engine NISSAN PICK-UP 2001 Repair Manual

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
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The unit controls the
engine.
On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
+ECM calculation function is malfunctioning.+ECM
(ECCS-D control module)
DTC Confirmation Procedure
WITH CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and wait at least 2 seconds.
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-3503.
WITHOUT CONSULT-II
1) Turn ignition switch ªONº and wait at least 2 seconds.
2) Start engine and wait at least 2 seconds.
3) Turn ignition switch ªOFFº, wait at least 5 seconds and then
turn ªONº.
4) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º
with ECM.
5) If DTC is detected, go to ªDiagnostic Procedureº, EC-3503.
SEC220B
SEF817Y
DTC 0301 ECM 2, DTC 901 ECM 12YD25DDTi
EC-3501

3 CHECK GROUND CIRCUIT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between terminal 1 and engine ground.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OKcGO TO 5.
NGcGO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E101, M5
+Harness connectors M48, F54 (RHD models)
+Harness for open or short between ECM and intake air temperature sensor
cRepair open circuit or short to power in harness or connectors.
5 CHECK INTAKE AIR TEMPERATURE SENSOR
Check resistance between intake air temperature sensor terminals 1 and 2 as shown in the figure.
SEC165D
OK or NG
OKcGO TO 6.
NGcReplace intake air temperature sensor.
6 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3469.
cINSPECTION END
DTC 0401 INTAKE AIR TEMPERATURE SENSORYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3507

Description
SYSTEM DESCRIPTION
The ECM and the electronic control fuel injection pump control
unit (abbreviated as the injection pump control unit) perform the
real time communication (signal exchange).
The ECM transmits the signals of the target fuel injection
amount, target fuel injection timing, and engine speed, etc., and
receives the signals of the pump speed and fuel temperature,
etc. from the injection pump control unit.
By those signals, the injection pump controls the optimum fuel
injection amount and injection timing of the spill valve and tim-
ing control valve.
Injection pump control unit has an on board diagnostic system,
which detects malfunctions related to sensors or actuators built-
into electronic control fuel injection pump. These malfunction
information are transferred through the line (circuit) from injection
pump control unit to ECM.
FUEL INJECTION AMOUNT CONTROL
In accordance with the target fuel injection amount signal from
the ECM, the injection amount is controlled by controlling the spill
valve in the injection pump and by changing the needle opening
time.
FUEL INJECTION TIMING CONTROL
Based on the target fuel injection timing signal from the ECM, the
injection timing is controlled in accordance with the timer spring
by performing the duty control of the timing control valve in the
injection pump and by adjusting the pressure of the timer piston
high pressure chamber.
FUEL TEMPERATURE SENSOR
The sensor detects the fuel temperature in the injection pump
and calibrates the injection amount change by the fuel tempera-
ture.
CAM RING POSITION SENSOR
The sensor detects the passing of the protrusion on the sensor
wheel in the injection pump by the semiconductor magnetic
resistance element sensor. The cam ring position sensor syn-
chronizes with the cam ring, and detects the actual advance
amount. The injection pump control unit measures the injection
pump revolution by the signal of the cam ring position sensor.
SEF437Y
DTC 0402 P9zFUEL TEMP SENYD25DDTi
EC-3508

CONSULT-II Reference Value in Data Monitor
Mode
Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL TEMP SEN+Engine: After warming up More than 40ÉC (104ÉF)
SPILL/V+Engine: After warm-
ing upIdle Approx. 13ÉCA
INJ TIMG C/V+Engine: After warming up,
idle the engine.Approx. 50 - 70%
DECELER F/CUT+Engine: After warm-
ing upIdle OFF
BARO SEN+Ignition switch: ONAltitude
Approx.0m(0ft): Approx. 100.62 kPa (1.0062 bar, 1.026 kg/cm
2, 14.59
psi)
Approx. 1,000 m (3,281 ft): Approx. 88.95 kPa (0.8895 bar, 0.907 kg/cm
2,
12.90 psi)
Approx. 1,500 m (4,992 ft): Approx. 83.16 kPa (0.8316 bar, 0.848 kg/cm
2,
12.06 psi)
Approx. 2,000 m (6,562 ft): Approx. 78.36 kPa (0.7836 bar, 0.799 kg/cm
2,
11.36 psi)
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)
33 G/YElectronic control fuel
injection pumpEngine is running.
Warm-up condition
Idle speedApproximately 2.4V
40 PUElectronic control fuel
injection pumpEngine is running.
Warm-up condition
Idle speedApproximately 2.4V
52 L/WElectronic control fuel
injection pumpEngine is running.
Idle speedApproximately 0.1V
53 L/RElectronic control fuel
injection pumpEngine is running.
Idle speedApproximately 0.45V
Engine is running.
Engine speed is 2,000 rpmApproximately 0.7V
DTC 0402 P9zFUEL TEMP SENYD25DDTi
EC-3509

On Board Diagnosis Logic
Malfunction is detected when .... Check Items (Possible cause)
+An improper voltage signal from fuel temperature sensor
(Built-into electronic control fuel injection pump) is sent to
injection pump control unit.+Harness or connectors
(Electronic control fuel injection pump circuit is open or
shorted.)
+Electronic control fuel injection pump
DTC Confirmation Procedure
WITH CONSULT-II
1) Turn ignition switch ªONº and wait at least 2 seconds.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and run it for at least 2 seconds at idle speed.
(If engine does not run, turn ignition switch to ªSTARTº for at
least 2 seconds.)
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-3514.
WITHOUT CONSULT-II
1) Turn ignition switch ªONº and wait at least 2 seconds.
2) Start engine and run it for at least 2 seconds at idle speed.
(If engine does not run, turn ignition switch to ªSTARTº for at
least 2 seconds.)
3) Turn ignition switch ªOFFº, wait at least 5 seconds and then
turn ªONº.
4) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º
with ECM.
5) If DTC is detected, go to ªDiagnostic Procedureº, EC-3514.
SEF817Y
DTC 0402 P9zFUEL TEMP SENYD25DDTi
EC-3510

4 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E236, M278 (LHD models)
+Harness connectors E236, F35 (RHD models)
+Harness for open or short between electronic control fuel injection pump and engine ground
cRepair open circuit or short to ground or short to power in harness or connectors.
5 CHECK COMMUNICATION LINE FOR OPEN AND SHORT
1. Check continuity between the following terminals. Refer to Wiring Diagram.
MTBL0444
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OKcGO TO 7.
NGcGO TO 6.
6 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E237, M279 (LHD models)
+Harness connectors E237, F36 (RHD models)
+Harness for open or short between electronic control fuel injection pump and ECM
cRepair open circuit or short to ground or short to power in harness or connectors.
7 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3469.
OK or NG
OKcReplace electronic control fuel injection pump.
NGcRepair open circuit or short to ground or short to power in harness or connectors.
DTC 0402 P9zFUEL TEMP SENYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3514

Description
The accelerator work unit is installed on the upper end of the accelerator pedal assembly. The sensor detects
the accelerator position and sends a signal to the ECM. The ECM uses the signal to determine the amount
of fuel to be injected.
The accelerator position switch detects Off-accelerator switch signal and Full-accelerator switch signal and
send these signals to the ECM. The ECM will then determine engine idle conditions. These signals are also
used for diagnosing the accelerator position sensor.
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
ACCEL POS SEN+Ignition switch: ON
(Engine stopped)Accelerator pedal: released 0.29 - 0.79V
Accelerator pedal: depressed 3.48 - 4.64V
FULL ACCEL SW+Ignition switch: ON
(Engine stopped)Accelerator pedal: fully depressed ON
Except above OFF
OFF ACCEL SW+Ignition switch: ON
(Engine stopped)Accelerator pedal: fully released ON
Accelerator pedal: slightly open OFF
SEC262D
DTC 0403 ACCEL POS SENSORYD25DDTi
EC-3515

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)
23 WAccelerator position sen-
sorIgnition switch ªONº
Accelerator pedal fully released0.29 - 0.79V
Ignition switch ªONº
Accelerator pedal fully depressed3.48 - 4.64V
31 YAccelerator position switch
(Idle)Ignition switch ªONº
Accelerator pedal fully releasedBATTERY VOLTAGE
(11 - 14V)
Ignition switch ªONº
Accelerator pedal depressedApproximately 0V
32 GAccelerator position switch
(Full)Ignition switch ªONº
Accelerator pedal releasedApproximately 0V
Ignition switch ªONº
Accelerator pedal fully depressedBATTERY VOLTAGE
(11 - 14V)
48 OR/LAccelerator position sen-
sor power supplyIgnition switch ªONº
Approximately 5V
51 B/WAccelerator position sen-
sor groundEngine is running.
Warm-up condition
Idle speedApproximately 0V
On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
+The relation between sensor and switch signal is not in the
normal range during the specified accelerator position.+Harness or connectors
(The sensor circuit is open or shorted.)
+Accelerator position sensor
+Accelerator position switch
DTC 0403 ACCEL POS SENSORYD25DDTi
EC-3516

5 CHECK ACCELERATOR POSITION SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screw.
SEC245D
3. Check harness continuity between accelerator work unit terminal 3 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OKcGO TO 7.
NGcGO TO 6.
6 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors F54, M48 (RHD models)
+Harness for open or short between ECM and accelerator work unit
cRepair open circuit or short to ground or short to power in harness or connectors.
7 CHECK ACCELERATOR POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 23 and accelerator work unit terminal 2. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK (With CONSULT-II)cGO TO 9.
OK (Without CONSULT-II)cGO TO 10.
NGcGO TO 8.
8 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors F55, M47 (RHD models)
+Harness for open or short between ECM and accelerator work unit
cRepair open circuit or short to ground or short to power in harness or connectors.
DTC 0403 ACCEL POS SENSORYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3525