2001 NISSAN ALMERA cooling

9 CHECK COOLING FAN MOTORS-1 AND -2
Refer to ªComponent Inspectionº, EC-416.
OK or NG
OK©GO TO 10.
NG©Replace cooling fan motors.
10 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
11 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/cm2, 23 psi)
CAUTION:
Higher than the specified pressure may cause radiator damage.
SLC754A
Pressure should not drop.
OK or NG
OK©GO TO 12.
NG©Check the following for leak
+Hose
+Radiator
+Water pump
Refer to LC-14, ªWater Pumpº.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Diagnostic Procedure (Cont'd)
EC-413

12 CHECK RADIATOR CAP
Apply pressure to cap with a tester.
SLC755A
Radiator cap relief pressure:
59 - 98 kPa (0.59 - 0.98 bar, 0.6 - 1.0 kg/cm2,9-14psi)
OK or NG
OK©GO TO 13.
NG©Replace radiator cap.
13 CHECK THERMOSTAT
1. Check valve seating condition at normal room temperatures.
It should seat tightly.
2. Check valve opening temperature and valve lift.
SLC343
Valve opening temperature:
82ÉC (180ÉF) [standard]
Valve lift:
More than 8 mm/95ÉC (0.31 in/203ÉF)
3. Check if valve is closed at 5ÉC (9ÉF) below valve opening temperature.
For details, refer to LC section (ªThermostatº).
OK or NG
OK©GO TO 14.
NG©Replace thermostat
14 CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to ªCOMPONENT INSPECTIONº, EC-206.
OK or NG
OK©GO TO 15.
NG©Replace engine coolant temperature sensor.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Diagnostic Procedure (Cont'd)
EC-414

15 CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to ªMAIN 12 CAUSES OF OVERHEATINGº, EC-416.
©INSPECTION END
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Diagnostic Procedure (Cont'd)
EC-415

Main 12 Causes of Overheating=NJEC0492
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 50 - 50% coolant mixture See MA-16, ªRECOM-
MENDED FLUIDS AND
LUBRICANTSº.
3+Coolant level+Visual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee LC-18, ªChanging
Engine Coolantº.
4+Radiator cap+Pressure tester 59 - 98 kPa
(0.59 - 0.98 bar, 0.6 - 1.0
kg/cm
2,9-14psi) (Limit)See LC-10, ªSystem
Checkº.
ON*
25+Coolant leaks+Visual No leaks See LC-10, ªSystem
Checkº.
ON*
26+Thermostat+Touch the upper and
lower radiator hosesBoth hoses should be
hotSee LC-15, ªThermostatº
and LC-16, ªRadiatorº.
ON*
17+Cooling fan+CONSULT-II Operating See ªTROUBLE DIAG-
NOSIS FOR OVER-
HEATº (EC-406).
OFF 8+Combustion gas leak+Color checker chemi-
cal tester 4 Gas ana-
lyzerNegative Ð
ON*
39+Coolant temperature
gauge+Visual Gauge less than 3/4
when drivingÐ
+Coolant overflow to
reservoir tank+Visual No overflow during driv-
ing and idlingSee LC-18, ªChanging
Engine Coolantº.
OFF*
410+Coolant return from
reservoir tank to radia-
tor+Visual Should be initial level in
reservoir tankSee LC-19, ªRefilling
Engine Coolantº.
OFF 11+Cylinder head+Straight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See EM-37, ªInspectionº,
ªCYLINDER HEADº.
12+Cylinder block and
pistons+Visual No scuffing on cylinder
walls or pistonSee EM-56, ªInspectionº,
ªCYLINDER BLOCKº.
*1: Turn the ignition switch ON.
*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 LC-24, ª OVERHEATING CAUSE ANALYSISº.
SEF745U
Component InspectionNJEC0493COOLING FAN RELAYNJEC0493S01Check continuity between terminals 3 and 5, 6 and 7.
Conditions Continuity
12V direct current supply between terminals 1 and
2Ye s
No current supply No
If NG, replace relay.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Main 12 Causes of Overheating
EC-416

SEF610Y
COOLING FAN MOTORS-1 AND -2NJEC0493S021. Disconnect cooling fan motor harness connectors.
2. Supply cooling fan motor terminals with battery voltage and
check operation.
Terminals
(+) (þ)
Cooling fan motor 2 1
Cooling fan motor should operate.
If NG, replace cooling fan motor.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Component Inspection (Cont'd)
EC-417

DescriptionNJEC1758SYSTEM DESCRIPTIONNJEC1758S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
Idle air
controlIACV-AAC valve Camshaft position sensor (PHASE) Engine speed and cylinder number
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
PNP switch Park/Neutral position
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Battery Battery voltage
Vehicle speed sensor Vehicle speed
Cooling fan Cooling fan operation
Electrical load Electrical load signal
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 changes the opening of the air by-pass
passage to control the amount of auxiliary air. This valve is actu-
ated by a step motor built into the valve, which moves the valve in
the axial direction in steps corresponding to the ECM output sig-
nals. One step of IACV-AAC valve movement causes the respec-
tive opening of the air by-pass passage. (i.e. when the step
advances, the opening is enlarged.) The opening of the valve is
varied to allow for optimum control of the engine idling speed. The
crankshaft position sensor (POS) detects the actual engine speed
and sends a signal to the ECM. The ECM then controls the step
position of the IACV-AAC valve so that engine speed coincides with
the target value memorized in ECM. The target engine speed is the
lowest speed at which the engine can operate steadily. The opti-
mum value stored in the ECM is determined by taking into consid-
eration various engine conditions, such as during warm up,
deceleration, and engine load (air conditioner, power steering, cool-
ing fan operation and electrical load).
SEF937W
COMPONENT DESCRIPTIONNJEC1758S02IACV-AAC ValveNJEC1758S0201The IACV-AAC valve is operated by a step motor for centralized
control of auxiliary air supply. This motor has four winding phases
and is actuated by the output signals of ECM which turns ON and
OFF two windings each in sequence. Each time the IACV-AAC
valve opens or closes to change the auxiliary air quantity, the ECM
sends a pulse signal to the step motor. When no change in the
auxiliary air quantity is needed, the ECM does not issue the pulse
signal. A certain voltage signal is issued so that the valve remains
at that particular opening.
IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Description
EC-511

JEF147Y
DescriptionNJEC0580The refrigerant pressure sensor is installed at the liquid tank of the
air conditioner system. The sensor uses an electrostatic volume
pressure transducer to convert refrigerant pressure to voltage. The
voltage signal is sent to ECM, and ECM controls cooling fan sys-
tem.
SEF099X
ECM Terminals and Reference ValueNJEC0581Specification 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 Sensor's ground[Engine is running]
+Warm-up condition
+Idle speedApproximately 0V
74 R/LRefrigerant pressure
sensor[Engine is running]
+Warm-up condition
+Both A/C switch and blower switch are ªONº
(Compressor operates.)1.0 - 4.0V
111 R Sensor's power supply[Ignition switch ªONº]Approximately 5V
REFRIGERANT PRESSURE SENSORQG
Description
EC-572

System ChartNJEC0611
Input (Sensor) ECM Function Output (Actuator)
+Electronic control fuel injection pump
+Crankshaft position sensor (TDC)
+Engine coolant temperature sensor
+Accelerator position sensor
+Accelerator position switch
+Park/Neutral position (PNP) switch*
+Ignition switch
+Battery voltage
+Vehicle speed sensor
+Air conditioner switch
+Mass air flow sensor
+Stop lamp switchFuel injection controlElectronic control fuel injection
pump
Fuel injection timing controlElectronic control fuel injection
pump
Fuel cut controlElectronic control fuel injection
pump
Glow control system Glow relay & glow lamp
On board diagnostic system MI (On the instrument panel)
EGR volume control EGR volume control valve
Cooling fan control Cooling fan relay
Air conditioning cut control Air conditioner relay
*: If so equipped
ENGINE AND EMISSION CONTROL OVERALL SYSTEMYD
System Chart
EC-609