2001 camry buzzing in rear

[dvp59]

Our camry is buzzing in the rear at hwy speed.It seems to be from the canister area? I blew out the relay on the top of canister with compressed air and it seems to hold pressure.We sometimes get the 440 code. Does anyone know which relay controls cutoff of lights when you stop the car and get out? This has killed the battery when spouse forgets lights in morning? THX.D.

[73sport]

Buzzing in the rear = BEE'szzzzz in the trunk!!! lol

When I first read this my immediated thought was you are hearing the fuel pump "buzz" which would likely mean its on the verge of going bad (or you're out of gas).

But now I think you might be saying something like an air purge valve is making noise. I'm not sure WHERE ALL they use one way valves in the system excpet the PVC and the gas cap lid itself, but one way valves can "buzz" during flow operations. Perhaps there is something stuck in it or the spring is weak or broken making it make noise? Solenoid valve VVC(??) as Yoda calls them, could possibly make noise too and this are abundant in the system. They are like mechanical relays for air and solids.

As for the battery, need more details on that issue. Or is it the same issue?

[dvp59]

Okay, I raised the car and disconnected the solenoid valve on top of the canister. Now betterhalf will drive it today and tell if it is still making noises. Most of the time it is warm drive mode.I scanned it and closed loop seems to be working. mileage is 28-29, not bad for mixed driving on 10%ethanol.I would like to make certain it is not siphoning fuel here. Btw it has 162k miles.

[dvp59]

She said today,"that is still making the buzzing noise'.This is with the vsv unplugged? The fuel tank level doesn't affect the noise. It does sound like something purging, and going off and on. But while laying under it on ramps, it won't make a sound. It does seem more often now, so maybe that is progress? I sure question the locating of the emission controls on this type car, especially the tank...D.

[dvp59]

Okay, yesterday when the car came home, put it on ramps and cranked it up. The buzzing started too, as the car was still in closed loop. It felt like the black round diaphram was vibrating on top of the emissions box over the axle. This only lasted for seconds and quit , not to repeat it self.Now if I can find detail to repair, replace or disable this diaphram.. will keep looking at files, but has anyone done this?I do not want to replace the whole box assembly, since it is expensive....

[dvp59]

She said the new code showing on the autoscanner is 441.. I have got to figure out the diaphram on top of the canister.Maybe it had a hidden vacumn line, it sure is in a bad location.?What a pain, after years of good quiet driving. D.

[fenixus]

P0441 = EVAP Control System Improper Purge Flow.

check Diagnostics manual, page 129 for 4-cyl:
http://www.camrystuff.com/manuals/Gen4/Diagnostics.pdf

DTCs P0441 and P0446 are recorded by the ECM when evaporative emissions leak from the components
within the dotted line in fig. 1 below, or when there is a malfunction in either the VSV for EVAP, the VSV for
vapor pressure sensor, or in the vapor pressure sensor itself.

Trouble Area:
-Open or short in VSV circuit for vapor pressure sensor
-VSV for vapor pressure sensor
-Open or short in vapor pressure sensor circuit
-Vapor pressure sensor
-Open or short in VSV circuit for EVAP
-VSV for EVAP
-Vacuum hose cracks hole blocked damaged or
disconnected ((1), (4), (5) holed (6) and (7) in fig. 1)
-Charcoal canister cracked, holed or damaged
-Fuel tank over fill check valve cracked or damaged

VSV for EVAP is under hood, on right below the air cleaner box.

hope it helps a bit.

[dvp59]

Well just left our local Toyota dealer, the gas cap is $20.00 and the entire canister for the rear was $279.00 plus taxes...It had all the switches attached, plus an extra piece . I did not realize just how complicated a rig it
was until I saw it on the counter..I shall lay under it again tonight, with a better light.The diaphrams were not available loose or seperate.So now I shall check it all for cracks or hose problems again.D.