I keep getting this code on my 01 4Runner which means;
"P0446
When the vapor pressure rises to a specified point, the ECM opens the VSV for CCV. Pressure will increase
rapidly because of the air allowed into the system. No increase or an increase below specified rate of pressure
increase indicates a restriction on the air inlet side.
The ECM closes the VSV for pressure switching valve. This action blocks air entering the fuel tank side of
system. The pressure rise on the fuel tank side is no longer as great.
If there was no change in pressure, the ECM will conclude the VSV for pressure switching valve did not close."
I don't really understand what's going on there, but the most common reason for this code seems to be a gas cap that is loose or cracked. I've looked at the cap and it and the gasket seem to be good. I've put the cap on securely and reset the code but it comes back, but not for a while. The last time I did this I had a full tank and the code didn't come back until the tank was down to a quarter. The next step seem to be testing the VSV(?) but the procedure uses a hand tester to control the VSV, can I find the problem with out having one of these?
"P0446
When the vapor pressure rises to a specified point, the ECM opens the VSV for CCV. Pressure will increase
rapidly because of the air allowed into the system. No increase or an increase below specified rate of pressure
increase indicates a restriction on the air inlet side.
The ECM closes the VSV for pressure switching valve. This action blocks air entering the fuel tank side of
system. The pressure rise on the fuel tank side is no longer as great.
If there was no change in pressure, the ECM will conclude the VSV for pressure switching valve did not close."
I don't really understand what's going on there, but the most common reason for this code seems to be a gas cap that is loose or cracked. I've looked at the cap and it and the gasket seem to be good. I've put the cap on securely and reset the code but it comes back, but not for a while. The last time I did this I had a full tank and the code didn't come back until the tank was down to a quarter. The next step seem to be testing the VSV(?) but the procedure uses a hand tester to control the VSV, can I find the problem with out having one of these?
I'm just saying start with the easy stuff.