IDX INFINITI QX4 2001 Factory Service Manual

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

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

Wiring DiagramNBEC0538
MEC981C
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DTC P1165 SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
Wiring Diagram
EC-495

4 CHECK SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH INPUT SIGNAL CIRCUIT FOR
OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 55 and swirl control valve control vacuum check switch terminal 1.
Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 5.
NG©Repair open circuit, short to ground or short to power in harness connectors.
5 CHECK SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
1. Turn ignition switch ªOFFº.
2. Disconnect vacuum hose connected to swirl control valve control vacuum check switch.
3. Attach vacuum pump to swirl control valve control vacuum check switch.
4. Turn ignition switch ªONº.
5. Check voltage between ECM terminal 55 and ground under the following conditions.
SEF709X
OK or NG
OK©GO TO 6.
NG©Replace swirl control valve control vacuum check switch.
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DTC P1165 SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
Diagnostic Procedure (Cont'd)
EC-497

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

Wiring DiagramNBEC0290
MEC969C
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DTC P1320 IGNITION SIGNAL
Wiring Diagram
EC-501

MEC971C
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DTC P1320 IGNITION SIGNAL
Wiring Diagram (Cont'd)
EC-503

4 CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
SEF008Z
3. Turn ignition switch ON.
4. Check voltage between condenser terminal 1 and ground with CONSULT-II or tester.
SEF367X
OK or NG
OK©GO TO 10.
NG©GO TO 5.
5 CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF.
2. Disconnect ECM relay.
SEF009Z
3. Check harness continuity between ECM relay terminal 3 and condenser terminal 1. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 7.
NG©GO TO 6.
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DTC P1320 IGNITION SIGNAL
Diagnostic Procedure (Cont'd)
EC-505

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

15 CHECK IGNITION COIL OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 21, 22, 23, 30, 31, 32 and ignition coil terminal 1. Refer to Wiring
Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 16.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
16 CHECK IGNITION COIL WITH POWER TRANSISTOR
Check resistance between ignition coil terminals 2 and 3.
SEF371X
OK or NG
OK©GO TO 17.
NG©Replace ignition coil with power transistor.
17 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
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DTC P1320 IGNITION SIGNAL
Diagnostic Procedure (Cont'd)
EC-509