Quest Minivan SE V6-3.3L (VG33E) (1999)
Fuel Tank Cut Valve: All Technical Service Bulletins
Emissions System - MIL ON/DTC P1491 (EVAP) Stored
Classification:
EC02-008
Reference:
NTB02-033
Date:
March 21, 2002
DTC 1491 (VACUUM CUT VALVE BYPASS VALVE) DIAGNOSIS
APPLIED VEHICLE(S):
1998-2002 All Models
SERVICE INFORMATION
This bulletin is an aid to the diagnostic procedures in the Service Manual for DTC P1491.
If one of the applied vehicles has the MIL "ON" with DTC P1491 (Vacuum Cut Valve Bypass Valve) stored in Self-Diagnostic Results, use the service
procedure in this bulletin and the appropriate Service Manual to help you diagnosis the incident, if it should occur.
SERVICE PROCEDURE
1.
Confirm the Vacuum Cut Valve is installed correctly (See Figure 1).
NOTE:
^
The Vacuum Cut Valve will not work correctly and a DTC will be stored if it is installed upside-down.
^
The Vacuum Cut Valve is a white plastic valve near the fuel tank and EVAP canister.
2.
Connect CONSULT-II and turn the ignition key to "N" (do not start the engine).
3.
On CONSULT II, select ENGINE - DATA MONITOR - SELECTION FROM MENU - EVAP SYSTEM PRESSURE SENSOR.
4.
Note the EVAP System Pressure Sensor Voltage Confirm that it is reading in a normal range for a key ON arid engine OFF condition.
NOTE:
For 2001 models and earlier:
^
Voltage in step 4 should be near 3.36 volts.
^
The normal range is between 3.32 - 3.40 volts.
For 2002 models: