I have an 06 Ford Explorer 4.6L with 222k miles. I have codes P01633 (power supply to the KAM fuse) and P0446 (Evap system vent control circuit). I've replaced the vent valve solenoid and the kam fuse. from what I've found it sounds like the evap canister is tied to the same fuse (#24) as the keep alive memory) I cant get rid of the codes and i can't figure out how to fix this. any suggestion's on how to fix it?
Probably best to start with the basics.
The PCM will immediately throw that code if the KAPWR (Keep Alive Power) voltage to the KAPWR pin on the PCM drops below 10.5 volts.
Before the first start of the day, (when the battery has sat all night) maybe grab a multimeter and check your battery voltage.
Next, have someone crank the engine and observe the battery voltage during cranking.
The multimeter voltage reading on a healthy battery won't drop below 10.5 volts during cranking.
Then repeat the same procedure on fuse #24.
Check the voltage at that fuse. Then check it during cranking.
If everything checks out OK the next step would be to measure the voltage at the PCM's KAPWR pin connector to be sure there isn't an Open in the wire between fuse #24 and the PCM.
(you may have to subscribe to an OEM information service like ALLDATA DIY for that PCM pinout info)
While you're under the hood clean your battery terminals and battery cable clamps and tighten them up good.
