check 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

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

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

11 CHECK ACCELERATOR POSITION SENSOR SHIELD CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between harness connector F55 terminal 13 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OK (With CONSULT-II)cGO TO 13.
OK (Without CONSULT-II)cGO TO 14.
NGcGO TO 12.
12 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M47, F55
+Harness for open or short between harness connector F55 and engine ground
cRepair harness or connectors.
13 RESET ACCELERATOR POSITION SENSOR IDLE POSITION MEMORY
With CONSULT-II
1. Turn ignition switch ªONº.
2. Select ªOFF ACCEL PO SIGº in ªACTIVE TESTº mode with CONSULT-II.
3. Touch ªCLEARº.
cGO TO 24.
14 RESET ACCELERATOR POSITION SENSOR IDLE POSITION MEMORY
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Let engine idle for 10 minutes.
cGO TO 24.
DTC 0403 ACCEL POS SENSORYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3527

22 RESET ACCELERATOR POSITION SENSOR IDLE POSITION MEMORY
With CONSULT-II
1. Reconnect all connectors disconnected.
2. Turn ignition switch ªONº.
3. Select ªOFF ACCEL PO SIGº in ªACTIVE TESTº mode with CONSULT-II.
4. Touch ªCLEARº.
cGO TO 24.
23 RESET ACCELERATOR POSITION SENSOR IDLE POSITION MEMORY
Without CONSULT-II
1. Reconnect all connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Let engine idle for 10 minutes.
cGO TO 24.
24 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3469.
cINSPECTION END
DTC 0403 ACCEL POS SENSORYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3530

On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
+An excessively high voltage from the charge air pressure sen-
sor is sent to ECM when engine is running.+Intake air system
+Turbocharger system
+Charge air pressure sensor
+Harness or connectors
(The charge air pressure sensor circuit is shorted.)
DTC Confirmation Procedure
NOTE:
If DTC 0406 ªINT AIR VOLº displayed with DTC 0905
ªTURBO PRESSUREº, perform trouble diagnosis for DTC
0905 ªTURBO PRESSUREº first. (See EC-3601.)
WITH CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and warm it up to normal operating temperature.
4) Drive vehicle.
5) Maintain the engine speed more than 4,000 rpm for at least
10 seconds.
6) If DTC is detected, go to ªDiagnostic Procedureº, EC-3533.
WITHOUT CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Drive vehicle.
3) Maintain the engine speed more than 4,000 rpm for at least
10 seconds.
4) Stop vehicle.
5) Turn ignition switch ªOFFº, wait at least 5 seconds and then
turn ªONº.
6) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º
with ECM.
7) If DTC is detected, go to ªDiagnostic Procedureº, EC-3533.SEF817Y
DTC 0406 INT AIR VOLYD25DDTi
EC-3531