1999 NISSAN PRIMERA Control

Cooling Fan (Overheat)
SYSTEM DESCRIPTION
Vehicle speed sensorEVehicle speed
ECM
ECooling
fan
relay(s)Engine coolant temperature sensorEEngine coolant temperature
Air conditioner switch
EAir conditioner ªONº signal
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, air con-
ditioner system pressure and air conditioner ON signal. The control system has 3-step control [HIGH/LOW/
OFF]. This system indirectly relates to diagnostic trouble code 28 (Overheat).
Operation
ON-BOARD DIAGNOSIS LOGIC
This diagnosis continuously monitors the engine coolant temperature.
If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
Malfunction is detected when ...Check Items
(Possible Cause)
lAn excessive high engine coolant temperature sensor sig-
nal is detected by the ECM. (Overheat)lHarness or connectors
(The cooling fan circuit is open or shorted.)
lCooling fan
lRadiator hose
lRadiator
lRadiator cap
lWater pump
lThermostat
lFan belt
lEngine coolant temperature sensor
For more information, refer to ª12 MAIN CAUSES OF
OVERHEATINGº, EC-CD-95.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in the MA
section (ªChanging Engine Coolantº, ªENGINE MAINTENANCEº). Also, replace the engine oil.
a. Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Be sure
to use coolant with the proper mixture ratio. Refer to MA section (ªAnti-freeze Coolant Mixture
Ratioº, ªRECOMMENDED FLUIDS AND LUBRICANTSº).
b. After refilling coolant, run engine to ensure that no water-flow noise is emitted.
NEF772
Engine coolant
temperature ÉC (ÉF)
Air conditioner is OFF
.102 (216)
.96 (205)
.20
(12).80
(50)
Vehicle speed km/h (mph)
Cooling fans do not operateCooling fans operate at high speed
Engine coolant
temperature ÉC (ÉF)
Vehicle speed km/h (mph)
.20
(12).80
(50)
.102 (216)
.96 (205)Air conditioner is ON
Cooling fans operate at low speed
TROUBLE DIAGNOSIS 8CD20T
EC-87

OVERALL FUNCTION CHECK
Use this procedure to check the overall function of the cooling
fan. During this check, a DTC might not be confirmed.
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 the 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 steps and go to
ªDIAGNOSTIC PROCEDUREº, EC-CD-90.
2) Confirm whether customer filled the coolant or not. If cus-
tomer filled the coolant, skip the following steps and go to
ªDIAGNOSTIC PROCEDUREº, EC-CD-90.
3) Turn ignition switch to ªONº position.
4) Perform ªCOOLING FANº in ªACTIVE TESTº mode
with CONSULT-II (LOW speed and HI speed).
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
3) Start engine.
Be careful not to overheat engine.
4) Set temperature control switch to full cold position.
5) Push Air Conditioner switch to ªONº position.
6) Turn blower fan switch to ªONº position.
7) Run engine at idle for a few minutes with Air Con-
ditioner operating.
Be careful not to overheat engine.
8) Make sure that both cooling fans operate at low
speed.
9) Turn ignition switch to ªLOCKº position.
10) Push Air Conditioner switch and blower fan switch
to ªOFFº position.
11) Disconnect engine coolant temperature sensor
harness connector.
12) Connect 150Wresistor to engine coolant tempera-
ture sensor harness connector.
13) Restart engine and make sure that both cooling
fans operate at higher speed than low speed.
Be careful not to overheat engine.
AEC640 MAX.
MIN.OK
SEF111X
SEC163BA
MEC475B Cooling fan
Engine coolant
temperature sensor
harness connector
150Wresistor
TROUBLE DIAGNOSIS 8CD20T
Cooling Fan (Overheat) (Cont'd)
EC-88

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK COOLING FAN LOW
SPEED OPERATION.
1. Disconnect cooling fan relay-3.
2. Turn ignition switch to ªONº
position.
3. Perform ªCOOLING FANº
in ªACTIVE TESTº mode
with CONSULT-II.
-------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------
2. Start engine.
3. Set temperature switch at
full cold position.
4. Turn Air Conditioner switch
to ªONº position.
5. Turn blower fan switch to
ªONº position.
6. Run engine at idle speed
for a few minutes with Air
Conditioner operating.
7. Make sure that both cool-
ing fans operate at low
speed.
OK
ENG
Check cooling fan low
speed control circuit.
(Go to
PROCEDURE A
.)
CHECK COOLING FAN HIGH
SPEED OPERATION.
1. Turn ignition switch to ªLOCKº
position.
2. Reconnect cooling fan relay-3.
3. Disconnect cooling fan relay-1.
4. Turn ignition switch to ªONº
position.
5. Perform ªCOOLING FANº
in ªACTIVE TESTº mode
with CONSULT-II.
-------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------
4. Turn Air Conditioner switch
and blower fan switch to
ªOFFº position.
5. Disconnect engine coolant
temperature sensor har-
ness connector.
6. Connect 150Wresistor to
engine coolant temperature
sensor harness connector.
7. Restart engine and make
sure that both cooling fans
operate at higher speed
than low speed.
OK
ENG
Check cooling fan high
speed control circuit.
(Go to
PROCEDURE B
.)
pB
(Go to EC-CD-94.)
.Cooling fan relay 2
Cooling fan relay-1Cooling fan relay-3
YEC383
SEF111X
NEF809
Cooling fan
SEF111X
YEC384
Cooling fan
Engine coolant
temperature sensor
harness connector
resistor
H
H
H
TROUBLE DIAGNOSIS 8CD20T
Cooling Fan (Overheat) (Cont'd)
EC-90

YEC807
BATTERY
Refer to EL-POWER.
: Detectable line for DTC
: Non-detectable line for DTC
INJECTION PUMP
(FUEL CUT SOLE-
NOID VALVE)
ENGINE
CONTROL
MODULE
RELAY
ECM
TROUBLE DIAGNOSIS 10CD20T
Fuel Cut Solenoid Valve (Cont'd)
EC-101

Crankshaft Position Sensor (TDC)
The crankshaft position sensor (TDC) monitors engine speed by
means of signals from the sensing plate (with two protrusions)
installed to the crankshaft pulley. The datum signal output is
detected at ATDC 70É and sent to the ECM. The sensor signal
is used for fuel injection control and fuel injection timing control.
Malfunction is detected when ....Check Items
(Possible Cause)
lAn incorrect signal from the sensor is detected by ECM
during engine running and cranking.lHarness or connectors
(The sensor circuit is open.)
lCrankshaft position sensor (TDC)
DIAGNOSTIC TROUBLE CONFIRMATION
PROCEDURE
Before performing the following procedure, confirm
that battery voltage is more than 9V.
1) Turn ignition switch to ªONº position and select
ªDATA MONITORº mode with CONSULT-II.
2) Start engine and run it for at least 3 seconds above
1,200 rpm.
SEF615S Core
Magnet
Coil
SEF616S Crank pulley
Crankshaft position
sensor (TDC)
TROUBLE DIAGNOSIS 13CD20E
EC-114

Glow Control System
When coolant temperature is lower than 75ÉC (167ÉF):
lIgnition switch ON
After ignition switch has been turned to ON, the glow relay
turns ON for a period of time depending on engine coolant
temperature, allowing current to flow through the glow plugs.
lStarting
After starting the engine, current will flow through the glow
plugs for 300 seconds, or until the coolant temperature
exceeds 50ÉC (122ÉF).
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.
Malfunction is detected when ....Check Items
(Possible cause)
lGlow relay signal circuit is open or shorted.lHarness or connectors
(The glow relay signal circuit is open or shorted)
lGlow relay
lGlow indicator lamp circuit is open or shorted.lHarness or connectors
(The glow indicator lamp circuit is open or shorted.)
lGlow lamp
Glow lamp indicator
Time,[S]
.
Engine coolant temperature
Pre-glow
Time,[S]
Engine coolant temperature.
Post glow
.Time,[S]
Engine coolant temperature
.1.5
.(-40) (-4) (32) (68) (104) (140)
.(-40) (-4) (32) (68) (104) (140)
.(-40) (-4) (32) (68) (104) (140),ÉC (ÉF).,ÉC (ÉF)
.,ÉC (ÉF)
NEF834
.
.
SEF857S Ceramic heater
Resistor
TROUBLE DIAGNOSES 14CD20T
EC-118

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.
TROUBLE DIAGNOSES 14CD20T
Glow Control System (Cont'd)
EC-119

YEC102A
TROUBLE DIAGNOSES 14CD20T
Glow Control System (Cont'd)
EC-120