2001 NISSAN PICK-UP check engine

SEF484YE
On Board Diagnosis LogicNEEC1050The ECM monitors the switching frequency ratio of heated oxygen
sensor 1 and 2.
A three way catalyst with high oxygen storage capacity will indicate
a low switching frequency of heated oxygen sensor 2. As oxygen
storage capacity decreases, the heated oxygen sensor 2 switching
frequency will increase.
When the frequency ratio of heated oxygen sensors 1 and 2
approaches a specified limit value, the three way catalyst malfunc-
tion is diagnosed.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0420
0420+Three way catalyst does not operate properly.
+Three way catalyst does not have enough oxygen stor-
age capacity.+Three way catalyst
+Exhaust tube
+Intake air leaks
+Injectors
+Injector leaks
+Spark plug
+Improper ignition timing
PBIB0566E
PBIB0567E
DTC Confirmation ProcedureNEEC1051NOTE:
If ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
5 seconds before conducting the next test.
TESTING CONDITION:
+Open engine hood before conducting following proce-
dure.
+Do not hold engine speed more than specified minutes
below.
With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDTC & SRT CONFIRMATIONº then ªSRT WORK SUP-
PORTº mode with CONSULT-II.
3) Start engine.
4) Rev engine up to 2,500 to 3,500 rpm and hold it for 3 consecu-
tive minutes then release then accelerator pedal completely.
If ªINCMPº of ªCATALYSTº changes to ªCMPLTº, go to step 7.
5) Wait 5 seconds at idle.
6) Rev engine up to 2,500 to 3,500 rpm and hold it until ªINCMPº
of ªCATALYSTº changes to ªCMPLTº. (It will take maximum of
approximately 5 minute.)
SEF560X
7) Select ªSELF-DIAG RESULTSº mode with CONSULT-II.
If the 1st trip DTC is detected, go to ªDIAGNOSTIC
PROCEDUREº, EC-3280. If not ªCOMPLTº stop engine and
cool down ªCOOLANT TEMP/SEº to less than 70ÉC (158ÉF)
and then retest from step 1).
DTC P0420 THREE WAY CATALYST
FUNCTION
KA24DE (EURO OBD)
On Board Diagnosis Logic
EC-3278

AEC876A
Overall Function CheckNEEC0242Use this procedure to check the overall function of the three way
catalyst. During this check, a 1st trip DTC might not be confirmed.
Without CONSULT-II
1) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes.
2) Stop vehicle with engine running.
3) Set voltmeters probes between ECM terminals 50 (Heated
oxygen sensor 1 signal), 56 (Heated oxygen sensor 2 signal)
and engine ground.
4) Keep engine speed at 2,000 rpm constant under no load.
5) Make sure that the voltage switching frequency (high & low)
between ECM terminal 56 and engine ground is much less
than that of ECM terminal 50 and engine ground.
Switching frequency ratio = A/B
A: Heated oxygen sensor 2 voltage switching frequency
B: Heated oxygen sensor 1 voltage switching frequency
This ratio should be less than 0.75.
If the ratio is greater than above, it means three way catalyst
does not operate properly.
NOTE:
If the voltage at terminal 50 does not switch periodically more
than 5 times within 10 seconds at step 4, perform trouble
diagnosis for DTC P0133 first. (See EC-3202.)
DTC P0420 THREE WAY CATALYST
FUNCTION
KA24DE (EURO OBD)
Overall Function Check
EC-3279

Diagnostic Procedure=NEEC0243
1 CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
OK or NG
OK©GO TO 2.
NG©Repair or replace.
2 CHECK EXHAUST AIR LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust air leak before three way catalyst.
SEF099P
OK or NG
OK©GO TO 3.
NG©Repair or replace.
3 CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK©GO TO 4.
NG©Repair or replace.
4 CHECK IGNITION TIMING
1. Check the following items. Refer to ªBasic Inspectionº, EC-3086.
MTBL1315
OK or NG
OK©GO TO 5.
NG©Adjust ignition timing.
DTC P0420 THREE WAY CATALYST
FUNCTION
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3280

5 CHECK INJECTORS
1. Refer to Wiring Diagram for Injectors, EC-3370.
2. Stop engine and then turn ignition switch ON.
3. Check voltage between ECM terminals 102, 104, 109 and 111 and ground with CONSULT-II or tester.
LEC041A
Battery voltage should exist.
OK or NG
OK©GO TO 6.
NG©Perform ªDiagnostic Procedureº INJECTOR, EC-3371.
6 CHECK IGNITION SPARK
1. Disconnect ignition wire from spark plug.
2. Connect a known good spark plug to the ignition wire.
3. Place end of spark plug against a suitable ground and crank engine.
4. Check for spark.
SEF282G
OK or NG
OK©GO TO 8.
NG©GO TO 7.
DTC P0420 THREE WAY CATALYST
FUNCTION
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3281

4 DETECT MALFUNCTIONING PART
Check the harness for open or short between EVAP canister purge volume control solenoid valve and ECM.
©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
1. Start engine.
2. Perform ªPURG VOL CONT/Vº in ªACTIVE TESTº mode with CONSULT-II. Check that engine speed varies according
to the valve opening.
SEF801Y
OK or NG
OK©GO TO 7.
NG©GO TO 6.
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3288

SEF505U
Component DescriptionNEEC0272The vehicle speed sensor is installed in the transmission. It con-
tains a pulse generator which provides a vehicle speed signal to
the speedometer. The speedometer then sends a signal to the
ECM.
ECM Terminals and Reference ValueNEEC0273Specification 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 result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
29 W/L Vehicle speed sensor[Engine is running]
+Lift up the vehicle
+In 2nd gear position
+Vehicle speed is 40 km/h (25 MPH)1-4V
SEF003W
On Board Diagnosis LogicNEEC0274
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0500
0500+The almost 0 km/h (0 MPH) signal from vehicle speed
sensor is sent to ECM even when vehicle is being
driven.+Harness or connector
(The vehicle speed sensor circuit is open or
shorted.)
+Vehicle speed sensor
DTC Confirmation ProcedureNEEC0275CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch OFF and wait at least 5 seconds before
conducting the next test.
TESTING CONDITION:
This procedure may be conducted with the drive wheels lifted
in the shop or by driving the vehicle. If a road test is expected
to be easier, it is unnecessary to lift the vehicle.
DTC P0500 VSSKA24DE (EURO OBD)
Component Description
EC-3290

SEF196Y
With CONSULT-II
1) Start engine
2) Read vehicle speed sensor signal in ªDATA MONITORº mode
with CONSULT-II. The vehicle speed on CONSULT-II should
exceed 10 km/h (6 MPH) when rotating wheels with suitable
gear position.
3) If NG, go to ªDiagnostic Procedureº, EC-3294.
If OK, go to following step.
4) Select ªDATA MONITORº mode with CONSULT-II.
5) Warm engine up to normal operating temperature.
6) Maintain the following conditions for at least 1 minute.
ENG SPEED 1,800 - 6,000 rpm
COOLAN TEMP/S More than 70ÉC (158ÉF)
B/FUEL SCHDL 7 - 15 msec
Selector lever Suitable position
PW/ST SIGNAL OFF
7) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-3294.
SEF568P
Overall Function CheckNEEC0276Use this procedure to check the overall function of the EVAP can-
ister vent control valve circuit. During this check, a 1st trip DTC
might not be confirmed.
With GST
1) Lift up drive wheels.
2) Start engine.
3) Read vehicle speed sensor signal in ªMODE 1º with GST.
The vehicle speed sensor on GST should be able to exceed
10 km/h (6 MPH) when rotating wheels with suitable gear posi-
tion.
4) If NG, go to ªDiagnostic Procedureº, EC-3294.
DTC P0500 VSSKA24DE (EURO OBD)
DTC Confirmation Procedure
EC-3291

ECM Terminals and Reference Value=NEEC1596Specification 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 result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
101 G/Y IACV-AAC valve[Engine is running]
+Warm-up condition
+Idle speed10.5 - 11.5V
SEF015W
[Engine is running]
+Warm-up condition
+Engine speed is 2,000 rpm1 - 13V
SEF016W
On Board Diagnosis LogicNEEC1597
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0505
0505A) The IACV-AAC valve does not operate properly.+Harness or connectors
(The IACV-AAC valve circuit is open.)
+IACV-AAC valve
B) The IACV-AAC valve does not operate properly.+Harness or connectors
(The IACV-AAC valve circuit is shorted.)
+IACV-AAC valve
DTC P0505 ISC SYSTEMKA24DE (EURO OBD)
ECM Terminals and Reference Value
EC-3296