01 Corolla P0446

I’m going to start by warning you that I’m at work and at the mercy of computers that suck to access Alldata, which is a reference database that sucks at providing factory service information that sucks for anybody who appreciates plain english. And lastly, my shop has a OTC Genisys Touch scan tool that may as well just suck rancid goat dick. It can barely power itself up let alone command something as simple as a vent solenoid closed. If you’re in the market to buy your own fancy schmancy scan tool, do not buy a Genisys Touch unless you need a worthless scan tool designed to specifically suck rancid goat dick. Anyway….

The code was defined as a evap vent solenoid circuit fault with a hand held code reader. So I switch over to the Genisys so I can command the solenoid open & closed. Or so I thought. I try to command solenoids on & off and the Genisys failed in enough ways that I had no idea whether or not it even tried doing what I told it to before it aborted testing. I never heard a solenoid click once.

At this point, I decide to try voltage drop testing at what I thought was the vent solenoid. (I really hate reading Toyota service information and wiring diagrams so I make that my last resort.) The solenoid I’m chasing is on the canister & it’s got a black and red wire connected to it. I’m looking at voltages with the pigtail disconnected from the solenoid at this point. The black wire is providing power and shows battery voltage with negative test lead grounded to the chassis. I move the negative lead to the red wire at the connector and I go from battery voltage to 2.57 volts. So I feel really good I’ve got a ground wire problem. I reconect the pigtail to the solenoid and I find battery voltage going to and through the solenoid. Now I feel really good about a ground wire problem. I chase the harness up along the floor pan and find a spot just shy of the A pillar and stab the wire and I still have battery voltage that far.

Now I have to go to the service information to find out where the ECM is hidden and learn it’s buried under the center console. I ran out of time to dig that far into the dash. In looking the car over and doing some other reading here at home, I just can’t see there being a problem at the ECM or the rest of that wiring. What’s worse is I no longer have any idea what solenoid I’ve been poking at all this time.

Instead of doing things simple like vent and purge valves like the rest of the industry, Toyota gives me VSV for CCV, VSV for EVAP, and VSV for pressure switching valves. In reading through the shitty diag charts, I inferred that the VSV for EVAP is the purge solenoid. My wiring diagram says the circuit I was chasing is for the VSV pressure switching valve. I learned that CCV means canister closed valve. I’d think that means it’s a vent solenoid and I’ve missed the thing I wanted to diagnose altogether.

I’ve got to tackle this car again tomorrow and I’m bringing in my Modis so I can maybe get something useful done. I’ve already looked at Identifix too, and it shows heavy hits to replace the canister, but really anything is possible with the other solenoids too. What I’m hoping for before then, is some thoughts on my voltage drops on the circuit I did test. A clue where the CCV solenoid would be at would be awesome. Any constructive thoughts or critisisms would be appreciated.

Thanks for reading.