How i repair the 446 code - 1996 Chevrolet Blazer

Hi there:
DTC P0446 - Evaporative Emmission Control System Vent Control Circuit
Evap vent valve has only one purpose. It closes in order to seal the vent so the EVAP system can pressurize and ensure there are no leaks. Evap vent valve is usually supplied Batt. voltage with key on. The ECM's driver controls the ground, and when grounded, activates the valve (closing it). If the ECM detects a short to ground, and open,or a short to battery voltage on the control circuit, P0446 will set.

With a P0446 OBD-II trouble code, here are some things to try:
Replace Vent valve
Repair open, short, or resistance problem in control circuit
Repair open, or short, or resistance problem in power circuit
Replace PCM

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