2001 NISSAN PICK-UP engine coolant

SYSTEM Ð ENGINE CONTROL system
Malfunction
SYMPTOM
Reference page
Feature of symptom, Check pointROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEAT/HIGH ENGINE COOLANT TEMPERATURE
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
ABNORMAL SMOKE COLOR
DEAD BATTERY (UNDER CHARGE)
Malfunction indicator lamp illuminates.
Can be detected by CONSULT-II?
Fuel cutBLACK SMOKE
WHITE SMOKEWarranty symptom code AG AH AJ AK AL AM AP HA
ENGINE CONTROL
EGR volume control valve circuit*a, *b
EC-3606
*c 1 *8
Glow relay circuit*a 1
EC-3622*9
*b*10
ECM relay (Self-shutoff) circuit*a 111
EC-3471
*b*11
ECM, Connector circuit *a, *b222222222222EC-3502,
3582, 3599
Air conditioner relay circuit*a
EC-3645*12
*b*13
Air conditioner switch circuit*a, *c
EC-3645*13
*b*14
1 - 5: The numbers refer to the order of inspection.
*a: Open
*b: Short
*c: Ground short
*d: Noise
*8: Does not stop operating.
*9: Glow lamp does not turn on.
*10: Glow lamp does not turn off.
*11: Ground short makes engine unable to stop.
*12: Air conditioner does not operate.
*13: Air conditioner does not stop operating.
*14: Air conditioner does not work.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD25DDTi
Symptom Matrix Chart (Cont'd)
EC-3459

TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA (DC Voltage and Pulse
Signal)
15 G/W Air conditioner relayEngine is running.
Air conditioner switch is ªOFFºBATTERY VOLTAGE
(11 - 14V)
Engine is running.
Both air conditioner switch and blower fan
switch are ªONº
(Compressor is operating)Approximately 0.1V
16 L/W Glow lampIgnition switch ªONº
Glow lamp is ªONºApproximately 1V
Ignition switch ªONº
Glow lamp is ªOFFºBATTERY VOLTAGE
(11 - 14V)
17 G/Y Stop lamp switchIgnition switch ªONº
Brake pedal fully releasedApproximately 0V
Ignition switch ªONº
Brake pedal depressedBATTERY VOLTAGE
(11 - 14V)
18 W/GMalfunction indicator
lampIgnition switch ªONº
Approximately 1V
Engine is running.
Idle speedBATTERY VOLTAGE
(11 - 14V)
19 L/OREngine coolant tempera-
ture sensorEngine is running.
Approximately 0 - 4.8V
Output voltage varies with
engine coolant temperature
20 R Start signalIgnition switch ªONº
Approximately 0V
Ignition switch ªSTARTº
BATTERY VOLTAGE
(11 - 14V)
21 Y Air conditioner switchEngine is running.
Air conditioner switch is ªOFFºBATTERY VOLTAGE
(11 - 14V)
Engine is running.
Both air conditioner switch and blower fan
switch are ªONº
(Compressor is operating)Approximately 0V
22 G/ORPark/Neutral position
switchIgnition switch ªONº
Gear position is ªNeutralºApproximately 0V
Ignition switch ªONº
Except the above gear positionBATTERY VOLTAGE
(11 - 14V)
23 WAccelerator position sen-
sorIgnition switch ªONº
Accelerator pedal fully released0.29 - 0.79V
Ignition switch ªONº
Accelerator pedal fully depressed3.48 - 4.64V
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD25DDTi
ECM Terminals and Reference Value
(Cont'd)
EC-3465

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) 2.3 0.68 - 1.0
90 (194) 1.0 0.236 - 0.260
*: These data are reference values and measured between ECM terminal 19
(Engine coolant temperature sensor) 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.
On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
+An excessively high or low voltage from the sensor is entered
to ECM.+Harness or connectors (The sensor circuit is open or shorted.)
+Engine coolant temperature sensor
DTC Confirmation Procedure
WITH CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 5 seconds.
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-3483.
WITHOUT CONSULT-II
1) Turn ignition switch ªONº and wait at least 5 seconds.
2) Turn ignition switch ªOFFº, wait at least 5 seconds and then
turn ªONº.
3) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º
with ECM.
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-3483.
SEF594K
SEF012P
SEF817Y
DTC 0103 COOLANT TEMP SENYD25DDTi
EC-3480

Diagnostic Procedure
1 CHECK ECTS POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect engine coolant temperature sensor harness connector.
SEC230D
3. Turn ignition switch ªONº.
4. Check voltage between ECTS terminal 2 and ground with CONSULT-II or tester.
SEF401Y
OK or NG
OKcGO TO 3.
NGcGO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E237, M279 (LHD models)
+Harness connectors E237, F36 (RHD models)
+Harness for open or short between engine control temperature sensor and ECM
cRepair open circuit or short to ground or short to power in harness or connectors.
3 CHECK ECTS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between ECTS terminal 1 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OKcGO TO 5.
NGcGO TO 4.
DTC 0103 COOLANT TEMP SENYD25DDTi
EC-3482

4 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E237, M279 (LHD models)
+Harness connectors E237, F36 (RHD models)
+Harness for open or short between engine coolant temperature sensor and ECM
cRepair open circuit or short to ground or short to power in harness or connectors.
5 CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Remove engine coolant temperature sensor from the engine.
2. Check resistance between ECTS terminals 1 and 2 as shown in the figure.
SEF304X
OK or NG
OKcGO TO 6.
NGcReplace engine coolant temperature sensor.
6 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3469.
cINSPECTION END
DTC 0103 COOLANT TEMP SENYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3483

Description
SYSTEM DESCRIPTION
Sensor Input signal to ECM ECM function Actuator
Vehicle speed sensor Vehicle speed
Cooling fan con-
trolCooling fan relay Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch Air conditioner ªONº signal
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature. The
control system has 2-step control [ON/OFF].
OPERATION
*: Refer to HA section.
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
AIR COND RLY+Engine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
COOLING FAN+When cooling fan is stopped. OFF
+When cooling fan operates. ON
SEC242D
DTC 0208 OVER HEATYD25DDTi
EC-3489

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 CONDITION DATA (DC Voltage)
14 G/B Cooling fan relayEngine is running.
Cooling fan is not operatingBATTERY VOLTAGE
(11 - 14V)
Engine is running.
Cooling fan is operatingApproximately 0.1V
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)
+Cooling fan does not operate properly (Overheat).
+Cooling fan system does not operate properly (Overheat).
+Engine coolant was not added to the system using the proper
filling method.+Harness or connectors
(The cooling fan circuit is open or shorted.)
+Cooling fan
+Radiator hose
+Radiator
+Radiator cap
+Water pump
+Thermostat
+Fan belt
+Engine coolant temperature sensor
For more information, refer to ªMAIN 12 CAUSES OF
OVERHEATINGº, EC-3501.
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.
1) 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 LUBRICANTS AND FLUIDSº).
2) After refilling coolant, run engine to ensure that no water-flow noise is emitted.
DTC 0208 OVER HEATYD25DDTi
EC-3490

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.
WITH CONSULT-II
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-3494.
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-3494.
3) Turn ignition switch ªONº.
4) Perform ªCOOLING FANº in ªACTIVE TESTº mode with
CONSULT-II and make sure that cooling fans operate when
touching ªONº or ªOFFº.
If NG, go to ªDiagnostic Procedureº, EC-3494.
WITHOUT CONSULT-II
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-3494.
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-3494.
3) Disconnect engine coolant temperature sensor harness con-
nector.
4) Connect 150Wresistor to engine coolant temperature sensor
harness connector.
5) Start engine and make sure that cooling fan operates.
Be careful not to overheat engine.
6) If NG, go to ªDiagnostic Procedureº, EC-3494.
AEC640
SEF111X
SEC636CA
DTC 0208 OVER HEATYD25DDTi
EC-3491