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Home >> Nissan-Datsun >> 1998 >> Maxima GXE V6-3.0L (VQ30DE) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P1444 >> With CONSULT - Screen Terms

With CONSULT - Screen Terms





SYSTEM DESCRIPTION
This system automatically controls flow rate of fuel vapor from EVAP canister. The EVAP canister purge volume control valve changes the opening of the vapor by-pass passage to control the flow rate. This valve is actuated by a step motor built into the valve, which moves the valve in the axial direction in steps corresponding to the ECM output pulses, the opening of the valve is varied to allow for optimum engine control. The optimum value stored in the ECM is determined by taking into consideration various engine conditions. When the engine operates, the flow rate is proportionally regulated as the air flow increases.






COMPONENT DESCRIPTION
The EVAP canister purge volume control valve is operated by a step motor for control of flow rate of fuel vapor from EVAP canister. This motor has four winding phases and is actuated by the output pulse signal of ECM which turns ON and OFF two windings each in sequence. Each time the valve opens or closes to change the flow rate, an ON pulse is issued. When no change in the flow rate is needed, the valve remains at a certain opening, hence no pulse signal output is issued.






CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Specification data are reference values.






ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values, and are measured between each terminal and (25) (ECCS ground).






ON BOARD DIAGNOSIS LOGIC


DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

CAUTION: Always drive vehicle at a safe speed.

NOTE:
- If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.
- This test 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.

TESTING CONDITION:
Always perform test at a temperature of 5°C (41°F) or more.















With CONSULT
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch "OFF" and wait at least 5 seconds.
3) Turn ignition switch "ON".
4) Select "PURG CN/V & S/V P1493" of "EVAPORATIVE SYSTEM" in "DTC WORK SUPPORT" mode with CONSULT.
5) Touch "START".
6) Start engine and let it idle for at least 50 seconds.
7) When the following conditions are met, "TESTING" will be displayed on the CONSULT screen. Maintain the conditions continuously until "TESTING" changes to "COMPLETED". (It will take for at least 30 seconds.)

Selector lever: Suitable position
Vehicle speed: 30 - 100 km/h (19 - 62 MPH)
CKPS-RPM (POS): 1,000 - 3,000 rpm
B/FUEL SCHDL: 1.0- 4.5 ms

8) Stop vehicle with engine running.
9) Select "PURG VOL C/V P1444" of "EVAPORATIVE SYSTEM" in "DTC WORK SUPPORT" mode with CONSULT.
10) Touch "START".

If "COMPLETED" is displayed, go to step 12).

11) When the following conditions are met, "TESTING" will be displayed on the CONSULT screen. Maintain the conditions continuously until "TESTING" changes to "COMPLETED". (It will take for at least 10 seconds.)

Selector lever: Suitable position
Vehicle speed: 30 - 100 km/h (19 - 62 MPH)
CKPS-RPM (POS): 1,000 - 3,000 rpm
B/FUEL SCHDL: 1.0- 4.5 ms

If "TESTING" is not displayed after 5 minutes, retry from step 2).

12) Make sure that "OK" is displayed after touching "SELF-DIAG RESULTS". If "NG" is displayed, refer to "DIAGNOSTIC PROCEDURE".







DIAGNOSTIC PROCEDURE


COMPONENT INSPECTION
EVAP canister purge volume control valve









With CONSULT
1. Disconnect EVAP canister purge volume control valve harness connector.
2. Check resistance between the following terminals.
terminal (2) and terminals (1), (3)
terminal (5) and terminals (4), (6)

Resistance: Approximately 30 Ohms [At 25°C (77°F)]

3. Reconnect EVAP canister purge volume control valve harness connector.
4. Remove EVAP canister purge volume control valve from intake manifold collector and disconnect hoses from the valve.
(Plug the purge hoses. The EVAP canister purge volume control valve harness connector should remain connected.)

5. Turn ignition switch "ON".
6. Perform "PURG VOL CONT/V" in "ACTIVE TEST" mode with CONSULT and ensure the EVAP canister purge volume control valve shaft smoothly moves forward and backward according to the valve opening.
If NG, replace the EVAP canister purge volume control valve.










EVAP control system pressure sensor
1. Remove EVAP control system pressure sensor with its harness connector connected.
2. Remove hose from EVAP control system pressure sensor.
3. Use pump to apply vacuum and pressure to EVAP control system pressure sensor as shown in figure.
4. Check output voltage between ECM terminal (62) and (25) (ECM ground).

CAUTION:
- Always calibrate the vacuum pump gauge when using it.
- Do not apply below -20 kPa (-150 mmHg, -5.91 inHg) or over 20 kPa (150 mmHg, 5.91 inHg) of pressure.

5. If NG, replace EVAP control system pressure sensor.


EVAP canister vent control valve
Check air passage continuity.









With CONSULT
Perform "VENT CONTROL/V" in "ACTIVE TEST" mode with CONSULT.
If NG, clean valve using air blower or replace as necessary.
If the portion (B) is rusted, replace EVAP canister vent control valve.
Make sure new O-ring is installed properly.

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