DTC p0446, where is the vent solenoid located? 99 lesabre
The Trouble Code PO446 is typically a high pressure in Fuel Tank, which can be caused by the Vent Solenoid or blockage at the Tank
Here is Buick procedures
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Use of Scan Tool is needed:
If an EVAP vent valve or EVAP purge valve electrical malfunction is present, the purge system will not operate correctly.
Repairing the electrical malfunction that caused the additional DTC to set will very likely correct the condition that set this DTC.
Checks for a fuel tank pressure sensor stuck high condition.
The scan tool should read within 1.0 in. H20 of the specified value.
Verifies that the fuel tank pressure sensor accurately reacts to EVAP system pressure changes.
The EVAP station is pressurizing a sensor that normally reads vacuum.
The Tech II Scan Tool reads high pressure at 0 Volts and high vacuum at 5 Volts.
The Tech II can only read a maximum pressure of 6.0 in. of H20 (0 Volts).
However the EVAP Service Station can pressurize the system to much higher pressures.
The Scan Tool value should be within 0.5 of the specified value.
Checks for a plugged or stuck closed EVAP Vent valve/solenoid.
The value should decrease to within 1.0 in. HG of the specified value.