NISSAN TEANA 2003 Service Manual

REFRIGERANT PRESSURE SENSOR
EC-749
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC

Wiring DiagramBBS00570
TBWM0644E

EC-750
[VQ]
REFRIGERANT PRESSURE SENSOR

Specification 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.
Diagnostic ProcedureBBS00571
1. CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower fan switch ON.
3. Check voltage between ECM terminal 70 and ground with CON-
SULT-II or tester.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2. CHECK GROUND CONNECTIONS
1. Turn A/C switch and blower fan switch OFF.
2. Turn ignition switch OFF.
3. Loosen and retighten two ground screws on the body.
Refer to EC-457, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
49 BR/WSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
67 B Sensor ground[Engine is running]

Warm-up condition

Idle speedApproximately 0V
70 W Refrigerant pressure sensor[Engine is running]

Warm-up condition

Both A/C switch and blower fan switch: ON
(Compressor operates.)1.0 - 4.0V
Voltage: 1.0 - 4.0V
PBIB1188E
PBIB2160E

REFRIGERANT PRESSURE SENSOR
EC-751
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC

3. CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect refrigerant pressure sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between refrigerant pressure sensor terminal 1
and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E39, F41

Harness for open or short between ECM and refrigerant pressure sensor
>> Repair harness or connectors.
5. CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between refrigerant pressure sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E39, F41

Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
PBIB2112E
Voltage: Approximately 5V
PBIB0188E
Continuity should exist.

EC-752
[VQ]
REFRIGERANT PRESSURE SENSOR

7. CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 70 and refrigerant pressure sensor terminal 2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E39, F41

Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-450, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace refrigerant pressure sensor.
NG >> Repair or replace.
Removal and InstallationBBS00572
REFRIGERANT PRESSURE SENSOR
Refer to ATC-144, "Removal and Installation of Refrigerant Pressure Sensor" . Continuity should exist.

VIAS
EC-753
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC

VIASPFP:14956
DescriptionBBS00565
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
When the engine is running at medium speed, the ECM sends the ON signal to the VIAS control solenoid
valve. This signal introduces the intake manifold vacuum into the power valve actuator and therefore closes
the power valve.
Under this condition, the effective intake manifold length is equivalent to the total length of passage A and pas-
sage B. This long intake manifold provides increased amount of intake air, which results in improved suction
efficiency and higher torque.
When engine is running at low or high speed, the ECM sends the OFF signal to the VIAS control solenoid
valve and the power valve is opened.
Under this condition, the effective intake manifold length is equivalent to the length of passage B. This short-
ened intake manifold length results in enhanced engine output due to reduced suction resistance under high
speeds.
COMPONENT DESCRIPTION
Power Valve
The power valve is installed in intake manifold collector and used to
control the suction passage of the variable induction air control sys-
tem. 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 control solenoid
valve.
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
VIAS control VIAS control solenoid valve Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Battery Battery voltage*
PBIB1822E
PBIB2108E

EC-754
[VQ]
VIAS

VIAS Control Solenoid Valve
The 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.
CONSULT-II Reference Value in Data Monitor ModeBBS00566
Specification data are reference values.
PBIB2108E
MONITOR ITEM CONDITION SPECIFICATION
VIAS S/V

Engine: After warming up1,800 - 3,600 rpm (VQ35DE engine)
1,800 - 3,750 rpm (VQ23DE engine)ON
Except above conditions OFF

VIAS
EC-755
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC

Wiring DiagramBBS00567
TBWM1468E

EC-756
[VQ]
VIAS

Specification 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.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
29 Y/G VIAS control solenoid valve[Engine is running]

Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed:
Between 1,800 and 3,600 rpm
(VQ35DE engine)
Between 1,800 and 3,750 rpm
(VQ23DE engine)0 - 1.0V
111 W / BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]

More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 9
120R/G
R/GPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)

VIAS
EC-757
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC

Diagnostic ProcedureBBS00568
1. CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Perform “VIAS SOL VALVE” in “ACTIVE TEST” mode with CON-
SULT-II.
3. Turn VIAS control solenoid valve ON and OFF, and make sure
that power valve actuator rod moves.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Rev engine up to between 1,800 and 3,600 (VQ35DE), 3,750
(VQ23DE) rpm and make sure that power valve actuator rod
moves.
OK or NG
OK >>INSPECTION END
NG (With CONSULT-II) >>GO TO 2.
NG (Without CONSULT-II) >>GO TO 3.
PBIB0844E
PBIB2472E
PBIB2472E

EC-758
[VQ]
VIAS

2. CHECK VACUUM EXISTENCE
With CONSULT-II
1. Stop engine and disconnect vacuum hose connected to power valve actuator.
2. Start engine and let it idle.
3. Perform “VIAS SOL VALVE” in “ACTIVE TEST” mode with CONSULT-II.
4. Turn VIAS control solenoid valve ON and OFF, and check vac-
uum existence under the following conditions.
OK or NG
OK >> Repair or replace power valve actuator.
NG >> GO TO 4.
3. CHECK VACUUM EXISTENCE
Without CONSULT-II
1. Stop engine and disconnect vacuum hose connected to power valve actuator.
2. Disconnect VIAS control solenoid valve harness connector.
3. Start engine and let it idle.
4. Apply 12V of direct current between VIAS control solenoid valve
terminals 1 and 2.
5. Check vacuum existence under the following conditions.
OK or NG
OK >> Repair or replace power valve actuator.
NG >> GO TO 4.
4. CHECK VACUUM HOSE
1. Stop engine.
2. Check hoses and tubes between intake manifold and power
valve actuator for crack, clogging, improper connection or dis-
connection. Refer to EC-412, "
Vacuum Hose Drawing" .
OK or NG
OK >> GO TO 5.
NG >> Repair hoses or tubes.
VIAS SOL VALVE Vacuum
ON Should exist
OFF Should not exist
PBIB0844E
Condition Vacuum
12V direct current supply Should exist
No supply Should not exist
PBIB0845E
SEF109L