Inspection'', ``CYL-
INDER HEAD'' in EM
section.
12
lCylinder block and pis-
tonslVisual No scuffing on cylinder
walls or pistonSee ``Inspection'', ``CYL-
INDER BLOCK'' in EM
section.
*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 ``OVERHEATING CAUSE ANALYSIS'' in LC section.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)KA
Overheat (Cont'd)
EC-108

Idle Air Control Valve (IACV) Ð Auxiliary Air
Control (AAC) Valve
SYSTEM DESCRIPTION
Camshaft position sensorcEngine speed
ECM
(ECCS
control
module)
cIACV-AAC valve
Mass air flow sensorcAmount of intake air
Engine coolant temperature sensor
cEngine coolant temperature
Ignition switch
cStart signal
Throttle position sensor
cThrottle position
Neutral position switch
cNeutral position
Air conditioner switch
cAir conditioner operation
Power steering oil pressure switch
cPower steering load signal
Battery
cBattery voltage
Vehicle speed sensor
cVehicle speed
This system automatically controls engine idle speed to a specified level. Idle speed is controlled through
fine adjustment of the amount of air which by-passes the throttle valve via IACV-AAC valve. The IACV-AAC
valve repeats ON/OFF operation according to the signal sent from the ECM. The camshaft position sensor
detects the actual engine speed and sends a signal to the ECM. The ECM then controls the ON/OFF time
of the IACV-AAC valve so that engine speed coincides with the target value memorized in ECM. The tar-
get engine speed is the lowest speed at which the engine can operate steadily. The optimum value stored
in the ECM is determined by taking into consideration various engine conditions, such as during warm up,
deceleration, and engine load (air conditioner and power steering operation).
COMPONENT DESCRIPTION
IACV-ACC valve
The IACV-AAC valve is moved by ON/OFF pulses from the
ECM. The longer the ON pulse, the greater the amount of air that
will flow through the valve. The more air that flows through the
valve, the higher the idle speed.
SEF040E
TROUBLE DIAGNOSIS FOR NON-DETECTABLE ITEMSKA
EC-131

Swirl Control Valve Control Solenoid Valve
SYSTEM DESCRIPTION
Throttle position sensorcThrottle position (Idle position)
ECM
(ECCS
control
module)
c
Swirl con-
trol valve
control
solenoid
valveIgnition switchcStart signal
Camshaft position sensor
cEngine speed
Mass air flow sensor
cAmount of intake air
Engine coolant temperature sensor
cEngine coolant temperature
This system has a swirl control valve in the intake
passage of each cylinder.
While idling and during low engine speed
operation, the swirl control valve closes. Thus the
velocity of the air in the intake passage increases,
promoting the vaporization of the fuel and produc-
ing a swirl in the combustion chamber.
Because of this operation, this system tends to
increase the burning speed of the gas mixture,
improve fuel consumption, and increase the stabil-
ity in running conditions.
Also, except when idling and during low engine
speed operation, this system opens the swirl con-
trol valve. In this condition, this system tends to
increase power by improving intake efficiency via
reduction of intake flow resistance, intake flow.The solenoid valve controls swirl control valve's
shut/open condition. This solenoid valve is oper-
ated by the ECM.
Throttle posi-
tion switchEngine speedSwirl control
valve control
solenoid
valveSwirl control
valve
IdleBelow
3,600 rpmON Closed
Except idleMore than
3,600 rpmOFF Open
When engine coolant temperature is below 0ÉC (32ÉF) swirl
control valve is kept open.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
SWRL CONT S/V
lEngine is running at a speed of less than 3,600 rpm. ON
lExcept above OFF
ECM TERMINALS AND REFERENCE VALUE
Remarks: Specification data are reference values, and are measured between each terminal andV39(ECCS ground) with a voltme-
ter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC voltage)
12 GYSwirl control valve control
solenoid valveEngine is running.
Idle speed0-1V
Engine is running.
Engine speed is above 3,600 rpm.BATTERY VOLTAGE
(11 - 14V)
TROUBLE DIAGNOSIS FOR NON-DETECTABLE ITEMSKA
EC-161