2001 NISSAN PICK-UP Repair Manual

2 CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªSELF-LEARNING CONTº in ªWORK SUPPORTº mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching ªCLEARº.
SEF215Z
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0172 detected? Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 3 seconds at idle speed.
AEC131A
4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure 1st trip DTC P0102 is displayed.
6. Erase the 1st trip DTC memory. Refer to ªHOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATIONº,
EC-3060.
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0172 detected? Is it difficult to start engine?
YesorNo
Ye s©Perform trouble diagnosis for DTC P0171 or P0172. Refer to EC-3237 or EC-3244.
No©GO TO 3.
3 CHECK INPUT SIGNAL CIRCUIT
1. Disconnect heated oxygen sensor 2 harness connector and ECM harness connector.
2. Check harness continuity between ECM terminal 56 and terminal 1. Refer to wiring diagram.
Continuity should exist.
3. Check harness continuity between ECM terminal 56 (or terminal 1) and ground. Refer to wiring diagram.
Continuity should not exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 5.
NG©GO TO 4.
DTC P0139 HO2S2KA24DE (EURO OBD)
Diagnostic Procedure
EC-3232

4 DETECT MALFUNCTIONING PART
Check the following.
+Harness for open or short between heated oxygen sensor 2 and ECM
©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK GROUND CIRCUIT
1. Check harness continuity between heated oxygen sensor 2 terminal 4 and engine ground. Refer to the Wiring Diagram.
Continuity should exist.
2. Also check harness for short to power.
OK or NG
OK (With CONSULT-II)©GO TO 7.
OK (Without CONSULT-
II)©GO TO 8.
NG©GO TO 6.
6 DETECT MALFUNCTIONING PART
Check the following.
+Joint connector-3
+Harness for open or short between heated oxygen sensor 2 and engine ground
©Repair open circuit or short to power in harness or connectors.
DTC P0139 HO2S2KA24DE (EURO OBD)
Diagnostic Procedure
EC-3233

7 CHECK HEATED OXYGEN SENSOR 2
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and drive vehicle at a speed of more than 70 km/h (43 MPH) for 2 consecutive minutes.
3. Stop vehicle with engine running.
4. Select ªFUEL INJECTIONº in ªACTIVE TESTº mode, and select ªHO2S2 (B1)º as the monitor item with CONSULT-II.
5. Check ªHO2S2 (B1)º at idle speed when adjusting ªFUEL INJECTIONº to±25%.
SEF662Y
ªHO2S2 (B1)º should be above 0.56V at least once when the ªFUEL INJECTIONº is +25%. ªHO2S2 (B1)º should
be below 0.54V at least once when the ªFUEL INJECTIONº is þ25%.
CAUTION:
+Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto
a hard surface such as a concrete floor; use a new one.
+Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner
tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
SEF244YD
OK or NG
OK©GO TO 9.
NG©Replace heated oxygen sensor 2.
DTC P0139 HO2S2KA24DE (EURO OBD)
Diagnostic Procedure
EC-3234

8 CHECK HEATED OXYGEN SENSOR 2
Without CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and drive vehicle at a speed of more than 70 km/h (43 MPH) for 2 consecutive minutes.
3. Stop vehicle with engine running.
4. Set voltmeter probes between ECM terminals 56 (Heated oxygen sensor 2 signal) and engine ground.
AEC874A
5. Check the voltage when revving up to 4,000 rpm under no load at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.56V at least once.
If the voltage is above 0.56V at step 4, step 5 is not necessary.
6. Check the voltage when revving up to 5,000 rpm under no load. Or keep vehicle at idling for 10 minutes, then check
the voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in 3rd gear position (M/T), ªDº position with
ªODº OFF (A/T).
The voltage should be below 0.54V at least once.
CAUTION:
+Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto
a hard surface such as a concrete floor; use a new one.
+Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner
tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
OK or NG
OK©GO TO 9.
NG©Replace heated oxygen sensor 2.
9 CHECK SHIELD CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect joint connector-3.
3. Check harness continuity between joint connector-3 terminal 1 and ground. Refer to wiring diagram.
Continuity should exist.
4. Also check harness for short to power.
5. Then reconnect harness connectors.
OK or NG
OK©GO TO 11.
NG©GO TO 10.
10 DETECT MALFUNCTIONING PART
Check the following.
+Joint connector-3 (Refer to ªHARNESS LAYOUTº, EL section.)
+Harness for open or short between joint connector-3 and engine ground
©Repair open circuit, short to power in harness or connectors.
DTC P0139 HO2S2KA24DE (EURO OBD)
Diagnostic Procedure
EC-3235

11 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3123.
©INSPECTION END
DTC P0139 HO2S2KA24DE (EURO OBD)
Diagnostic Procedure
EC-3236

On Board Diagnosis LogicNEEC0188With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensor 1. The ECM
calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MI (2 trip detection logic).
Sensor Input Signal to ECMECM func-
tionActuator
Heated oxygen sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injec-
tion & mix-
ture ratio
controlInjectors
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0171
0171+Fuel injection system does not operate properly.
+The amount of mixture ratio compensation is too large.
(The mixture ratio is too lean.)+Intake air leaks
+Heated oxygen sensor 1
+Injectors
+Exhaust gas leaks
+Incorrect fuel pressure
+Lack of fuel
+Mass air flow sensor
+Incorrect PCV hose connection
SEF215Z
SEF058Y
DTC Confirmation ProcedureNEEC0189NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch OFF and wait at least 5 seconds before
conducting the next test.
With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch OFF and wait at least 5 seconds.
3) Turn ignition switch ON and select ªSELF-LEARNING CONTº
in ªWORK SUPPORTº mode with CONSULT-II.
4) Clear the self-learning control coefficient by touching ªCLEARº.
5) Select ªDATA MONITORº mode with CONSULT-II.
6) Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0171 should be detected at this stage, if a
malfunction exists. If so, go to ªDiagnostic Procedureº,
EC-3240.
7) If it is difficult to start engine at step 6, the fuel injection sys-
tem has a malfunction.
8) Crank engine while depressing accelerator pedal. If engine
starts, go to ªDiagnostic Procedureº, EC-3240. If engine does
not start, visually check for exhaust and intake air leak.
AEC131A
With GST
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch OFF and wait at least 5 seconds.
3) Disconnect mass air flow sensor harness connector. Then
restart and run engine for at least 3 seconds at idle speed.
4) Stop engine and reconnect mass air flow sensor harness con-
nector.
5) Select ªMODE 7º with GST. Make sure DTC P0102 is detected.
6) Select ªMODE 4º with GST and erase the DTC P0102.
7) Start engine again and run it for at least 10 minutes at idle
speed.
DTC P0171 FUEL INJECTION SYSTEM
FUNCTION
KA24DE (EURO OBD)
On Board Diagnosis Logic
EC-3237

8) Select ªMODE 7º with GST. The 1st trip DTC P0171 should be
detected at this stage, if a malfunction exists. If so, go to
ªDiagnostic Procedureº, EC-3240.
9) If it is difficult to start engine at step 8, the fuel injection sys-
tem has a malfunction.
10) Crank engine while depressing accelerator pedal. If engine
starts, go to ªDiagnostic Procedureº, EC-3240. If engine does
not start, visually check for exhaust and intake air leak.
DTC P0171 FUEL INJECTION SYSTEM
FUNCTION
KA24DE (EURO OBD)
DTC Confirmation Procedure
EC-3238

Wiring DiagramNEEC0190
GEC296A
DTC P0171 FUEL INJECTION SYSTEM
FUNCTION
KA24DE (EURO OBD)
Wiring Diagram
EC-3239