P0445

P0445 indicates the EVAP purge valve control circuit is shorted, meaning the PCM driver detected excessive current draw (short to ground on the control wire) or shorted coil windings. Cheapest checks: disconnect the valve and measure coil resistance; anything under roughly 15 ohms (well below the 22 to 30 ohm typical spec) confirms internally shorted windings. With the valve unplugged, check the control wire from valve to PCM for a short to ground using a multimeter on continuity mode between the control pin and chassis ground; resistance should read infinite/OL. If the wire is shorted to ground anywhere along its run, repair the chafe point (commonly where the harness crosses metal brackets or routes near exhaust heat shields). With a known-good valve installed and harness verified, command the valve with a scan tool and watch for the code to re-set; if it does, the PCM driver may be damaged from a prior short event, which sometimes requires PCM replacement or reprogramming. Caveat: replacing a purge valve without finding the original short-to-ground cause will often destroy the new valve and the PCM driver within minutes of operation, so always ohm the harness to ground before installing the replacement.

Vehicle-specific patterns: 2002 to 2009 Chevrolet/GMC full-size pickups with the V8 trip P0445 from the purge valve harness shorting against the intake manifold bolts, GM PIP4818 covers harness rerouting and updated valve. 2003 to 2008 Ford F-150 with 5.4L sets P0445 from the purge solenoid coil shorting internally after heat-soak. 2004 to 2008 Honda Pilot/Odyssey sets P0445 from canister purge valve shorted-winding failure on the engine-mounted unit. 2005 to 2010 Toyota Tundra/Sequoia with the 4.7L 2UZ trips the equivalent VSV-shorted code from internal coil failure, Toyota recommends VSV replacement. Estimated repair: $80 to $320.