INFINITI QX4 2001 Factory Service Manual

SEF359X
Overall Function Check=NBEC0372Use this procedure to check the overall function of the park/neutral
position (PNP) switch circuit. During this check, a 1st trip DTC
might not be confirmed.
WITH GSTNBEC0372S011) Turn ignition switch ªONº.
2) Check voltage between ECM terminal 44 and body ground
under the following conditions.
Condition (Gear position) Voltage V (Known good data)
ªPº and ªNº position Approx. 0
Except the above position Battery voltage
3) If NG, go to ªDiagnostic Procedureº, EC-608.
DTC P1706 PARK/NEUTRAL POSITION (PNP) SWITCH
Overall Function Check
EC-606

Wiring DiagramNBEC0373
MEC973C
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DTC P1706 PARK/NEUTRAL POSITION (PNP) SWITCH
Wiring Diagram
EC-607

Diagnostic ProcedureNBEC0374
1 CHECK PNP SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect park/neutral position (PNP) switch harness connector.
SEF011SA
3. Check harness continuity between PNP switch terminal 1 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to power.
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check harness for open or short between park/neutral position (PNP) switch and engine ground.
©Repair open circuit or short to power in harness or connectors.
3 CHECK PNP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 44 and PNP switch 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©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F22, M33 and M70, B50
IHarness for open or short between ECM and park/neutral position (PNP) switch
©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK PARK/NEUTRAL POSITION (PNP) SWITCH
Refer to AT-115, ªDiagnostic Procedureº.
OK or NG
OK©GO TO 6.
NG©Replace park/neutral position (PNP) switch.
DTC P1706 PARK/NEUTRAL POSITION (PNP) SWITCH
Diagnostic Procedure
EC-608

6 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION ENDGI
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DTC P1706 PARK/NEUTRAL POSITION (PNP) SWITCH
Diagnostic Procedure (Cont'd)
EC-609

DescriptionNBEC0596SYSTEM DESCRIPTIONNBEC0596S01
Sensor Input Signal to ECMECM func-
tionActuator
Mass air flow sensor Amount of intake air
VIAS con-
trolVIAS control solenoid valve Throttle position sensor Throttle position
Closed throttle position Throttle valve idle position
Ignition switch Start signal
Crankshaft position sensor (POS) Engine speed (POS signal)
Crankshaft position sensor (REF) Engine speed (REF signal)
Engine coolant temperature sensor Engine coolant temperature
SEF447Z
When the engine is running at low or medium speed, the power
valve is fully closed. Under this condition, the effective suction port
length is equivalent to the total length of the intake manifold collec-
tor's suction port including the intake valve. This long suction port
provides increased air intake which results in improved suction
efficiency and higher torque generation.
The surge tank and one-way valve are provided. When engine is
running at high speed, the ECM sends the signal to the VIAS con-
trol solenoid valve. This signal introduces the intake manifold
vacuum into the power valve actuator and therefore opens the
power valve to two suction passages together in the collector.
Under this condition, the effective port length is equivalent to the
length of the suction port provided independently for each cylinder.
This shortened port length results in enhanced engine output with
reduced suction resistance under high speeds.
VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)
Description
EC-610

SEF018Z
COMPONENT DESCRIPTIONNBEC0596S02Power ValveNBEC0596S0201The power valve is installed in intake manifold collector and used
to control the suction passage of the variable induction air control
system. It is set in the fully closed or fully opened position by the
power valve actuator operated by the vacuum stored in the surge
tank. The vacuum in the surge tank is controlled by the VIAS con-
trol solenoid valve.
SEF019Z
VIAS Control Solenoid ValveNBEC0596S0202The VIAS control solenoid valve cuts the intake manifold vacuum
signal for power valve control. It responds to ON/OFF signals from
the ECM. When the solenoid is off, the vacuum signal from the
intake manifold is cut. When the ECM sends an ON signal the coil
pulls the plunger downward and feeds the vacuum signal to the
power valve actuator.
ECM Terminals and Reference ValueNBEC0684Specification 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)
16 Y/GVIAS control solenoid
valve[Engine is running]
IIdle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
IEngine speed is above 5,000 rpm.0 - 1.0V
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VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)
Description (Cont'd)
EC-611

Wiring DiagramNBEC0597
MEC990C
VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)
Wiring Diagram
EC-612

Diagnostic ProcedureNBEC0598
1 CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Perform ªVIAS SOL VALVEº in ªACTIVE TESTº mode with CONSULT-II.
3. Turn VIAS control solenoid valve ªONº and ªOFFº, and make sure that power valve actuator rod moves.
SEC304C
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Rev engine quickly up to above 5,000 rpm and make sure that power valve actuator rod moves.
SEF021Z
OK or NG
OK©INSPECTION END
NG©GO TO 2.
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VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)
Diagnostic Procedure
EC-613

2 CHECK VIAS CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
1. Stop engine.
2. Disconnect VIAS control solenoid valve harness connector.
SEF019Z
3. Turn ignition switch ªONº.
4. Check voltage between terminal 1 and ground with CONSULT-II or tester.
SEF603X
OK or NG
OK©GO TO 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M32, F23
I10A fuse
IHarness continuity between fuse and VIAS control solenoid valve
©Repair harness or connectors.
4 CHECK VIAS CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 16 and terminal 2. 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 5.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)
Diagnostic Procedure (Cont'd)
EC-614

5 RETEST OVERALL FUNCTION
1. Reconnect harness connectors disconnected.
2. Perform Test No. 1 again.
OK or NG
OK©INSPECTION END
NG©GO TO 6.
6 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
OK or NG
OK©Replace VIAS control solenoid valve as intake manifold collector assembly.
NG©Repair or replace harness or connectors.
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VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)
Diagnostic Procedure (Cont'd)
EC-615