CELICA GT (2000)
Fixing Code: P0446
My Celica's check engine light came on, when I checked the code it was P0446. I reset it, it came back after a couple of days. I replaced most of the vacuum hoses and reset, it came back.
I replaced the gas cap, it came back. All the easy stuff done the main suspect was now the VSV, Vacuum Switching Valve!
I purchased a used OEM VSV from eBay for $19.I put the car up on ramps and removed the aluminium heat shield. I have a smaller after market muffler, this allowed me enough access to replace the VSV.
With the original muffler in may be necessary to drop it down or remove it altogether, I was lucky. I VSV's retaining screw was both rusted and at a right angle to me, not affording enough access to unscrew it.
I used the rather desperate measure of prying it off with a flat bladed screwdriver!! This bent the mount a little and allowed me to screw the replacement on using a small wrench and screwdriver bit.
I put the hoses back on, sprayed the edge of the fuel tank with rust inhibitor and replaced the heat shield. I tested the old VSV on a 12V power supply, it did not close!
Tools and Parts used
- Safety Goggles
- 90910-12264 OEM Vacuum Switching Valve
- A Can of PB Blaster
- Husky 3/8 In. Extendable Wrench more
- 3/8 In. Torque Wrench
- 10mm socket
- 6 inch socket extension bar
- Various flat blade screwdrivers as levers!
Charcoal box with heat shield removed
Vacuum Switching Valve/Solenoid removed
Old and New 90910-12264 OEM Vacuum Switching Valve
New Vacuum Switching Valve fitted
Hoses back on!
VSV Post Mortem
Having found that the VSV had definitely fail I broke it open to see why. The VSV is a Solenoid, it has a steel actuator rod sitting inside a copper coil, when electrical current flows through
the coil the resulting magnetic failed pushs the steel rod up, out of the coil. In the VSV the is a small spring on top of the coil and above that a cup shaped piece of metal which when pushed up closes the valve.
The steel actuator and spring were rust free, but a small patch on rust had formed on the 'metal cup' causing the valve to become stuck open.
Opening the VSV
Seen from above..
The rust spot, point of failure
This page is ONLY to show what I did to my Celica!
I take NO responsibility for anything arising from information given here nor do I guarantee its correctness!