engine INFINITI QX4 2001 Factory Service Manual
[x] Cancel search | Manufacturer: INFINITI, Model Year: 2001, Model line: QX4, Model: INFINITI QX4 2001Pages: 2395, PDF Size: 43.2 MB
Page 1026 of 2395

On Board Diagnosis LogicNBEC0282HThe closed loop control has the one trip detection logic.
Malfunction is detected when the closed loop control function for
right bank does not operate even when vehicle is driving in the
specified condition, the closed loop control function for left bank
does not operate even when vehicle is driving in the specified
condition.
Possible CauseNBEC0531IThe front heated oxygen sensor circuit is open or shorted.
IHeated oxygen sensor 1 (front)
IHeated oxygen sensor 1 heater (front)
DTC Confirmation ProcedureNBEC0283CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
INever raise engine speed above 3,600 rpm during the
ªDTC Confirmation Procedureº. If the engine speed limit is
exceeded, retry the procedure from step 2.
IBefore performing the following procedure, confirm that
battery voltage is more than 11V at idle.
SEF063Y
WITH CONSULT-IINBEC0283S011) Start engine and warm it up to normal operating temperature.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Hold engine speed at 2,000 rpm and check one of the follow-
ing.
IªHO2S1 (B1)/(B2)º voltage should go above 0.70V at least
once.
IªHO2S1 (B1)/(B2)º voltage should go below 0.21V at least
once.
If the check result is NG, perform ªDiagnosis Procedureº,
EC-492.
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DTC P1148 (RIGHT BANK, -B1), P1168 (LEFT BANK, -B2) CLOSED LOOP
CONTROL
On Board Diagnosis Logic
EC-491
Page 1027 of 2395

If the check result is OK, perform the following step.
4) Let engine idle at least 5 minutes.
5) Maintain the following condition at least 50 consecutive sec-
onds.
B/FUEL SCHDL 3.6 msec or more
ENG SPEED 1,500 rpm or more
Selector lever Suitable position
VHCL SPEED SE More than 70 km/h (43 MPH)
During this test, P0130 and/or P0150 may be displayed on
CONSULT-II screen.
6) If DTC is detected, go to ªDiagnostic Procedureº, EC-492.
SEF308XB
Overall Function CheckNBEC0284Use this procedure to check the overall function of the closed loop
control. During this check, a DTC might not be confirmed.
WITH GSTNBEC0284S011) Start engine and warm it up to normal operating temperature.
2) Set voltmeter probes between ECM terminal 63 [Heated oxy-
gen sensor 1 (front) right bank signal] or 62 [Heated oxygen
sensor 1 (front) left bank signal] and engine ground.
3) Check the following with engine speed held at 2,000 rpm con-
stant under no-load.
IThe voltage should go above 0.70V at least once.
IThe voltage should go below 0.21V at least once.
4) If NG, go to ªDiagnostic Procedureº, EC-492.
Diagnostic ProcedureNBEC0285Perform trouble diagnosis for ªDTC P0133, P0153º, EC-218.
DTC P1148 (RIGHT BANK, -B1), P1168 (LEFT BANK, -B2) CLOSED LOOP
CONTROL
DTC Confirmation Procedure (Cont'd)
EC-492
Page 1028 of 2395

SEF999Y
Component DescriptionNBEC0532The swirl control valve control vacuum check switch detects
vacuum signal to the swirl control valve, and sends ªONº or ªOFFº
signal to the ECM.
When vacuum is supplied to the valve, the swirl control valve con-
trol vacuum check switch sends ªOFFº signal to the ECM.
The swirl control valve control vacuum check switch is not used to
control the engine system, it is used for on board diagnosis.
SEF446Z
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0533Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
SWL CON VC SWIEngine speed: Idle
IEngine coolant temperature is between 15ÉC (59ÉF) to 50ÉC (122ÉF).OFF
IEngine speed: Idle
IEngine coolant temperature is above 55ÉC (131ÉF).ON
ECM Terminals and Reference ValueNBEC0674Specification 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)
55 W/BSwirl control valve con-
trol vacuum check
switch[Engine is running]
IIdle speed
IEngine coolant temperature is between 15 to
50ÉC (59 to 122ÉF).Approximately 5V
[Engine is running]
IIdle speed
IEngine coolant temperature is above 55ÉC
(122ÉF).0 - 1.0V
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DTC P1165 SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
Component Description
EC-493
Page 1029 of 2395

On Board Diagnosis LogicNBEC0535Malfunction is detected when the swirl control valve control vacuum
check switch remains ªOFFº under specified engine conditions.
Possible CauseNBEC0536IHarness or connectors
(Swirl control valve control vacuum check switch circuit is
open.)
IHoses
(Hoses are clogged or connected incorrectly.)
ISwirl control valve control solenoid valve
ISwirl control valve control vacuum check switch
SEF058Y
DTC Confirmation ProcedureNBEC0537NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
For best results, perform the test at a temperature above 5ÉC
(41ÉF).
WITH CONSULT-IINBEC0537S011) Turn ignition switch ªOFFº and wait at least 10 seconds.
2) Turn ignition switch ªONº.
3) Select ªDATA MONITORº mode with CONSULT-II and wait at
least 5 seconds.
If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-496.
WITH GSTNBEC0537S02Follow the procedure ªWITH CONSULT-IIº above.
DTC P1165 SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
On Board Diagnosis Logic
EC-494
Page 1031 of 2395

Diagnostic ProcedureNBEC0539
1 CHECK HOSES
1. Turn ignition switch ªOFFº.
2. Check hose for clogging or improper connection.
SEF109L
OK or NG
OK©GO TO 2.
NG©Repair or reconnect the hose.
2 CHECK SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH GROUND CIRCUIT FOR OPEN
AND SHORT
1. Disconnect swirl control valve control vacuum check switch harness connector.
SEF999Y
2. Check harness continuity between terminal 2 and ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OK©GO TO 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E1, M1 and M92, F27
IHarness for open between swirl control valve control vacuum check switch and engine ground
©Repair open circuit or short to power in harness connectors.
DTC P1165 SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
Diagnostic Procedure
EC-496
Page 1033 of 2395

6 CHECK SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
With CONSULT-II
1. Reconnect the disconnected harness connectors.
2. Start engine and let it idle.
3. Remove vacuum hose connected to swirl control valve actuator.
4. Select ªSWIRL CONT SOL/Vº in ªACTIVE TESTº mode with CONSULT-II.
5. Touch ªONº and ªOFFº on CONSULT-II screen.
6. Check vacuum existence and operation delay time under the following conditions.
SEF004Z
Without CONSULT-II
1. Reconnect ECM harness connector.
2. Remove vacuum hose connected to swirl control valve actuator.
3. Start engine and let it idle.
4. Apply 12V of direct current between swirl control valve control solenoid valve terminals and 2.
5. Check vacuum existence and operation delay time under the following conditions.
SEF005Z
OK or NG
OK©GO TO 7.
NG©Replace intake manifold collector assembly.
7 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
DTC P1165 SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
Diagnostic Procedure (Cont'd)
EC-498
Page 1034 of 2395

Component DescriptionNBEC0286IGNITION COIL & POWER TRANSISTORNBEC0286S01The ignition signal from the ECM is sent to and amplified by the power transistor. The power transistor turns
on and off the ignition coil primary circuit. This on-off operation induces the proper high voltage in the coil
secondary circuit.
SEF975Y
ECM Terminals and Reference ValueNBEC0675Specification 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)
21
22
23
30
31
32Y/R
G/R
L/R
GY
PU/W
GY/RIgnition signal No. 1
Ignition signal No. 2
Ignition signal No. 3
Ignition signal No. 4
Ignition signal No. 5
Ignition signal No. 6[Engine is running]
IWarm-up condition
IIdle speed0 - 0.2VH
SEF399T
[Engine is running]
IWarm-up condition
IEngine speed is 2,500 rpm.0.1 - 0.3VH
SEF645T
H: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
On Board Diagnosis LogicNBEC0288Malfunction is detected when the ignition signal in the primary cir-
cuit is not sent to ECM during engine cranking or running.
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DTC P1320 IGNITION SIGNAL
Component Description
EC-499
Page 1035 of 2395

Possible CauseNBEC0572IHarness or connectors (The ignition primary circuit is open or
shorted.)
IPower transistor unit built into ignition coil
ICondenser
ICrankshaft position sensor (REF)
ICrankshaft position sensor (REF) circuit
SEF058Y
DTC Confirmation ProcedureNBEC0289NOTE:
IIf ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
10 seconds before conducting the next test.
IIf DTC P1320 is displayed with DTC P0335, P0340, P1335
or P1336, perform trouble diagnosis for DTC P0335,
P0340, P1335 or P1336 first. Refer to EC-334, EC-342,
EC-510 or EC-517.
WITH CONSULT-IINBEC0289S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine. (If engine does not run, turn ignition switch to
ªSTARTº for at least 5 seconds.)
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-504.
WITH GSTNBEC0289S02Follow the procedure ªWITH CONSULT-IIº above.
DTC P1320 IGNITION SIGNAL
Possible Cause
EC-500
Page 1039 of 2395

Diagnostic ProcedureNBEC0291
1 CHECK ENGINE START
Turn ignition switch ªOFFº, and restart engine.
Is engine running?
YesorNo
Yes (With CONSULT-II)©GO TO 2.
Yes (Without CONSULT-
II)©GO TO 12.
No©GO TO 3.
2 SEARCH FOR MALFUNCTIONING CIRCUIT
With CONSULT-II
1. Perform ªPOWER BALANCEº in ªACTIVE TESTº mode with CONSULT-II.
2. Search for circuit which does not produce a momentary engine speed drop.
SEF190Y
©GO TO 12.
3 CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ON.
2. Check voltage between ECM terminals 110, 112 and ground with CONSULT-II or tester.
SEF366X
OK or NG
OK©GO TO 4.
NG©Go to TROUBLE DIAGNOSIS FOR POWER SUPPLY, EC-142.
DTC P1320 IGNITION SIGNAL
Diagnostic Procedure
EC-504
Page 1042 of 2395

10 CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between condenser terminal 2 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OK©GO TO 11.
NG©Repair open circuit or short to power in harness or connectors.
11 CHECK CONDENSER
Check resistance between condenser terminals 1 and 2.
SEF369X
OK or NG
OK©GO TO 12.
NG©Replace condenser.
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DTC P1320 IGNITION SIGNAL
Diagnostic Procedure (Cont'd)
EC-507