2001 Camry - No power to evap canister
 

2001 Camry 4 cylinder, with 175,000 mi. Most of it's life it has had an Check Engine Evap Code showing. Trying to diagnose the problem I disconnected the power connector to the charcoal canister and energized it with a 9v battery. It clicks fine. Checked power connector with multimeter and NO POWER is going to canister when key is turned on in the ignition.

Now what should I be looking at? Blown fuse, bad relay, broken wire?

I'm kinda lost at this point. Any help appreciated

The canister is only powered at certain times via computer.

What was the code?

I currently have a code P0441, although in the past I have gotten other evap codes.

I have also replaced the filler cap with a genuine Toyota cap hoping it would help. It did not, but I will say that the new cap is VERY tight when screwed on to the "click" sound. Sometimes I can hardly unscrew it by hand.

Could it be that the filler pipe is not sized properly and is not letting the cap seal correctly? It does not appear to be damaged in any way.

P0441: Evaporative Emission Control System Incorrect Purge Flow

The EVAP system has a leak, electrical, sensor or switch issue causing the pressure in the charcoal canister to be incorrect compared to outside air pressure.

Issues include:
-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
-Charcoal canister cracked, holed or damaged
-Fuel tank over fill check valve cracked or damaged

The fuel cap is not among the issue listed.

Check for damaged, cracked/damaged vacuum hoses or canister.

Make sure the electric valves (called VSV) for the vacuum hoses are working, as in opening and closing the valve. One is on the canister for the vapor pressure sensor. Another VSV is connected to the vacuum hose going to the throttle body.

The canister stores fuel fumes from the tank. Then when signaled by the ECU, the VSV for the hose going to the throttle body opens to draw out the fumes to be burned.